The TIPS are produced as a public service by the Florida Section of the Institute of Transportation Engineers, John T. Izzo, P.E., editor. The TIPS are published in the Florida Section Institute of Transportation Engineers newsletter, FSITE, and are reprinted by the Florida Technology Transfer (T2) Center at the University of Florida.
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1. TRAFFIC SIGNAL - "Won't a 'Traffic Signal' Reduce Accidents at Our Intersection?"
2. STOP SIGNS - "Won't a 'Stop Sign' Slow Traffic on Our Streets?"
4. CHILDREN AT PLAY SIGNS - "Won't a 'Children at Play' Sign Help Protect Our Kids?"
5. SPEED BUMPS - "Why Can't We Use 'Speed Bumps' on Our Block to Reduce Speed?"
8. HIGHWAY SIGNS - "Have You Thought About the Impact of 'Highway Signs' on Traffic Safety?"
13. CONSTRUCTION SIGNS - "Why Are Those Orange Signs Around Road Construction Sites?"
14. TRAFFIC SIGNALS - "How Do 'Traffic Signals' Work?"
16. TWO-WAY LEFT-TURN LANES - "Why Are 'Two-Way Left-Turn Lanes' Used?"
17. DRIVEWAYS - "Why Limit the Number of Driveways?"
18. TURN LANES - "Why Are 'Turn Lanes' Used?"
23. FIRE LANES - "Why Are 'Fire Lanes' Needed?"
24. HIGHWAY CAPACITY LEVEL OF SERVICE - "What Is Meant by 'Highway Capacity' and 'Level of Service'?"
25. PEDESTRIAN SAFETY - "What Can a Pedestrian Do to Reduce Pedestrian Accidents?"
26. TRAFFIC ENGINEERING - "What Is 'Traffic Engineering'?"
30. DEVELOPMENT OF REGIONAL IMPACT - "What Is a DRI?"
31. LOCAL GOVERNMENT COMPREHENSIVE PLAN - "What Is a Local Government Comprehensive Plan?"
32. FUNCTIONALLY CLASSIFIED ROAD SYSTEM - "What Is the Functionally Classified Road System?"
33. FUNDING FOR TRANSPORTATION - "How Are Transportation Projects Funded?"
38. CONCURRENCY - "What Is Concurrency?"
39. PASSER-BY TRIPS - "What Are 'Passer-By' Trips?"
41. TRANSPORTATION SYSTEM - "What Can Be Done to Develop a Safe and Efficient Transportation System?"
43. CLOSED LOOP SYSTEM - "What Is a Closed Loop System?"
47. TRAFFIC PROJECTIONS - "How Do You Know How Much Traffic is Going to be on a Road in 10 Years?"
49. ACCESSIBILITY REQUIREMENTS MANUAL - "What is the Accessibility Requirements Manual?"
50. TRAFFIC IMPACT STUDY RADIUS - "What is the Radius for a Traffic Impact Study?"
52. "What Transportation Activities can be Implemented to Improve the Environment?'
53. "Why is Landscape Design & Maintenance Important in Private Parking Lots?"
56. TRANSPORTATION DEMAND MANAGEMENT - "What is Transportation Demand Management?"
57. DUI-FACTS - "What are the Facts about Florida's DUI Law?"
58. MITIGATION FOR TRAFFIC CONGESTION - "What are the Mitigation Techniques for Traffic Congestion?"
59. ACCESS MANAGEMENT - "What are Florida's New Access Management and Driveway Connection Standards?"
60. ITS - "What is an Intelligent Transportation System?"
61. TRAFFIC FLOW - "What are the Techniques to Improve Traffic Flow in Urban Areas?"
62. PEDESTRIAN SIGNALS - "How Do Pedestrian Signals Work?"
63. OLDER DRIVERS - "What are Traffic Engineers Doing to Help Older Drivers?"
64. ROADWAY CLASSIFICATION - "What are the Distinctions Among Arterial, Collector and Local Roads?"
65. TRAFFIC VIOLATIONS - "What is the Fine For ... ?"
68. LEFT TURN ARROW - "What is the Justification for a Left Turn Arrow?"
71. METRICATION - "What is Metrication?"
72. ITS ACRONYMS - "What Acronyms are Used for Intelligent Transportation Systems (ITS)?"
74. WHY ARE TRAFFIC ENGINEERS RELUCTANT TO INSTALL "DEAF CHILD" OR "BLIND CHILD" WARNING SIGNS?
79. WHAT IS THE STRATEGIC HIGHWAY RESEARCH PROGRAM (SHRP)?
80. WHAT TYPES OF LAMPS ARE USED FOR ROADWAY LIGHTING?
81. WHAT IS MAGLEV?
83. WHAT ARE TRAFFIC CONTROL ISLANDS?
84. ROUNDABOUTS
85. WHAT ARE TRAFFIC VOLUME COUNTS AND WHAT ARE THEY USED FOR?
Traffic signals don't always prevent crashes. In many instances, the total
number of crashes and injuries increase after they're installed.
Where signals are used unnecessarily, the most common results are a reduction
in right-angle collisions but an increase in total crashes, especially the
rear-end type collision. In addition, pedestrians are often lulled into a false
sense of security.
In deciding whether a traffic signal will be an asset and not a liability,
traffic engineers evaluate the following criteria:
While a properly placed traffic signal improves the flow and decreases
crashes, an unnecessary one can be a source of danger and annoyance to all who
use an intersection: pedestrians, cyclists and drivers.
Stop signs installed in the wrong places for the wrong purposes usually
create more problems than they solve.
One common misuse of stop signs is to arbitrarily interrupt traffic, either
by causing it to stop or by causing such an inconvenience that motorists are
forced to use other routes. Studies made in many parts of the country show that
there is a high incidence of intentional violations where stop signs are
installed as "nuisances" or "speed breakers". These studies showed that speed
was reduced in the immediate vicinity of the "nuisance" stop signs. But,
speeds were actually higher between intersections than they would have
been if these signs hadn't been installed.
At the right place and under the right conditions, a stop sign tells drivers
and pedestrians who has the right of way. Nationally recognized standards have
been established to determine when stop signs should be used. These standards,
or "warrants", take into consideration, among other things, traffic speed and
volume, sight distance and the frequency of traffic "gaps" which will allow safe
vehicle entry or pedestrian crossing.
Most drivers are reasonable and prudent. But, when confronted with
unreasonable restrictions, they frequently violate them and develop a general
contempt for all traffic controls--often with tragic results.
At first consideration, it might seem that this sign would provide protection
for youngsters playing in a neighborhood. It doesn't.
Studies made in cities where such signs were widely posted in residential
areas show no evidence of having reduced pedestrian crashes, vehicle speed or
legal liability. In fact, many types of signs which were installed to warn of
normal conditions in residential areas failed to achieve the desired safety
benefits. Further, if signs encourage parents with children to believe they have
an added degree of protection--which the signs do not and cannot provide--a
great disservice results.
Obviously, children should not be encouraged to play in the roadway. The
"children at play" sign is a direct and open suggestion that it is acceptable to
do so.
Federal standards discourage the use of "children at play" signs.
Specific warnings for schools, playgrounds, parks and other recreational
facilities are available for use where clearly justified.
The speed bump is an increased hazard to the unwary ... a challenge to the
daredevil ... a disruption of the movement of emergency vehicles ... and the
cause of an undesirable increase in noise.
Courts have held public agencies liable for personal injuries resulting from
faulty design. Because speed bumps have considerable potential for liability
suits, many officials have rejected them as a standard traffic control device on
public streets.
In addition, tests of various experimental designs have demonstrated the
physical inability of a speed bump to successfully control all types of
light-weight and heavy-weight vehicles. The driver of a softsprung sedan is
actually encouraged to increase speed for a better ride over a bump that may
cause other motorists to lose control.
The control of speeding in residential neighborhoods is a widespread concern
which requires persistent law enforcement efforts ... not speed bumps.
Bikeways have created a lot of interest in recent years. Some agencies have
built separate off-road bike paths, while many more have painted bike lanes on
streets. Other communities have installed green "Bike Route" signs in
neighborhoods and park systems without the special lanes. Different types of
bike facilities meet the needs of different types (classes) of bicyclists.
Experienced adult bicyclists prefer to ride on the road with
the flow or traffic, with bike lanes to separate them from motor vehicles.
Novice or child bicyclists prefer off-road bike paths.
The cost of building and maintaining bikeways can be a deterrent to may bike
programs. Initial cost can range from a few dollars to paint a lane, to a small
fortune to build a separate path including special bridges and railings where
needed. Funding may be available from ISTEA or "Roadway Enhancement" funds. Such
projects must be submitted through an established procedure.
An overall bicycle safety program should include: enforcement of traffic
laws: bike safety training in the schools at an early age: follow-up training
every year in the schools and involvement of the parents of minor children who
violate traffic laws or exhibit dangerous riding habits.
The bike program for a community should include three principal features:
Education in safety riding practices
Enforcement of rules of the road
Development of well-engineered bike lanes and bike paths
This will involve the active participation of:
School Officials
Law Enforcement Officials
Traffic Engineers and of course, you, the citizen
REMEMBER: AT NIGHT, FLORIDA LAW REQUIRES LIGHTS ON BOTH THE FRONT AND REAR OF
ALL BICYCLES. (Over 60% of Florida bike fatalities occur at night.)
(Revised 12/95)
State law requires traffic control devices, including those signs and
pavement markings on private property where the public is invited, to meet
State standards adopted by the Florida Department of Transportation. Florida
Statutes, Section 316.0747 state: "It is unlawful for any nongovernmental entity
to use any traffic control device at any place where the general public is
invited, unless such device conforms to the uniform system of traffic control
devices adopted by the Department of Transportation pursuant to this Chapter."
The "MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES" (MUTCD) published by
the U.S. Department of Transportation is the national standard for Traffic
Control Devices. The Florida Department of Transportation has adopted the MUTCD
as the State standard by Rule 14-15.10.
The "MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES" may be purchased for
$44.00 plus $5.00 shipping and handling from: Institute of Transportation
Engineers, 525 School Street, S.W., Suite 410, Washington D.C. 20024-2729.
Phone: (202) 554-8050.
The MUTCD states that: Parking space striping must be white (Sec.
3B-19).
Lane Lines between traffic lanes in the same direction, must be
white (Sec. 3B-2).
Centerlines between traffic in opposing direction, must be
yellow (Sec. 3B-1).
Arrows on the pavement must be white (Sec. 3B-20).
Crosswalks and Crosswalk lines must be white (Sec. 3B-18).
Stop Lines (Stop Bars) must be white (Sec. 3B-17).
Street Name Signs must have 4" high lettering and should be
reflectorized (Sec. 2D-39).
SIGN INSTALLATION: In business, commercial or residential
districts where parking and/or pedestrian movement is likely, the clearance
to the bottom of a sign shall be at least 7 feet above the edge of the
pavement. In rural areas, the clearance to the bottom of a sign shall
be at least 5 feet above the edge of the pavement (Sec. 2A-23).
Lateral clearance for regulatory and warning signs or small
directional signs should be 6 to 12 feet from the edge of the pavement or
traveled way in rural areas. In urban areas, signs generally are
mounted alongside the roadway in the space between the curb and the sidewalk.
Although 2 feet is recommended as a working urban minimum, a
clearance of 1 foot from the curb face is permissible where sidewalk
width is limited (Sec. 2A-24).
STANDARD SIZES, (SHAPES) AND ORDER CODES OF SIGNS:
STOP: 30" (OCTAGON), ORDER CODE R1-1
YIELD: 36" (EQUILATERAL TRIANGLE), ORDER CODE R1-2
NO TURN (SYMBOL): 24"x24" (SQUARE), ORDER CODE R3-1R, R3-2L OR R3-3
DO NOT ENTER: 30"x30" (SQUARE), ORDER CODE R5-1
REGULATORY (SPEED LIMIT, KEEP RIGHT): 24"x30" (RECTANGLE), ORDER CODE R2-1,
R4-7
WARNING (RIGHT OR LEFT CURVE, NO OUTLET...): 30"x30" OR 36"x36" (DIAMOND)
STREET NAME: 6" HIGH WITH/4" HIGH LETTERING (RECTANGLE), ORDER CODE D3-X
HANDICAPPED PARKING: 12"x18" (RECTANGLE), ORDER CODE R7-8
ONE WAY: 36"x12" OR 18"x24" (RECTANGLE), ORDER CODE R6-2R (OR L); R6-1R (OR
L)
As a motorist or pedestrian, have you noticed changes in traffic signs you
see along the roadways? New colors, shapes, symbols and messages are now helping
you as the result of many years of worldwide research and engineering
development by Transportation Engineers.
The MANUAL ON UNIFORM TRAFFIC CONTROL DEVICES (MUTCD) gives
Transportation Engineers the uniform standards to safely assist motorists as
they travel. It defines a series of uniform signs which are clear in their
messages as applied on the nation's roadway system.
Symbols have replaced word messages whenever appropriate. The MUTCD
has adopted standard sign and pavement marking colors and shapes to help today's
motorists to better understand the rules of the road.
The use of specific colors is designed to promote instant recognition of sign
and pavement markings messages.
The color RED, is used exclusively to indicate a stop or prohibition.
The red "STOP" and "DO NOT ENTER" signs are examples of a "Stop message", while
red on white parking signs indicate that parking is not allowed.
GREEN is the color which indicates a "Go" condition, or gives the
motorist directional guidance. Virtually all guide signs on the Interstate
System have a green background and local roadways are following suit. A parking
regulation sign with green text indicates that parking is allowed.
BLUE is a sign color which directs motorists to services that are
available. The "H" hospital sign, the telephone symbol sign, as well as
food-gas-lodging signs which are located at many highway interchanges are
examples of this use.
YELLOW is used for warning signs which alert the motorist to a
changing condition in the roadway ahead. "SIGNAL AHEAD", "SCHOOL CROSSING", "LOW
CLEARANCE", and "NO PASSING" zone signs are examples.
A BLACK LEGEND ON A WHITE BACKGROUND indicates a regulation. "LEFT
LANE MUST TURN LEFT" and "SPEED LIMIT 55" are typical examples.
ORANGE signs indicate that a motorist is approaching a construction
and/or maintenance area.
BROWN is the background color for information about public parks and
recreational areas.
Transportation Engineers have also reserved the shape of traffic control
signs for specific types of messages. With only a quick glance, a motorist can
tell the type of message by the shape of the sign.
The DIAMOND shaped sign is always used to issue a warning to the
motorist. This diamond sign can warn of a pedestrian crossing, traffic signals,
slippery pavement or curve in the roadway.
A RECTANGULAR sign with its longer side vertical signifies a traffic
regulation. "KEEP RIGHT", "DO NOT PASS" and "NO U TURN" signs are examples.
RECTANGULAR SIGNS with the longer dimension horizontal are intended to
give guidance information. "BIKE ROUTE", "FOOD-PHONE-GAS-LODGING", and
directional signs fall into this category.
An OCTAGON is only used for a "STOP" sign and has no other legal use
relative to traffic control devices.
An INVERTED TRIANGLE is the only way the Transportation Engineer
signifies a "YIELD" condition.
A PENNANT shaped sign indicates that "NO PASSING" is allowed.
A PENTAGON sign is restricted to school zones. A pentagon sign with
the silhouette of children walking signifies the beginning of school property
while the same sign, with the addition of a crosswalk shown on it, indicates the
school crossing point.
A CIRCULAR sign is used only at railroad crossings.
Strict criteria have been developed by the Florida Department of
Transportation to control the use of traffic generator signs such as those used
to guide traffic to business establishments.
Transportation Engineers attempt to minimize the amount of time a motorist's
eyes must be diverted from the roadway to perceive sign messages. The next time
you take a ride through your area, take a good look at the highway signs. They
are examples of how Transportation Engineering research works to make your
driving safer.
Pavement markings have definite and important functions to perform in
the area of traffic control. They may be used to supplement the regulations or
warnings of other devices, such as the use of stop bars in conjunction with
traffic signs or signals. They may be used alone to produce results that cannot
be obtained by any other device, such as guidance on winding roads and around
fixed objects near the highway.
The Federal Highway Administration adopted the "MANUAL ON UNIFORM TRAFFIC
CONTROL DEVICES" to provide a standard for traffic control devices. This
manual has been adopted by most states including Florida.
Pavement markings are generally yellow or white in color. Yellow
lines delineate the separation of traffic flows in opposing directions or
mark the left boundary of the travel path at locations of particular hazard.
White lines delineate the separation of traffic flows in the same
direction.
Solid lines are restrictive, with double lines indicating maximum
restriction. Broken lines are permissive. Line width also has
importance, indicating the degree of emphasis with which the local traffic
authorities are placing on traffic control. Some of the more common markings
are:
A solid yellow line delineates the left edge of a travel path. It
indicates a restriction against passing on the left or delineates the left edge
of pavement on a divided street or highway, where there is inadequate clearance
to the left of the line for making emergency stops. A double line consisting of
two solid yellow lines delineates the separation between travel paths in
opposite directions where passing is prohibited in both directions.
Crossing this marking with care is permitted only as part of a left-turn
maneuver.
A broken yellow line is used to delineate the left edge of a travel path
where travel on the other side of the line is in the opposite direction. The
usual application is as the center line of a two-lane, two-way roadway where
overtaking and passing is permitted.
A double line consisting of a broken yellow line and a solid yellow line
delineates a separation between travel paths in opposite directions where
overtaking and passing is permitted for traffic adjacent to the broken line
and is prohibited for traffic adjacent to the solid line. It is used on two-way,
two and three-lane roadways to regulate passing.
A broken white line is used to delineate the edge of a travel path where
travel is permitted in the same direction on both sides of the line. Its
most frequent application is as a lane line.
A solid white line is used to delineate the edge of a travel path
where travel in the same direction is permitted on both sides of the line but
crossing the line is discouraged. The solid white line is also used as a
pavement edge marking. A wide solid white line is used for emphasis where
the crossing requires unusual care. It is often used as a line to delineate left
or right turn lanes.
A double solid white line is used to delineate a travel path where travel
in the same direction is permitted on both sides of the line, but crossing
the line is prohibited. It is used as a channelizing line in advance of
obstructions which may be passed on either side.
On occasion, a broken line is used to delineate the extension of a line
through an intersection or interchange area. It has the same color as the
line it extends.
Raised Reflective Pavement Markings (RPM's) have been found to be very
effective in marking roadway centerlines and lane lines especially at night and
during periods of rain.
Circumstances sometimes require more unusual treatments. Reversible
lanes, inbound in the morning and outbound at night, and the reservation of
a left-turn only lane in the center of a highway are examples of such
conditions. A double broken yellow line delineates the edge of a lane in
which the direction of travel is changed from time to time. In "left turn
only" lanes, yellow markings are placed with solid lines on the outside and
broken lines on the inside of the lane. Traffic adjacent to the solid line may
cross this marking only as part of a left-turn maneuver.
Pavement markings such as shoulder markings, word and symbol markings,
stop lines, crosswalk lines and parking space markings are white with the
following two exceptions:
1. Transverse median markings are yellow.
2. Line, word and symbol markings visible only to traffic proceeding in the
wrong direction on a one-way roadway are red. This type of marking is found on
exit ramps or high speed, limited access roadways.
AND NEWSPAPER DELIVERY BOXES?
Each year, 70 to 100 people are killed in crashes involving rural mailboxes.
Many victims that are not killed are often blinded and disfigured for life
because mailboxes and their supports penetrate the windshield and hit the victim
in the face.
Mailbox owners are limited only by their imagination. Steel tractor wheels,
water pumps, milk cans filled with concrete, chains and massive I-beams are a
few devices used to support mailboxes. Although such supports may be artistic to
some, most are serious roadside hazards to motorists.
In a publication entitled "The Law and Roadside Hazards" Sponsored by the
Insurance Institute for Highway Safety, it is stated that "Private
individuals and corporations, as well as governmental entities, may be liable
for their roles in creating or maintaining highway hazards."
The use of massive rigid mailbox supports such as bricks around the
mailbox, heavy metal posts, concrete posts, and items of farm equipment, such as
milk cans filled with concrete must not be used.
In Florida, uniform minimum standards and criteria for the design
construction and maintenance of all public streets, is presented in the
"Manual on Uniform Minimum Standards for Design, Construction and Maintenance
for Streets and Highways." This publication, referred to as the "Green
Book", developed by the Florida Department of Transportation, states that
guidelines for the location of mailboxes and the types of support are given in
the AASHTO publication "A Guide for Erecting Mailboxes on Highways -
1984". The FDOT "Green Book" also states that Geometric Design
Objective #6 is to: "Provide a hazard-free environment that is "forgiving" to
a vehicle that has badly deviated from the travel path or is out of
control."
The following support and location standards for mailboxes and newspaper
delivery boxes are from the AASHTO to publication entitled "A Guide for Erecting
Mailboxes on Highways" (5-24-84):
WOOD POSTS: 4" diameter if round; 4 x 4" if rectangular
METAL PIPES: 2" inside diameter (maximum) standard steel, or aluminum.
NUMBER OF SUPPORTS: Use only 1 support for 1 box or group boxes.
Supports Should:
1. Yield or collapse if struck.
2. Bend or fall away from vehicle.
3. Not create severe deceleration.
4. Not be fitted with an anchor plate (metal post).
5. Not be embedded over 24" into the ground.
6. Not be set in concrete.
LOCATION OF MAILBOXES OR NEWSPAPER DELIVERY BOXES
1. Should be on right side of road in direction of delivery travel.
2. Servicing vehicle should be removed from roadway.
3. Mailbox face should be no closer than edge of shoulder (8'from roadway).
4. Mailbox should not block sight distance.
5. Mailbox should be behind existing guardrail if possible.
6. Should be mounted 3' to 4' above the mail stop surface.
In Florida, over 250,000 traffic crashes each year account for approximately
2,900 fatalities, 217,000 nonfatal injuries and $600 million dollars in property
damage.
Citizens can do their part to help reduce the high cost of traffic crashes by
taking the following actions:
DRIVE CAREFULLY - Concentrate on driving and use seat belts; do not
speed or drink and drive.
DON'T TAKE CHANCES - Play it safe. Drivers should not try to "beat the
light" or "beat the train" at railroad crossings. Drive defensively at all
times.
REPORT ROADWAY HAZARDS as soon as possible to city, county or state
officials responsible for road maintenance and safety. Roadway hazards that
should be reported are:
REPORT ACTS OF VANDALISM to law enforcement, traffic engineering and
maintenance officials.
SUPPORT TRAFFIC SAFETY OFFICIALS to insure that they have adequate
budgets for staff, equipment and supplies to do their job properly.
TURN ON VEHICLE HEADLIGHTS between dusk and dawn and anytime
visibility is reduced by rain, smoke, fog, etc.
KEEP VEHICLES IN GOOD MECHANICAL CONDITION by regularly checking
brakes, tires, wipers and other safety equipment.
OBEY TRAFFIC CONTROL DEVICES such as signs, signals and pavement
markings. These devices were installed to enhance safety.
In Florida, during 1985, crashes involving trees accounted for 230
fatalities and 7,905 non-fatal injuries. Trees must sometimes be removed
near a roadway in order to improve the sight distance, which is the length of
road ahead visible to the driver.
Many traffic crashes involving trees occur when vehicles run off roadways
with little or no roadside clear zone. The roadside clear zone has been
defined by the Florida Department of Transportation (FDOT) as "that area
outside the traveled way available for use by errant vehicles." Vehicles
frequently leave the traveled way during avoidance maneuvers, due to loss of
control by the driver or due to collisions with other vehicles. Common
circumstances that may cause a driver to run off the roadway can be driver or
environment related. Driver related contributing circumstances which
may cause a vehicle to stray off the roadway include: improper passing, alcohol
or drug involvement, falling asleep, driver inattention, or driver distraction.
Environment related contributing circumstances which may cause a vehicle
to run off the roadway include: debris in roadway, glare, holes or ruts in
roadway, slippery surface, water ponding or animal in path of the vehicle.
A manual was developed by the FDOT to provide uniform minimum standards and
criteria for the design, construction and maintenance of all public streets. The
manual often referred to as the "FDOT Greenbook," is entitled "Manual
of Uniform Minimum Standards for Design, Construction and Maintenance of Streets
and Highways." The standards presented in the manual are intended to provide
the basic guidelines for developing and maintaining a highway system. Objective
#6 of the manual is to "Provide a hazard-free environment that is forgiving"
to a vehicle that has badly deviated from the travel path or is out of
control." Page III-35 of the manual states that "the width of the roadside
clear zone should be made as wide as is practicable. The minimum permitted
widths are given in Table III-12. These are minimum values only and should be
increased wherever feasible."
The FDOT standards require a minimum width of roadway clear zone in
accordance with the design speed of the roadway and the type of area, rural or
urban.
In rural areas, with a roadway design speed below 35 MPH, a minimum
clear zone width of 6 feet is required. For a design speed of 35, 40 and 45 MPH,
a minimum clear zone width of 8, 11 and 14 feet respectively, is required. For a
design speed of 50 MPH and above, a minimum clear zone width of 30 feet is
required. In urban areas, with a roadway design speed of 45 MPH or less,
a minimum clear zone width of 4 feet is required. The 4 foot minimum required
clearance area applies to the placement of trees behind curbed islands and
roadway edge. For a design speed of 50 MPH and above, a minimum clear zone width
of 14 feet is required.
In summary, trees in the roadside clear zone can be harmful in two ways:
Trees can prevent vehicle recovery to the roadway and increase injury
severity and property damage when crashes do occur. Good traffic engineering
practice and state standards require that an adequate roadside clear zone be
provided on all new road construction projects. This requires that the roadside
clear zone to be clear of trees and other fixed objects.
Whenever work is done on or near the roadway, drivers are faced with changing
and unexpected traffic conditions. These changes may be hazardous for drivers,
workers and pedestrians unless protective measures are taken.
Drivers and pedestrians should take special care to observe signs, signals,
pavement markings and flagmen, near roadway construction sites. These traffic
control devices are installed to assist and safely guide and protect motorists,
pedestrians and workers in a traffic control zone.
Most traffic control zones are divided into the following areas:
Transition Area - moves traffic out of its normal area.
Buffer Space - provides protection for traffic and workers.
Work Area
Termination Area - lets traffic resume normal driving.
Warning Signs are used to give notice of conditions that are
potentially hazardous to traffic. These signs are used particularly when the
danger is not obvious or cannot be seen by the motorist. Warning signs are
typically diamond-shaped with one diagonal vertical. Permanent warning
signs have a black legend on a yellow background. Construction and
maintenance warning signs are a special series with the black legend on
an orange background. The orange color is used to indicate the
temporary nature of the condition and the additional potential hazard of the
worksite. Traditionally, work activities have included construction,
maintenance, and utility operations. However, orange color warning signs may
have application for all work activities within the right of way such as survey
crews or temporary weighing stations.
Guide Signs show destinations, directions, distances, services, points
of interest and other geographical information. Directional signs and street
name signs, when used with detour routing, may have a black legend on an
orange background. Special information signs relating to the work
being done shall have a black message on an orange background.
When installed under conditions that justify its use, a traffic signal
is a valuable device for traffic control. However, an ill-advised or
poorly designed signal is not only annoying, but can be dangerous to
pedestrians, cyclists and drivers. Therefore, it is essential that, before
traffic signals are installed, engineering studies be made by qualified
personnel.
A traffic signal provides alternate right-of-way for different traffic
movements at an intersection. It provides a degree of control that is second
only to physical barriers. A good general guide is to use the least traffic
control required to provide for the safe and efficient movement of vehicles and
pedestrians. Specifications for signals and their placement as well as
warrants for their use are contained in a publication entitled "Manual on
Uniform Traffic Control Devices" published by the U.S. Department of
Transportation.
A signal that minimizes vehicle stops and delay also cuts fuel consumption
and emissions. The signal controller switches the signal indications on and
off to assign right-of-way correctly and safely. Two basic kinds of
controllers are used: pretimed (also known as fixed-time) and
traffic-actuated.
Pretimed controllers operate on a predetermined, regularly repeated
sequence of signal indications. They are used frequently where traffic
volumes are predictable and stable.
Traffic-actuated controllers differ from pretimed controllers in that
their signal indications are not of fixed length, but change in response to
variations in traffic demand. They are frequently used where traffic volumes
fluctuate widely or irregularly, or where interruptions to major-street flow
must be minimized.
Signal Timing is the division of the cycle into seconds for each of
the phases. It assigns right-of-way to alternate traffic movements in order to
reduce traffic delay and crash-producing conflicts. Signal timing is constrained
by the cycle length - the time for one complete sequence of the
signal indications. Cycle lengths usually fall between 45 and 120 seconds.
There are three common techniques for coordinating traffic signals to
operate as a system. This is done to improve the progressive flow of traffic
along an arterial street or in a network, any of which can work with either
pretimed or actuated controllers.
The simplest system is the basic programmed system in which a master
controller simply sends a periodic pulse to all intersections to instruct the
local controllers that this is the system reference point.
The second method, called "time based coordinators," replaces the
central controller and the interconnecting communications completely and places
a very accurate timer directly at each location.
The third system uses a sophisticated central computer control that exerts
more external control on the individual controllers.
Traffic engineers have received calls from concerned citizens asking
"Aren't those new STOP signs rather high?
In Florida, as in most states, the standard for signs, signals and pavement
markings is the "Manual on Uniform Traffic Control Devices" (MUTCD). This
publication by the U.S. Department of Transportation, serves as the standard for
the installation of all traffic control devices.
The MUTCD indicates that "in business, commercial and residential districts
where parking and/or pedestrian movement is likely to occur or where there are
other obstructions to view, the clearance to the bottom of the sign shall be at
least 7 feet." "Signs erected at the side of the road in rural districts shall
be mounted at a height of at least 5 feet, measured from the bottom of the sign
to the near edge of the pavement."
"Why must signs be so high?" One major reason is the improved
visibility that results. In urban areas, parked cars and other obstructions
often obscure signs that are too low. Also, pedestrians are not likely to
collide with properly mounted signs under conditions of reduced visibility
(darkness). In rural areas, bushes and even weeds can block signs that are
installed too low.
Another reason for installing signs high enough is the improved condition and
life of the sign. A sign 7 feet above the ground is less susceptible to
vandalism. It is also less likely to be sprayed with dirt from passing cars. And
finally, signs mounted at their correct height have been found to command more
respect than those that are too low.
Another concern of citizens is the lateral placement of STOP signs from the
roadway.
The MUTCD states that "signs should have the maximum practical lateral
clearance from the edge of the traveled way for the safety of motorists who may
leave the roadway and strike the sign support." It is further stated that
"Normally, signs should not be closer than 6 feet from the edge of the shoulder,
or if none, 12 feet from the edge of the traveled way. In urban areas, a lesser
clearance may be used where necessary. Although 2 feet is recommended as a
working urban minimum, a clearance of 1 foot from the curb face is permissible
where sidewalk width is limited or where existing poles are close to the curb."
The two-way left-turn lane, a device for increasing capacity and safety, is
being more frequently used throughout Florida and other states. As its name
implies, this is a marked lane that is used for left turns by traffic going in
both directions on a street. A significant benefit can result when it is used on
streets that are lined with commercial development and many driveways.
Despite the initial apprehension which a driver may have, the safety record
of these lanes appears to be good. One study showed that where no median was
previously provided, the installation of continuous two-way left-turn lanes
reduced total crashes by about 33% with reductions of 45% and 62% for head-on
and rear-end type crashes, respectively.
Another study reported that the "head-on collision," which has been a primary
concern among those considering the installation of a continuous two-way
left-turn lane, has proved to be an uncommon occurrence and of negligible
concern.
Drivers use the two-way turn lane by entering only when they are making the
left turn. They do not drive in the lane and therefore do not create a
significant potential for head-on collisions. However, by pulling into the
left-turn lane when making a turn into a driveway, the driver removes himself
from the through lane and this eliminates potential rear-end, side-swipe and
lane-changing crashes. These turn-lanes also increase the capacity of the
street.
Both Federal and State manuals on traffic control devices specifically
provide for the two-way left-turn lane. The markings for the two-way left-turn
lanes are yellow and consist of a dashed line and a solid barrier line on each
side of the lane. The solid line is on the outside of the two-way left-turn lane
and the dashed line is on the inside. This marking tells the driver in the
through lane that he cannot cross the line for the purpose of passing another
moving car, although he can cross into the lane for the purpose of turning left.
A two-way left-turn lane can change into a single direction left-turn lane at
major intersections through a change in marking. The lane markings on the right
side change from the yellow solid-dashed combination into a standard white lane
line used to separate traffic moving in the same direction. The lane markings on
the left would change into a double yellow, the standard used to prohibit
passing in either direction.
White pavement arrows may be used in addition to the lane and barrier
markings to remind drivers that left turns are made in both directions from the
lane. Signs must also be used to supplement the pavement markings.
The use of this relatively new traffic control treatment will increase as
more officials become familiar with it. The two-way left-turn lane is not a
cure-all. However, it is another one of the devices being used by Traffic
Engineers to increase the capacity as well as the safety of our existing street
system.
The fewer driveways on an urban or rural roadway, the more effectively it
will serve its primary function. As traffic volume and roadside development
increase, increasing numbers of driveways cause crash rates to gradually
increase. It has been estimated that about 12% of crashes on major urban
routes are related to commercial driveways.
One accident study showed that as the number of driveways per mile increased,
the crash rate increased:
.2 1.25
2.0 2.70
20.0 17.80
Traffic engineers recognize that elimination of unexpected events and the
separation of decision points simplifies the driving task. Access control
reduces the variety and spacing of events to which the driver must respond.
Controlled access has resulted in improved traffic operations and reduced
crashes.
Based on an analysis of data from 30 states, a report to the U.S. Congress
concluded that full control of access has been the most important single design
factor ever developed for crash reduction.
The effect of control of access on crashes and fatalities in urban and rural
areas is shown below:
Urban Rural
Access Control Total Fatal Total Fatal
Full 1.86 0.02 1.51 0.03
Partial 4.96 0.05 2.11 0.06
None 5.26 0.04 3.32 0.09
Turn lanes at intersections are designed primarily to separate turning
traffic from through traffic. With turn lanes, through traffic is not delayed by
vehicles waiting to turn. By removing the turning vehicles from a through lane,
traffic flow and safety are improved. Turn lanes may also be used to decelerate
vehicles leaving the major street.
Studies have shown that channelization of intersections, with turn lanes,
produced an average of 32.4 percent reduction in all types of crashes. Crashes
involving personal injuries decreased by over 50 percent. One study showed that
intersection channelization projects had produced an average benefit/ cost ratio
of 2.31. Turn lanes at major driveways can also improve efficiency and safety
especially on high volume or high speed roadways. Studies have shown a 52%
decrease in rear end crashes as well as 6% decrease in left turn crashes.
One of the most significant features affecting an intersection's operation is
the treatment of left-turning vehicles. Accommodation of left turns can be
one of the most critical design factors since safety and the level of
service are greatly influenced.
A left turning vehicle can conflict with: a) Opposing through traffic;
b) Crossing traffic; c) Through traffic in the same direction.
The major crash types involved with left turning vehicles are rear end, angle
and sideswipe crashes in the same direction. The capacity of a roadway may be
greatly influenced by how left turning vehicles are handled. Studies have shown
the effect of left-turn lanes on crash rates at intersections. The results of
one study is shown below:
Unsignalized - without left turn lanes 4.3
Unsignalized - with left turn lanes 1.1
Signalized - without left turn lanes 2.5
Signalized - with left turn lanes 1.6
Entering driveway by left turn 246 43
Entering driveway by right turn 26 15
Leaving driveway by left turn 65 27
Leaving driveway by right turn 35 15
In general, the treatment of right-turning vehicles is less critical than
left-turning vehicles due to the higher right-turning vehicle speeds and the
uninterrupted nature of the right-turn maneuver.
If a law officer has reason to suspect a person is driving under the
influence, the person may be requested to submit to: A breath
alcohol test, a urine test for controlled substances and a blood
test for blood alcohol or for controlled substances. If a person refuses a
required breath, urine or blood test, it will result in loss of a person's
driver's license and prosecution for Driving Under the Influence (DUI).
On July 1, 1982, one of the nation's toughest laws on drunken driving took
effect in Florida. This law provided for strict penalties if convicted of
drunken driving. First Convictions provided for:
Fines of at least $250 (with up to $500)
Jail Term up to 6 months
Driver's License revoked at least 6 months (with up to 1 year)
Community service of 50 hours is required
DUI school is required - paid for by the person convicted
Repeated Convictions can provide for: Fines of up to $2,500, jail term
of up to 1 year, Driver's license revoked up to 10 years and DUI school can
require further treatment without court approval
Paying the Toll for DUI can be a sobering experience:
Vehicle Towing $30-50
Bond release from jail $250
Attorney's fees if you plead guilty $350-700
Attorney's fees if you plead not guilty $750-2,000
Witness fees $200-300
Fine for 1st conviction $250-500
Court Costs $26-50
Probation costs $120-300
Alcohol Safety Educational School $50-125
Driver's license reinstatement fee $35
Approximate annual insurance rate
increase for 3 years $1,000
The approach of a new school year brings out old questions on school zones
and school buses.
In Florida, school zones are governed by the Florida Traffic Laws,
Florida Statutes, Section 316.1895. This Statute states that "No school zone
speed limit shall be less than 15 miles per hour except by local regulation.
Such speed limit shall be in force only during those times 30 minutes before and
30 minutes after the times necessary and corresponding to the periods of time
when pupils are arriving at and leaving regularly scheduled school sessions."
The Statute also states that "Permanent signs designating school zones and
school zone speed limits shall be uniform in size and color, and shall display
the times during which the restrictive speed limit is enforced clearly
designated thereon. The Department of Transportation shall establish adequate
standards for the signs."
Different types of speed limit signs are used for school zones in Florida.
Some have flashers which serve the purpose of advising motorists when the school
zones are in effect. When these flashers are set and used properly, they are
very effective. They alert the motorist to the need for caution and slower
driving when the appropriate conditions exist. A school speed limit sign without
flashers, while not as helpful to the motorist, is just as legally binding as
the flasher sign. Drivers are reminded to be especially alert during those hours
when children are on the streets.
Chapter 316.172 of the Florida Statutes indicates that traffic must stop
for school buses. This law states that:
(1) "Any person using, operating, or driving a vehicle on or over the roads
or highways of this State shall, upon approaching any school bus used in
transporting school pupils to or from school which is properly identified in
substantial accordance with the provisions of Florida Statute 234.051 and which
displays a stop signal, bring such vehicle to a full stop while the bus is
stopped, and the vehicle shall not pass the school bus until the signal has been
withdrawn."
(2) "The driver of a vehicle upon a divided highway where the one-way
roadways are separated by an intervening unpaved space at least 5 feet or
physical barrier, need not stop upon meeting or passing a school bus which is on
a different roadway."
1. Stop.
If you are in a crash while driving, you must stop. If anyone is hurt you
must get help.
2. Report The Crash.
If the crash causes injury, death, or property damage of $100.00 or more, it
must be reported. Call the local police or the Florida Highway Patrol. If the
crash involves a charge of driving while impaired (DWI), results in death or
injury, or involves a vehicle rendered inoperative, an officer will fill out a
report.
If no report is written by an officer, you must report the crash to the
Department of Highway Safety and Motor Vehicles within 5 days. The officer will
provide you with a crash form, or you may use the form in the back of the
Florida Drivers Handbook. Keep a copy of the form for your records.
3. Move Your Car If It Is Blocking Traffic.
If your car is blocking the flow of traffic, you must move it. If you cannot
move it yourself, you must get help or call a tow truck. This is true anytime
your vehicle is blocking the flow of traffic, whether it has been involved in a
crash or not.
4. Appear In Court.
If you are involved in a crash, you will probably have to go to court. The
officer who comes to the scene of the crash will file charges against any driver
who broke a traffic law.
Anyone who is charged will have a chance to explain to the court what
happened. The court will then decide what the penalty will be. Anyone who is not
charged with breaking a law will usually have to come to court as a witness.
A driver leaving the scene of a crash involving death or personal injury will
have his or her license revoked. The driver can also receive a jail sentence.
If while driving, you hit a vehicle with no one in it or if you damage any
object that belongs to someone else, you must tell the owner. Give the owner
your name and address in person or in a note attached to the object that was
hit.
Florida Statute (F.S.) 316.1955, presents the State standard for parking
spaces provided by governmental agencies for certain disabled persons.
This section requires each State agency and political subdivision having
jurisdiction over street parking or publicly owned and operated parking
facilities to provide a minimum number of specially designed and marked motor
vehicle parking spaces for the exclusive use of those severely physically
disabled individuals who have permanent mobility problems and who have been
issued an "exemption entitlement parking permit." This section requires the
minimum number of handicapped parking spaces as shown below:
in Lot Parking Spaces in Lot Parking Spaces
Up to 25 1 201 to 300 7
26 to 50 2 301 to 400 8
51 to 75 3 401 to 500 9
76 to 100 4 501 to 1000 2% of total
101 to 150 5 Over 1000 20% plus 1 for each 100 over 1000
151 to 200 6
State Law now requires all handicapped parking spaces to be "conspicuously
outlined in blue paint" in addition to the above-grade signing. FDOT standards
require the blue outline to be a 4" wide blue stripe to be 2" inside of the
standard 4" white stripe as shown in FDOT Standard Index 17358. This standard
states "USE OF THE PAVEMENT SYMBOL IN HANDICAPPED PARKING SPACES IS OPTIONAL.
WHEN USED, THE SYMBOL SHALL BE 3 TO 5 FT. HIGH AND WHITE IN COLOR." The blue
stripes should match Shade 15180 of Federal Standard 595A.
F.S. 316 also states: "It is unlawful for any person to stop, stand, or park
a vehicle within any such specifically designated and marked parking space
provided in accordance with this section, unless such vehicle displays a parking
permit issued pursuant to s. 316.1958 or s. 320.0848, and such vehicle is
transporting a person eligible for the parking permit." Florida Law provides for
handicapped parking enforcement by stating: "The provisions of handicapped
parking shall be enforced by state, county, and municipal authorities in their
respective jurisdictions whether on public or private property in the same
manner as is used to enforce other parking laws and ordinances by said
agencies." F.S. 316.008 provides for a fine up to $250.00 for drivers who
illegally park in designated handicapped parking spaces.
F.S. 316.1956 presents the State Law in regard to parking spaces provided by
nongovernmental entities for certain disabled persons. This section
states "Any business firm, or other person licensed to do business with the
public may provide specially designed and marked motor vehicle parking spaces
for the exclusive use of physically disabled persons who have been issued
parking permits pursuant to s.316.1958(2)(c)."
An "Application for Disabled Person Parking Permit by Disabled Person" (Form
HSMV 83039) and "Disabled Person's Parking Permit Physician's Statement of
Certification" (Form HSMV 83006) may be obtained through the Florida Department
of Highway Safety and Motor Vehicles, Division of Motor Vehicles, Neil Kirkman
Building, Tallahassee, Florida 32301, or at local tag office.
Some Counties, including Volusia County, require developers to provide for
handicapped parking in accordance with the Standard Building Code. This code
requires the same size and number of spaces as presented in F.S. 316.1955.
REVISED: NOVEMBER 1988
A "Fire Lane," also called an "Emergency Access Lane" is a
driving lane adjacent to a commercial development that is reserved to provide
for emergency access. Parking or standing in a Fire Lane is
prohibited.
The Standard Building Code, Section 602.6, provides the standard for
Fire Lanes. The Code states "Every building hereafter constructed shall be
accessible to fire department apparatus by way of access roadways with
all-weather driving surface not less than 20 ft. of unobstructed width, with
adequate roadway turning radius capable of supporting the imposed loads of fire
apparatus and having a minimum vertical clearance of 13 ft-6 in." The Fire
Prevention Code also states that "The required width of access roadways shall
not be obstructed in any manner, including the parking of vehicles.
Installation of "NO PARKING" signs or other appropriate notice, or of
approved obstructions inhibiting parking, may be required and if installed,
shall be maintained. The owner (or his representative) of a building which is
adjacent to the fire lane shall be responsible for keeping the fire lane free of
obstructions."
The primary purpose of a Fire Lane is to allow emergency personnel and
equipment easy access to a facility.
A secondary benefit of providing a "Fire Lane" or "Emergency Access Lane" is
to improve both pedestrian safety and traffic circulation.
Pedestrian Safety is improved because pedestrians are more visible to
drivers since parked cars do not obstruct the view of the driver.
Traffic Circulation will be greatly improved through the use of a
"Fire Lane" on the main roadway adjacent to a commercial development. No parking
or standing in a "Fire Lane" will decrease the interruption of traffic and will
increase the roadway capacity.
No national standard for Fire Lane signing or marking has been developed;
however, many jurisdictions have developed local standards. A typical standard
for signing and marking Fire Lanes is presented below:
Signing shall be with 12" x 18" "NO PARKING - FIRE LANE" signs with red
lettering on a white background. These signs shall be similar to the "Manual on
Uniform Traffic Control Devices" (MUTCD) R7 Sign Code Series and shall be
installed at a spacing of 50' to 100', along the Fire Lane and shall be plainly
visible to motorists.
Pavement markings for Fire Lanes shall be installed with beaded paint 15 mils
minimum thickness or thermoplastic 90 mils minimum thickness and shall include a
yellow curb throughout the limits of the Fire Lane. The pavement marking legend
shall be "NO PARKING - FIRE LANE" spaced at a maximum of 100' apart. Pavement
marking lettering must be 8' high with 6" strokes in accordance with the MUTCD.
Capacity of a highway is defined in the 1985 Highway Capacity Manual
(HCM), by the Transportation Research Board, as "the maximum hourly rate at
which persons or vehicles can reasonably be expected to traverse a point or
uniform section of a lane or roadway during a given time period under prevailing
roadway, traffic and control conditions." The HCM defines "Level of
Service" (LOS) as "a qualitative measure describing operational conditions
within a traffic stream, and their perception by motorists and/or passengers."
Six Levels of Service for each facility type range from "A" (Best) to
"F" (Worst).
LOS "A" represents free flow. Individual users are virtually
unaffected by the presence of others in the traffic stream. Freedom to select
desired speeds and to maneuver within the traffic stream is extremely high. The
general level of comfort and convenience provided to the motorist, passenger, or
pedestrian is excellent.
LOS "B" in the range of stable flow, but the presence of other users
in the traffic stream begins to be noticeable. Freedom to select desired speeds
is relatively unaffected, but there is a slight decline in the freedom to
maneuver within the traffic stream from LOS "A". The level of comfort and
convenience provided is somewhat less than at LOS "A", because the presence of
others in the traffic stream begins to affect individual behavior.
LOS "C" is in the range of stable flow, but marks the beginning of the
range of flow in which the operation of individual users become significantly
affected by interactions with others in the traffic stream. The selection of
speed is now affected by the presence of others, and maneuvering within the
traffic stream requires substantial vigilance on the part of the user. The
general level of comfort and convenience declines noticeably at this level.
LOS "D" represents high density, but stable flow. Speed and freedom to
maneuver are severely restricted, and the driver or pedestrian experiences a
generally poor level of comfort and convenience. Small increases in traffic flow
will generally cause operational problems at this level.
LOS "E" represents operating conditions at or near the capacity level.
All speeds are reduced to a low, but relatively uniform value. Freedom to
maneuver within the traffic stream is extremely difficult, and it is generally
accomplished by forcing a vehicle or pedestrian to "give way" to accommodate
such maneuvers. Comfort and convenience levels are extremely poor, and driver or
pedestrian frustration is generally high.
LOS "F" is used to define forced or breakdown flow. This condition
exists wherever the amount of traffic approaching a point exceeds the amount
which can traverse the point. Queues form behind such locations. Operations
within the queue are characterized by stop-and-go waves, and they are extremely
unstable. Vehicles may progress at reasonable speeds for several hundred feet or
more, then be required to stop in cyclic fashion. LOS "F" is used to describe
the operating conditions within the queue, as well as the point of the
breakdown.
For each type of facility, LOS is based on one or more operational parameters
which best describe operating quality for the subject facility type. The
parameters selected to define LOS for each facility type are called "Measures
Of Effectiveness" (MOE). For a 2 lane highway, the MOEs are "percent
time delay (%)" and "average travel speed (mph)". For a multilane highway, the
MOE is "Density (passenger cars/mile/lane)". For a signalized
intersection, the MOE is "average individual stopped delay (seconds/
vehicle)." For unsignalized intersections, the MOE is "Reserve capacity
(passenger cars/hour)."
For planning purposes, some engineers use the following uninterrupted flow
capacity (vehicles/day/lane) for the LOS indicated: "A" (2,500); "B" (4,000);
"C" (6,000); "D" (7,500); "E" (12,000).
To determine the operational capacity of a highway, engineers must
obtain detailed data based on the characteristics of a roadway. For a 2
lane highway, the data needed for an operational capacity analysis is:
terrain, lane width, shoulder width, "No Passing" zone, % Trucks, % RVs, % Buses
and directional distribution. For a multilane highway, the data needed
for an operational capacity analysis is: terrain, number of lanes, lane width,
lateral clearance, obstruction on 1 or 2 sides, highway type (divided or
undivided), suburban or rural, design speed, % Trucks, % RVs, % Buses and driver
population factor (based on regular users or non- regular users). Signalized
intersection analysis must consider the following prevailing conditions: the
amount and distribution of traffic movements, traffic composition, geometric
characteristics and the details of intersection signalization. Unsignalized
intersection analysis must consider the number and use of lanes,
channelization, % grade, curb radii and approach angle, sight distance and
average running speed on major roadway.
Each year for the last five years, there were more than 600 pedestrian
fatalities and over 7000 pedestrian injuries in Florida. 1985 Statistics
indicate a pedestrian fatality rate of 5.71 per 1000 population. Florida ranked
second in the nation for pedestrian fatalities with 655. California with 843
pedestrian fatalities was highest for that year. The major crash types most
often associated with pedestrian crashes are: Mid-block dartouts; Intersection
dash; Vehicle Turn/Merge; Multiple lanes crossing; Bus stop related; Vendor--Ice
Cream Truck and Backing Up .
Walk Defensively - Be prepared for the unexpected--don't let cars
surprise you even if a motorist does something wrong like running a stop sign or
making a sudden turn.
Walk Facing Oncoming Traffic - When there are no sidewalks, walk near
the curb, or off the road, if necessary.
Cross Streets at Intersections Whenever Possible - Look in all
directions before entering the street. Be especially alert to vehicles that
may be turning right on a red signal. If there are crosswalks, use them but
don't assume you are completely safe in a crosswalk. Don't cross at mid-block
because "jaywalking" is dangerous and against the law.
At Intersections, Look for the Signs or Signals - They will help to
cross safely. Use the push-buttons for crossing protection at signalized
intersections that have pedestrian indications. The lighted "Walk" and "Don't
Walk" signals are meant for the pedestrian. If the "Don't Walk" light is
blinking while you are in the street, continue quickly and carefully. If there
are no walk signals, watch the traffic signals. When there are only STOP or
YIELD signs, look in all directions and cross when traffic has cleared.
Be Careful in Parking Lots - Pedestrians are supposed to have the
right of way but many drivers don't wait for pedestrians. Parking lots can be as
dangerous as streets. On streets, the direction of cars is usually known but in
parking lots, cars might be moving in all directions, including backwards.
Avoid Dangerous Moves - Any movement a pedestrian makes that drivers
aren't expecting, could be dangerous. When leaving a school bus, wait a second
before crossing. Drivers don't always stop for unloading school buses; so stop,
look both ways and then cross. Don't step into traffic from between parked cars
since this is a sure way of surprising drivers.
Keep Your View of Traffic Clear at All Times - A pedestrian needs to
be able to see cars around him. Don't block your view with packages, umbrellas
or other objects.
After Dark, Wear Light Colored or White Clothes - Drivers can see you
better if you wear light colored or white clothes. Carry a lighted flashlight
and swing it back and forth to improve your chances of being seen by drivers. In
spite of the relatively small percentage of pedestrian travel during darkness,
more than one-third of pedestrian crashes occur during dark conditions.
Following all these tips while you are a pedestrian will greatly improve your
chances of safely walking your estimated lifetime average of 75,000
miles.
The Institute of Transportation Engineers, an international professional
organization, defines traffic engineering as "that phase of engineering
which deals with the planning, geometric design and traffic operations of roads,
streets and highways--their networks, terminals, abutting lands and
relationships with other modes of transportation--for the achievement of safe,
efficient and convenient movement of persons and goods."
When roads and streets were built many years ago, the biggest task facing the
road builder was to keep them passable in all types of weather. The problem of
moving large numbers of cars and parking them was not significant.
As the number of cars increases, taxing the capacity of our streets and
highways, the field of traffic engineering has become increasingly
prominent. Each year more people own and operate cars. Urban growth has
increased the need for public transportation, for improved movement of goods,
for new shopping and industrial centers, and for transportation terminals.
Funding for new roads has decreased, due partly to environmental concerns. This
has resulted in an increased emphasis on improving the existing road system as
much as possible. Traffic Engineering is helping to meet these challenges.
Traffic Engineering extends beyond the local level. It plays a vital role in
the functional design and traffic operations of the Interstate Highway System.
The Traffic Engineer must formulate recommendations for the integration of
freeways, shopping centers, and industrial complexes into communities which will
serve the population and benefit future development. Traffic Engineers design
and operate highway control and communication systems and devise ways to expand
capacity and improve safety of existing roads and streets.
Traffic Engineering involves two major areas of activity:
(1) team decision making about new streets, highways and other transportation
matters;
(2) responsibility for the efficient, convenient, and safe use of existing
transportation facilities.
The Traffic Engineer is concerned with groups and individuals and their
needs, desires, actions, characteristics, capabilities and limitations as
related to the roadway system. His decisions affect drivers, passengers, and
pedestrians.
One of the tasks of traffic engineering is long-range transportation
planning. Working with sophisticated, computer-aided techniques, engineers and
planners determine future transportation needs.
In Florida, speed limits are set by Florida Statutes, Chapter 316, which
deals with the "State Uniform Traffic Control".
Florida Statutes Chapter 316.187, authorizes the Florida Department of
Transportation (FDOT) to set maximum and minimum speed limits for travel on the
roadways under its authority as it deems safe and advisable, not to exceed 55
miles per hour, 65 mph on certain designated segments of interstate highways.
Florida Statutes, Chapter 316.189, presents the authority for establishment
of municipal and County speed zones maintained by these agencies. This section
indicates that the maximum speed on any Municipal or County maintained road is
30 mph. However, the Municipality or County may set speed zones altering such
speeds, both as to maximum and minimum after investigation determines such a
change is reasonable and in conformity with the criteria established by the
FDOT.
Traffic engineers throughout the country use the normal driver's speed as
a guide in setting speed limits since most drivers tend to regulate their own
speed according to traffic, road and weather conditions.
For a speed limit to be effective, at least 85 percent of the drivers must
voluntarily comply with the law. It is important to remember that the
speed regulation informs the driver of the limits in which one can safely
operate a vehicle under normal circumstances and within which the driver can be
expected to react safely. Setting speed limits at appropriate levels will create
a reasonable uniform flow of traffic, discourage violation of the law and help
keep streets and highways safe.
The FDOT criteria for setting speed zones are presented in the publication
entitled "Speed Zoning for Highways, Roads and Streets in Florida for Compliance
with the Florida Statutes, Chapter 316." This publication indicates "The 85th
percentile speed is the speed at or below which 85 percent of the observed free
flow vehicles are traveling." It also states that a speed limit should
not differ from the 85th percentile speed by more than 3 mph and it shall
not be more than 8 mph less.
The following excerpts were also taken from the FDOT Speed Zoning
publication:
"It is common traffic engineering knowledge that most drivers (about 85%)
travel at a reasonably safe speed for the various roadway conditions encountered
regardless of speed limit signs, but it is for those drivers who don't that the
practice of speed zoning does take place for the purpose of providing realistic
speed restrictions to which meaningful enforcement can be applied."
"The vehicle speed chosen by a driver is influenced by many factors: the
presence of other vehicles, weather, road conditions, road geometrics, adjacent
land use, and other factors tabulated in this report. A driver's choice of speed
is a balance between expediency and safety, and is often a subconscious reaction
to environment."
"Motorists tend to pay little attention to speed regulations which they
consider unreasonable unless there is an inordinate degree of enforcement."
"Unreasonably low speed limits are commonly violated by a majority of
motorists, making enforcement difficult, with resultant operating speeds
sometimes higher than would exist with proper, realistic speed limits."
Many variables affecting traffic generation make it difficult to predict the
precise amount of traffic to be generated by a project. However, transportation
studies have quantified, in general terms, the volume generated for different
types of land use. The Institute of Transportation Engineers (ITE) has compiled
a listing of trip generation rates for various land uses. These rates were
developed from studies conducted throughout the country. Trip Generation Rates
for residential land uses are usually expressed as average weekday vehicle Trip
Ends per Dwelling Unit (TE/DU) while those for commercial developments are
typically expressed as average weekday vehicle trip ends per 1,000 Gross Square
Feet of Leasable Area (KGSFLA), per 1,000 Square Feet of Gross Floor Area
(KSFGFA), per 1,000 Square Feet of Building Area (KSFBA) or per 1,000 Gross
Square Feet (KGSF). A "Trip End" is defined as a single or one-direction vehicle
movement, in or out of the site. The table below is a summary of trip generation
rates presented in the 1991 ITE publication entitled "Trip Generation - 5th
Edition."
AVERAGE RANGE STUDIES
RESIDENTIAL
Single Family Detached (210) 9.55 TE/DU 4.31-21.85 348
Apartment - General (220) 6.47 TE/DU 2.00-11.81 109
Low Rise Apartment (221) 6.59 TE/DU 5.10-9.24 22
High Rise Apartment (222) 4.20 TE/DU 3.00-6.45 9
Residential Condominium (230) 5.86 TE/DU 1.83-11.79 53
Mobile Home Park (240) 4.81 TE/DU 2.29-10.42 37
Recreational Home (260) 3.16 TE/DU 3.00-3.24 2
Residential Planned Unit Development (270) 7.44 TE/DU 5.79-14.38 12
RETAIL
Shopping Center (820):
10 KGSF 167.59 TE/KGSFLA ---
50 KGSF 91.65 TE/KGSFLA ---
100 KGSF 70.67 TE/KGSFLA ---
200 KGSF 54.50 TE/KGSFLA ---
300 KGSF 46.81 TE/KGSFLA ---
400 KGSF 42.02 TE/KGSFLA ---
500 KGSF 38.65 TE/KGSFLA ---
Specialty Retail Center (814) 40.67 TE/KGSFLA 21.30-50.94 3
Discount Store (815) 70.13 TE/KGSFLA 25.53-363.16 7
Restaurant-Quality (831) 2.86 TE/SEAT 1.77-5.50 12
Restaurant-Quality (831) 96.51 TE/KSFGFA 48.56-139.33 12
Restaurant-High Turnover Sit Down (832) 205.36 TE/KSFGFA 112.00-363.16 4
Restaurant-Fast Food w/Drive Thru (834) 632.12 TE/KSFGFA 284.00-1359.50 8
Convenience Market - 24 Hr Open (851) 737.99 TE/KGSF 330.00-1,438.00 8
OFFICE
General Office 10 KGSF (710) 24.60 TE/KGSF ---
General Office 50 KGSF (710) 16.58 TE/KGSF ---
General Office 100 KGSF (710) 14.03 TE/KGSF ---
Medical Office Building (720) 34.17 TE/KGSF 23.16-42.55 6
Government Office Building (730) 68.93 TE/KGSF -------- 1
U.S. Post Office (732) 87.12 TE/KSFGFA 35.57-352.42 6
Office Park (750) 11.42 TE/KSFGFA 7.56-30.30 12
SERVICE
Bank (Walk-In) (911) 140.61 TE/KGSF 134.60-156.48 2
Bank (Drive-In) (912) 265.21 TE/KGSF 150.86-817.00 14
Savings & Loan (Walk-In) (913) 61.00 TE/KGSF -------- 1
Savings & Loan (Drive-In) (914) 74.17 TE/KGSF -------- 1
LODGING
Hotel (310) 8.70 TE/Room 5.31-9.58 7
Motel (320) 10.19 TE/Occu.Rm 4.67-14.64 13
MEDICAL
Hospital (610) 11.77 TE/Bed 3.00-32.83 20
Hospital (610) 16.78 TE/KGSFA 11.40-45.14 14
Nursing Home (620) 2.60 TE/Bed 1.88-3.97 18
Clinic (630) 23.79 TE/KGSFA -------- 1
INDUSTRIAL
General Light Industrial (110) 6.97 TE/KGSF 1.58-16.88 18
General Heavy Industrial (120) 1.50 TE/KGSF 0.58-1.84 3
Industrial Park (130) 6.97 TE/KGSFBA 0.91-36.97 48
Manufacturing (140) 3.85 TE/KGSF 0.50-52.05 60
Warehousing (150) 4.88 TE/KGSF 1.51-17.00 15
WHY CAN'T WE HAVE A 4-WAY STOP TO REDUCE CRASHES?
Many people believe that installing STOP signs on all approaches to an
intersection will result in fewer crashes. This is not always the case, however.
Although the crash severity may be lessened, drivers are penalized by the
additional delay and higher vehicle operating costs (fuel, brakes, etc.). There
is no real evidence to indicate that STOP signs decrease the speed of traffic.
Impatient drivers view the additional delay caused by unwarranted STOP signs as
"lost time" to be made up by driving at higher speeds between STOP signs.
Unwarranted STOP signs breed disrespect by motorists who tend to ignore them or
slow down without stopping. This can sometimes lead to tragic consequences.
State Law requires the installation of all traffic control devices, including
STOP signs to meet State standards adopted by the Florida Department of
Transportation (FDOT). Florida Statutes, Section 316.0745, state: "The
Department of Transportation shall adopt a uniform system of traffic control
devices for use on the streets and highways of the State." The Statutes also
state: "All official traffic control signals or official traffic control devices
purchased and installed in this State by any public body or official shall
conform with the manual and specifications published by the Department of
Transportation ...."
The Manual on Uniform Traffic Control Devices (MUTCD) published by the
U.S. Department of Transportation is the national standard for Traffic Control
Devices. The FDOT has adopted the MUTCD as the State standard.
The installation of a multiway stop condition must first meet the warrants as
set forth in the MUTCD. Any of the following conditions may warrant a STOP sign
installation (sec. 2B-5):
1. Where traffic signals are warranted and urgently needed, the multiway STOP
is an interim measure that can be installed quickly to control traffic while
arrangements are being made for the signal installation.
2. A crash problem, as indicated by five or more reported crashes of a type
susceptible to correction by a multiway STOP installation in a 12-month period.
Such crashes include right and left-turn collisions as well as right-angle
collisions.
3. Minimum traffic volumes:
(a) The total vehicular volume entering the intersection from all approaches
must average at least 500 vehicles per hour for any 8 hours of an average day,
and
(b) The combined vehicular and pedestrian volume from the minor street or
highway must average at least 200 units per hour for the same 8 hours, with an
average delay to minor street vehicular traffic of at least 30 seconds per
vehicle during the maximum hour, but
(c) When the 85-percentile approach speed of the major street traffic exceeds
40 miles per hour, the minimum vehicular volume warrant is 70 percent of the
above requirements.
STOP signs should not be viewed as a cure-all for solving all safety problems
but, when properly located, can be useful traffic control devices to enhance
safety for all roadway users.
In 1972, the Florida Legislature enacted Chapter 380.06 of the Florida
Statutes. This law identified large developments for extensive review. These
Developments are called Developments of Regional Impact (DRI). Chapter 380.06
states that a project is considered to have a regional impact and designated a
DRI if because of its character, magnitude or location, it would have a
substantial effect on the health, safety or welfare of citizens of more than one
county. The law further specifies thresholds for different land use types that
will vary with the size of the county. The following list is a summary of
thresholds for various facilities:
AIRPORTS - Any new airport with paved runways, new passenger terminal
or existing runway or terminal expansion by 25% or more.
ATTRACTIONS & RECREATION FACILITIES - Any of the following
facilities:
1. Sports, entertainment, amusement or recreation facility which provides
for:
(a) a single performance with over 2,500 parking spaces or more than 10,000
permanent seats;
(b) a serial performance with over 1,000 parking spaces or more than 4,000
permanent seats.
2. Construction of a new pari-mutuel facility or an existing facility that
has a 10% increase in parking spaces.
HOSPITALS
1. A proposed hospital which has a design capacity of more than 600 beds, or
2. A new facility that serves two or more counties.
INDUSTRIAL PLANTS & INDUSTRIAL PARKS
1. Any new facility with over 2,500 parking spaces, or
2. A new facility that occupies a site greater than 320 acres.
MINING OPERATIONS
1. A facility with removal or disturbance of over 100 acres per year of solid
minerals or overburden, or
2. A facility with a water consumption of over 3,000,000 gallons per day.
OFFICE DEVELOPMENTS
1. A new facility that occupies over 30 acres of land, or
2. A facility with over 300,000 square feet of gross floor area.
3. A facility with over 600,000 square feet of gross floor area in counties
over 500,000 population.
PETROLEUM STORAGE FACILITIES
1. A new facility within 1,000 feet of navigable water and storing over
50,000 barrels, or
2. A new facility with a storage capacity of over 200,000 barrels.
PORT FACILITIES
1. Wet storage or mooring of over 100 watercraft used exclusively for sport,
pleasure or commercial fishing.
2. Dry storage of more than 150 watercraft used for sport, pleasure or
commercial fishing.
3. Wet or dry storage or mooring of more the 300 watercraft used exclusively
for sport, pleasure or commercial fishing in an area in the state marina siting
plan as suitable for a marina.
4. Dry storage of over 300 watercraft used exclusively for sport, pleasure or
commercial fishing at a marina constructed prior to 7-1-85.
RESIDENTIAL DEVELOPMENTS - Any proposed residential development to be
over the following dwelling units:
a) Counties with a population of less than 25,000, threshold = 250 welling
Units (DU's).
b) Counties with 25,000 to 50,000 population, threshold = 500 DU's.
c) Counties with population of 50,001 to 100,000, threshold = 750 DU's.
d) Counties with population of 100,001 to 250,000, threshold = 1,000 DU's.
e) Counties with population of 250,001 to 500,000, threshold = 2,000 DU's.
f) Counties with population of of over 500,000, threshold = 3,000 DU's.
SCHOOLS
1. A new school with over 3,000 full-time equivalent students, or
2. The expansion of a facility by at least 20% of the design population.
SHOPPING CENTERS - Any proposed retail or wholesale business that
1. Occupies more than 40 acres of land, or
2. Encompasses more than 400,000 square feet of gross floor area, or
3. Provides parking spaces for more than 2,500 cars.
HOTEL OR MOTELS -
1. Any proposed hotel or motel development that is planned to create or
accommodate 350 or more units, or
2. Any proposed hotel or motel development over 750 units in counties with
over 500,000 population.
RECREATIONAL VEHICLE DEVELOPMENTS - Proposed recreational vehicle
development with 500 or more spaces.
MIXED USE DEVELOPMENTS
Any proposed development with two or more land uses if the sum of the
threshold percentages is more than 130%.
The developer of any project exceeding 120% of these thresholds must file an
application for Development Approval with the State Department of Community
Affairs, the Regional Planning Council and the unit of local government having
jurisdiction. This application must include:
- Maps and a project description.
- Environmental information that covers air, land, water, wetlands, flood
plains, vegetation and wildlife.
- Historical and Archaeological sites.
- Employment and Economic Characteristics.
- Public Facilities including wastewater management, drainage, water supply,
solid waste, energy, education, recreation and open space, health care, police
and fire protection and public transportation.
- Housing.
If a development is between 80% and 120% of the above thresholds, the
developer may need to prove that it is not a DRI by preparing a "Binding Letter
Application" (BLA). The BLA, much simpler than a DRI, is a short form impact
assessment which is intended to show whether the developer's project has any
significant regional impact.
State and local governments have become aware of the costs of uncontrolled
growth. Inadequately managed development imposes costs in terms of additional
public facility and service needs, adverse environmental impacts, and a lot of
the qualities which make a community special. Florida's citizens and local
officials are beginning to recognize that properly managed growth can benefit
their communities in several ways. Potential benefits include a broader range of
job opportunities, protection of natural resources, affordable housing, the
elimination of sprawl and a more compact development pattern which is capable of
being served by existing and planned public facilities.
In response to this awareness, the Florida Legislature, during the past
fifteen years, has enacted a series of laws requiring state, regional and local
government agencies to prepare plans to manage Florida's rapid growth. A 1972
Act directed the Governor's Office to prepare a State Comprehensive Plan for
adoption by the Legislature and directed the eleven regional planning councils
to prepare and adopt comprehensive regional policy plans, all within specified
deadlines.
Local governments, which were required by a 1975 act to prepare and adopt
comprehensive plans, were directed by the 1985 and 1986 revisions of that act
(the Local Government Comprehensive Planning and Land Development Regulation
Act) to ensure that their plans were consistent with the State Comprehensive
Plan and appropriate regional plans. The result of this legislation is a
statewide framework for coordinated planning.
Because both the State Comprehensive Plan, adopted by state statute, and
local plans, which must be adopted by ordinance, have the force of law, this
framework does more than require the production of government documents. To
ensure that local plans are implemented, the local planning act directed the
state land planning agency (the Florida Department of Community Affairs) to
adopt by rule minimum criteria for determining plan compliance with the act and
required local plans to contain measurable objectives and specific policies to
ensure implementation. It also required local governments to adopt, within one
year after submitting their plan for state compliance review, specific land
development regulations consistent with their plan and to only allow development
where sufficient services are available or are committed to be available at the
same time as the development's impacts.
Regardless of where a local government chooses to begin planning, an initial
vision, subject to refinement later, can help guide other important planning
activities. These activities include the collection and analysis of data related
to locally perceived needs, the development of goals, objectives and policies to
achieve the desired future growth pattern and way of life, and the ongoing
evaluation of the plan's effectiveness in meeting local needs and achieving
desired results.
The Local Government Comprehensive Plan consists of the following elements:
Future Land Use; Traffic Circulation; Mass Transit; Port, Aviation and
Related Facilities; Housing; Sanitary Sewer, Solid Waste, Drainage, Potable
Water, and Natural Groundwater Aquifer Recharge; Coastal Management;
Conservation; Recreation and Open Space; Intergovernmental Coordination; and
Capital Improvements.
In 1977, the Florida Legislature enacted Chapter 77-165 which provided for
the establishment of the functional classification of public roads in Florida.
The law defined the various road classifications, established public road
systems based on these classifications and provided a mechanism for a continuing
evaluation of each classified road. The law also required that functional
evaluations performed after 1982 utilize a quantitative criteria developed
by the Florida Department of Transportation (FDOT).
Florida Statutes, Chapter 334.03, defines Functional Classification as
"The assignment of roads into systems according to the character of service they
provide in relation to the total road network. Basic functional categories
include arterial roads, collector roads and local roads which may be subdivided
into principal, major, or minor levels. Those levels may be additionally divided
into rural and urban categories." Functional classifications designated by the
FDOT include:
State Urban Extension Principal Arterial County Rural Minor Collector
State Intra Urban Principal Arterial County Urban Extension Minor Collector
State Rural Minor Arterial County Intra Urban Collector
State Urban Extension Minor Arterial County Local Road
State Intra Urban Minor Arterial Municipal Intra Urban Collector
County Intra Urban Minor Arterial Municipal Urban Collector
County Rural Major Collector Municipal Local Road
Average Daily Traffic (ADT); Length of Road (Miles); Trucks (Number of);
Access Factor (ADT/access points per mile); Intersections/Interchanges
(Number of);
Mobility (Number of Counties road is in); Speed (MPH); Traffic Signals;
Lanes; Divided/Undivided
The second classification theory is based on the concept that the
whole road network is comprised of system elements (routes) that
interconnect and link together the end points of transportation service.
System elements are each defined in terms of their operation within a
hierarchal order of service connections. A few typical relationships between
road linkage and functional classification are shown below:
LINKAGE FUNCTIONAL CLASSIFICATION
Bypass Around Urban Area w/Minor Arterial Termini Minor Arterial
Community-to-Other Community, or to Urbanized/Urban Major Collector
Rural-to-Urbanized/Urban or Community/Not
Arterial-to-Arterial Minor Collector
Within Community Local
Due to the rapid growth throughout Florida, many agencies must depend on
several funding methods to provide for new road projects. Revenue sources that
are being used by various agencies include the following:
A. DISCRETIONARY TAXES
1. Ad Valorem (Property) Tax - While allowing local governments to use
the ad valorem tax, the Constitution limits the millage rate to 10 mills for
County purposes, 10 mills for Municipal purposes and 10 mills for school
districts. Although additional ad valorem millage for debt service and operating
purposes for a maximum of two years is allowed, this additional millage is
subject to voter approval.
2. Municipal Utility Tax - This tax is available to municipalities up
to a maximum of 10%, with other statutory limitations depending upon the type of
utility being taxed.
3. Occupational License Taxes - Cities and Counties can use this tax.
B. NON-DISCRETIONARY TAXES
1. Sales Taxes for Mass Transit - At up to 1% rate, these taxes are
available to Broward, Dade, Duval, Sarasota and Volusia Counties.
2. Motor Fuel Tax - The 5th, 6th and 7th cent of the State
motor fuel tax is paid directly to Florida's 67 counties. Distribution is based
on 25% County area, 25% population and 50% motor fuel tax collection to the
total State. The 5th and 6th cent must be used for road construction and
maintenance and the 7th cent must be used for maintenance of County roads
and bridges.
A Local Option Motor Fuel Tax of up to 6 per gallon, earmarked for
transportation needs, can be levied without voter approval by all Counties and
an additional Voted motor fuel tax of 1 per gallon is allowed with voter
approval.
The Optional 6 per gallon Motor Fuel Tax that a County can assess must be
used for "transportation expenditures" including (a) Public transportation
operations and maintenance; (b) Roadway and right of way maintenance and
equipment; (c) Roadway and right of way drainage; (d) Streetlighting; (e)
Traffic signs, traffic engineering, signalization and pavement markings; (f)
Bridge maintenance and operation; (g) Debt service and current expenditures for
transportation capital projections in the foregoing program areas including
construction or reconstruction of roads.
The voted 1 per gallon tax pays the costs of land acquisition,
construction, reconstruction and maintenance of roads and streets.
3. Municipal/State Revenue Sharing is unit-based (i.e., cigarettes and
8th cent motor fuel tax).
4. County/State Revenue Sharing is largely based on the intangible
tax. Intangible tax is based on personal property such as stocks, bonds, mutual
funds and other obligations for payment of money.
5. User Fees are direct charges for products or services such as toll
roads.
6. Special Assessments may be used by counties, municipalities and
special districts for indirect service charges. The service must provide a real
and substantial benefit to real property. Special assessments differ in type or
degree from the benefits provided to the community as a whole.
7. Impact Fees fall under the category of an indirect charge for
services. Impact fees rely on the police power of the jurisdiction, not on any
taxing authority. They cannot be used for improvements to, or extensions of,
existing facilities unrelated to the needs created by new development, nor can
they be used for operation, maintenance or replacement of existing facilities.
They can only be used for those capital facility capacity needs necessitated by
new growth.
All existing Federal, State and local funds for roads have specific uses or
system limitations. Consequently, it becomes necessary to determine which system
receives improvements. With the estimate of funds by category, a financial plan
can be refined from the needed roadway improvements. By using the functional
classification program, certain roads are identified by ownership and are
eligible for funding on a priority basis.
Revised: March 23, 1990
A computer model is simply a representation of a real object or
process. Physical models are used to represent objects or structures.
Mathematical models are used to represent established relationships which
evolve from some process such as the interaction between speed, flow, and
density in a traffic stream. Computer models are mathematical rather than
physical in nature. The use of a mathematical model does not necessarily require
a computer; however, models that describe complex relationships or multiple
operations are usually easier to incorporate into a computer program than to
calculate manually.
There are two general approaches to numerical problem solving in
engineering.
1. The first is the experimental or empirical approach in which
answers to engineering questions are by actual measurement rather than by
calculations. For example, the traffic carrying capacity of a roadway has been
addressed experimentally to determine the effect of such factors as roadway
width, parking, etc. The results have been incorporated into the "Highway
Capacity Manual". The main advantage of the experimental approach is the
credHOWibility resulting from making direct measurements of a specific process
under specific conditions. There is no need to rely on assumptions,
approximations or other factors that may reduce confidence in the validity of
the solution to a given problem.
2. The modeling approach, on the other hand, makes use of available
information on the process being studied to generate additional information,
generally in the form of specific answers to specific questions. Compared to the
direct measurement approach, computer modeling offers some important benefits in
certain areas, especially when applied to complex problems which do not lend
themselves to simple experimental solutions. Specific advantages include:
(a) Cost: it is usually possible to model a complex situation such as
a moon landing at much lower expense,
(b) Safety: computer specialists are seldom injured in the course of
their duties,
(c) Speed: many processes such as weather patterns can be simulated at
many times their actual speed,
(d) Scope: it is possible using computer modeling to examine
hypothetical problems such as a proposed road or to develop future traffic
volumes,
(e) Controllability: it is usually easier to constrain the parameters
of a model; consequently, the effects of each parameter may be independently
controlled.
All of these advantages are of some interest to the traffic engineer who is
concerned with systems that are costly to install, which experience
safety problems, and which require data analysis over long periods
often under hypothetical conditions.
A few popular transportation models are:
SOAP (Signal Operations Analysis Package)
PASSER (Progression Analysis and Signal
System Evaluation Routine)
TRANSYT-7F (TRAffic Network StudY
Tool)
NETSIM (NETwork SIMulation Model)
FSUTMS (Florida Standard Urban
Transportation Model Structure)
FSUTMS stands for the Florida Standard Urban
Transportation Model Structure. This standard model has
been under development by the Florida Department of Transportation (FDOT) since
1975.
The FSUTMS model structure consists of standardized computer software; urban
area data formats and operating procedures. These standards common to all urban
studies in Florida, have been developed for the primary purpose of reducing the
time and effort required to produce long-range travel demand forecasts. Under
such standardization, FDOT is able to efficiently provide software updates,
procedural manuals, and technical support to district and local planning
agencies.
The FSUTMS model is available in micro, mini and mainframe versions that use
the same input data. In Florida at least 22 urban study areas have been modeled
using FSUTMS.
The following 6 basic program steps are identified in the Florida Standard
Model:
1. The External Trips Step data parameters include:
- Base Year external to external (EE) trip interchanges
- Growth Rates for each External station
- Ratio of through (EE) trips to internal-external (IE) trips at each
external station
2. The Trip Generation Step data parameters are:
- Trip Production and Attraction Rates
- Land Use Social Economic Variables
3A. The Highway Network Step data parameters include: 3B. The
Transit Network Step data parameters include:
- Coordinates (for distance calculations) - Transit Headway
- Toll Information - Transit Layover Time
- Number of Lanes - Transit Routes and Modes
- Area Type and Facility Type - Transit Operating Costs
- Speed and Capacity - Passenger Car Equivalents
- Traffic Counts
4. The Distribution Step data parameters include:
- Friction Factors
- Terminal and Intrazonal Times (Terminal times represent the trip
time utilized in traveling from the doorway at the trip origin to the vehicle at
its parked location. Intrazonal times account for travel time within a
zone.)
- Transit Captivity Factor and Utility Constants
5. The Mode Step (computes Mode Split, convert auto person trips to
auto vehicle trips)
- Mode Split Parameters
- Occupancy Rates
6. The Assignment Step data parameters include:
- Number of Iterations (should be set to maximize accuracy and minimize
computer time) full peak hour to 24 hours
- CONFAC factor (to convert hourly capacities to daily capacities)
- Speed change curve for capacity restraint
7. The Evaluation Step data parameters include:
- Crash rates
- Noise rates
- Emission rates
- Energy usage
- Capital Improvement Costs
- Maintenance Costs
- Travel Time Costs
- Crash Costs
Revised: April 1, 1989
In order to assure traffic signals are installed only where necessary, a
series of 11 warrants have been developed and accepted by traffic engineers
throughout the country.
Traffic signal warrants are contained in a manual developed by the U.S.
Department of Transportation, entitled "Manual on Uniform Traffic Control
Devices" (MUTCD).
For State approval, a signal must meet at least one of the warrants presented
in the MUTCD.
A summary of the 11 Warrants for Traffic Signals is presented in the
following table.
WARRANT MAJOR STREET (1) OF MINOR STREET (1)
(vehicles/hr for 8 hrs) (vehicles/hr for 8 hrs)
1. Minimum Vehicular Volume (depends on number of lanes) 500 to 600 150 to 200
2. Interruption of Continuous Traffic (depends on number of 750 to 900 75 to 100
lanes)
3. Minimum Pedestrian Volume 600 or more plus 150 or more
pedestrians crossing streets ---
4. School Crossing insufficient number of adequate
gaps to allow children to cross ---
5. Progressive Movement to maintain proper vehicle
grouping between successive ---
signals
6. Crash Experience five or more crashes susceptible
to correction by signal control
within a 12 month period ---
7. Systems - two major streets 800 ---
8. Combination of Warrants 80 percent of two of the first
three warrants ---
9. Four Hour Volumes see MUTCD graph see MUTCD graph
10. Peak Hour Delay see MUTCD graph see MUTCD graph
11. Peak Hour Volume see MUTCD graph see MUTCD graph
SOURCE: Adapted from Manual on Uniform Traffic Control Devices,
(MUTCD) 1978 by the U.S. Department of Transportation.
The "FDOT Greenbook" was developed by the Florida Department of
Transportation (FDOT) and is entitled "Manual of Uniform Minimum Standards for
Design, Construction and Maintenance of Streets and Highways."
The purpose of the FDOT Greenbook is to provide uniform minimum standards and
criteria for the design, construction and maintenance of all public streets,
roads, highways, bridges, sidewalks, curbs and curb ramps, crosswalks where
feasible, bicycle paths, underpasses and overpasses used by the public for
vehicular and pedestrian traffic as directed by Section 335.075 Florida
Statutes.
The FDOT standards are intended to provide the basic guidelines for
developing and maintaining a highway system with reasonable operating
characteristics and a minimum number of hazards.
The standards established by the FDOT Greenbook are intended for use on all
new construction projects. It is understood that the FDOT standards cannot be
applied completely to all reconstruction projects, however, the standards should
be applied to the extent that economic and environmental considerations and
existing development will allow.
When the FDOT Greenbook refers to guidelines and design standards given by
current American Association of State Highway and Transportation Officials
(formerly AASHTO) publications, these guidelines and standards should generally
be considered as minimum criteria.
The criteria and standards set forth in other Manuals which have been
included by reference shall be considered as requirements within the authority
of this Manual.
Listed below is a brief outline of the FDOT Greenbook.
A. Introduction A. Pavement Design
B. Conflicting Criteria B. Pavement Construction IX. BICYCLE FACILITIES
C. Highway Function and C. Shoulder Treatment
Classification
D. Operation D. Pavement Maintenance
X. MAINTENANCE
II. LAND DEVELOPMENT VI. ROADWAY LIGHTING A. Introduction
A. Introduction A. Introduction B. Objectives
B. Objectives B. Objectives C. Policy
C. Principles and Guidelines C. Warranting Conditions D. Identification of Needs
D. Conflict and Coordination D. Level of Illumination E. Establishment of Priorities
E. Control Techniques E. Uniformity of Illumination F. Establishment of Procedures
F. Reconstruction F. Underpasses G. Maintenance Program
G. Maintenance
III. GEOMETRIC DESIGN H. Light Poles XI. WORK SITE SAFETY
A. Introduction A. Introduction
B. Objectives VII. RAIL-HIGHWAY GRADE CROSSING B. Objectives
C. Design Elements A. Introduction C. Policy
B. Objectives and D. Planning of Operations
IV. ROADSIDE DESIGN C. Design and Grade Crossings E. Work Site Operations
A. Introduction D. Maintenance and Reconstruction F. Evaluation of Program
B. Policy
C. Objectives VIII. PEDESTRIAN TRAFFIC
D. Roadside Design A. Introduction
E. Protective Devices B. Policy and Objectives
C. Conflict Elimination & Reduction
D. Protection
Concurrency means that the necessary public facilities and services to
maintain the adopted level of service standards are available or will be in
place when the impacts of the development occur.
The "Local Government Comprehensive Planning and Land Development Regulation
Act", commonly referred to as the 1985 Growth Management Act (GMA), prohibits
the issuance of building permits to developments which would reduce the level of
public services impacted by the development to below the Level of Service (LOS)
required by a Local Government's Comprehensive Plan (LGCP).
Some have referred to the "Concurrency Doctrine" as the "Doomsday Clause" in
the Growth Management Act since it could severely limit or stop growth in parts
of the State.
Florida Statutes Section 163.3177(10)h(1987) state: "It is the intent of the
Legislature that public facilities and services needed to support development
shall be available concurrent with the impacts of such development. In meeting
this intent, public facility and service availability shall be deemed sufficient
if the public facilities and services for a development are phased, or the
development is phased, so that the public facilities and those related services
which are deemed necessary by the local government to operate the facilities
necessitated by that development are available concurrent with the
impacts of the development. The public facilities and services, unless already
available, are to be consistent with the capital improvement element of the
local comprehensive plan..."
The Act requires that each local government prepare a comprehensive plan and
submit its plan to Florida's State land planning agency, the Department of
Community Affairs (DCA), on designated dates between July 1, 1988 and July 1,
1991.
Florida Statutes, Section 163.3202(1)-(2)g(1987) require that: "(1) Within 1
year after submission of its...comprehensive plan (all local governments) in
this state shall adopt or amend and enforce land development regulations that
are consistent with and implement their adopted comprehensive plan...(2) Local
land development regulations shall contain specific and detailed provisions
necessary or desirable to implement the adopted comprehensive plan and shall as
a minimum: (g) Provide that public facilities and services meet or exceed the
standards established in the capital improvements element required (under this
Act) and are available when needed for the development, or that development
orders and permits are conditioned on the availability of these public
facilities and services necessary to serve the proposed development. Not later
than 1 year after its due date established by the state...a local government
shall not issue a development order or permit which results in a reduction in
the level of services for the affected public facilities below the level of
services provided in the comprehensive plan of the local government."
DCA's secretary, Thomas Pelham, has indicated the following will satisfy the
concurrency requirement: "(1) The necessary facilities are in place at the time
a development permit is issued or development permit is issued subject to the
condition that the necessary facilities will be in place when the impacts of the
development occur; (2) The necessary facilities are under construction at the
time a permit is issued; (3) The necessary facilities are the subject of a
binding contract executed for the construction of those facilities at the time a
development permit is issued; or (4) The necessary facilities have been included
in the local government's budget at the time a development permit is issued even
though the facilities are not yet the subject of a binding contract for their
construction."
Florida Statutes, Section 163.3215 (1987) provides that any aggrieved or
adversely affected party has the right to maintain action for injunctive or
other relief against any local government to prevent the local government from
taking any action on a development order that is not consistent with its adopted
comprehensive plan.
Land use activities generate traffic to and from a particular site. Many
types of commercial activities such as Service Stations, Fast Food Restaurants,
Convenience Stores, Supermarkets, Banks and Shopping Centers generate a portion
of the traffic that is already on the adjacent street that merely stop at the
establishment in passing by (i.e. passer-by traffic).
Passer-by factors are used to recognize and reduce the estimated additional
total daily traffic to the street(s) serving a proposed development. They are
not applied directly to reduce trip generation and turning movement volume at
driveways serving a development.
There are three categories of trips: Primary Shopping Trips, Diverted
Linked Trips and Passer-by Trips.
A Primary Shopping Trip to a retail facility is one in which the
purpose of the trip is shopping and the trip pattern is generally
home-to-shopping-to-home.
A Diverted Linked Trip or a Passer-by Trip is one in which the
shopping destination is a secondary part of the primary trip such as
work-to-shopping-to-home. The diverted linked trip involves a route diversion
from one roadway to another.
The Passer-by Trip comes directly from the traffic stream passing the
facility on the adjacent street system and does not require a diversion from
another roadway. Two ITE publications, the Trip Generation Manual, 5th Edition
(1991), and the Transportation and Land Development Manual (1988), present the
following data related to passer-by trip rates:
Service Station 58%
Fast-Food Restaurant 45%
Convenience Store 16-45%
Supermarket 28%
Banks w/Drive Thru Window 14%
Hardware Store 8%
Shopping Center:
Ln (Pass-By Trip %) = -0.341 Ln GLA
( )
1000
(Use with caution - See Manual)
50,000 SFGLA 56.94%
100,000 SFGLA 44.95%
150,000 SFGLA 39.15%
200,000 SFGLA 35.49%
250,000 SFGLA 32.89%
% Passer-by for Shopping Centers = 45.1 - 0.0225 X SFGLA/1000
The Florida Department of Transportation (FDOT) "Manual of Uniform Minimum
Standards For Design, Construction and Maintenance For Streets and Highways"
defines a "design vehicle" as a selected motor vehicle whose weight, dimensions
and operating characteristics are used to establish highway design controls to
accommodate vehicles of a designated type. For the purpose of geometric design,
the design vehicle should be one with dimensions and minimum turning radii
larger than those of almost all vehicles in its class. One or more of these
vehicles should be used as a control in the selection of geometric design
elements. In certain industrial (or other) areas, special service vehicles may
have to be considered in the design. Fire equipment and emergency vehicles
should have reasonable access to all areas.
If a significant number or percentage (5 percent of all the total traffic) of
vehicles of those classes larger than passenger vehicles are likely to use a
particular street or highway, that class should be used as a design control. The
design of major arterial streets and highways should normally be adequate to
accommodate all design vehicles. The decision as to which of the design vehicles
(or other special vehicles) should be used as a control is complex and requires
careful study. Each situation must be evaluated individually to arrive at a
reasonable estimate of the type and volume of expected traffic.
Design criteria that are significantly affected by the type of vehicle
include: horizontal and vertical clearances, alignments, lane widening on
curves, shoulder width requirements, turning roadway and intersection radii,
intersection sight distance and acceleration criteria. Particular care should be
taken in establishing the radii at intersections so that vehicles may enter the
street or highway without encroaching upon adjacent travel lanes or leaving the
pavement.
The American Association of State and Highway Transportation Officials
(AASHTO) manual entitled "A Policy On Geometric Design Of Highways and
Streets" indicates that the boundaries of the turning paths of ten selected
design vehicles when making the sharpest turns are established by the outer
trace of the front overhang and the path of the inner rear wheel. This turn
assumes that the outer front wheel follows the circular arc defining the minimum
turning radius as determined by the vehicle steering mechanism.
Geometric design requirements for trucks and buses are much more severe than
they are for passenger vehicles. Trucks and buses are wider and have longer
wheelbases and greater minimum turning radii. These are the principal
characteristic dimensions affecting horizontal highway design. The longer
single-unit trucks and buses require greater minimum turning radii than most
vehicle combinations, but because of their greater offtracking, the longer
vehicle combinations also require greater widths of turning paths.
The minimum turning radii of the outside and inside wheel paths shown are for
turns at less than 10 mph. Higher speeds require larger radii than the minimums.
(Note: The design table is on the next page.)
Traffic Engineers are striving to provide roadway conditions that contribute
to smooth and efficient traffic flow. Experience has shown that safety is
enhanced by smooth traffic flow. Disrupting the smooth flow of traffic increases
the probability of crashes.
Erratic traffic operation may be caused by vehicles stopping or slowing in
the roadway, passing and weaving maneuvers, unwarranted traffic signals, the
lack of street name signs and unreasonably low speed limits. In addition, too
many commercial signs may cause driver confusion and indecision. Slower speed
does not insure safer traffic operation. The chances of a driver becoming
involved in a crash are least when he is traveling at the average speed of
traffic. The population growth in many areas poses great challenges for Traffic
Engineers. These engineers are utilizing many traffic management techniques to
control traffic within the development review process. These management
techniques should:
Limit the number of driveways from new developments.
Increase spacing between driveways.
Limit indiscriminate access to major roads by requiring connecting drives
between adjacent shopping centers.
Require developers to direct traffic into signalized access points.
Require developers to provide a good turning radius at driveways to allow
drivers to enter and exit roads easily.
Require developers to provide tapers or turn lanes when needed.
Require developers to provide traffic control devices such as signs, pavement
markings and signals.
In addition, Traffic Engineers can improve traffic safety and congestion by
the following techniques:
Install computerized signal systems to improve traffic flow.
Install turn lanes at existing or proposed intersections and along
sections of roadways where there are frequent turning movements.
Install bikeways and sidewalks where needed.
Promote mass transit where feasible.
Promote ride share programs.
Direct benefits to the public can be improved safety and air quality and
reduced travel cost and travel time. Safety can be enhanced by improving
the uniformity of traffic flow and reducing the vehicles on the roadway. Air
Quality can be improved by reducing the number of stops and motorized
vehicles on the road. Delay in Travel Time can be reduced especially at
signalized intersections. Travel Cost can be reduced by minimizing delays
at traffic signals and in heavy traffic congestion.
HOW CAN I OBTAIN THE PUBLICATIONS USED BY TRAFFIC ENGINEERS?
Some of the Publications used by Traffic Engineers are listed below:
"Manual Of Uniform Minimum Standards For Design, Construction, and
Maintenance For Streets and Highways" (FDOT Green Book) 1994 Edition by
Florida Department of Transportation
Cost $10.00 + tax:
Florida Department of Transportation
Maps and Publications Section
Haydon Burns Building
605 Suwannee Street, MS-12
Tallahassee, Florida 32399-0450, Phone: (904) 488-9220 SUNCOM 278-9220
______________________________________________________________________________
"Manual On Uniform Traffic Control Devices For Streets and Highways"
(MUTCD) 1988 by the U.S. Department of Transportation. Publication Code LP-140
Cost $44.00 + 10% for Shipping & Handling with a $5 Minimum
Institute of Transportation Engineers
525 School Street, S.W.Suite 410
Washington, D.C. 20024-2729, Phone: (202) 554-805 * now a two book set *
______________________________________________________________________________
"A Policy On Geometric Design Of Highways and Streets, 1994" (includes
metric) (AASHTO Green Book) Publications Code GDHS
Cost $50.00 includes S/H:
American Association of State Highway and Transportation Officials
444 North Capitol Street N.W., Suite 249
Washington, D.C. 20001, Phone: (202) 624-5800
______________________________________________________________________________
"Highway Capacity Manual (Special Report 209), 1985" w/updated
chapters By Transportation Research Board. Publication Code LP-102
Cost $80.00 + 10% for Shipping & Handling with a $5 Minimum:
Institute of Transportation Engineers
525 School Street, S.W., Suite 410
Washington, D.C. 20024-2729, Phone: (202) 554-8050
______________________________________________________________________________
"Trip Generation Manual (5th Ed)" 1991 by Institute of Transportation
Engineers. Publication Code IR-016A
Cost $150.00 ($130.00 to ITE Members) + 10% for Shipping & Handling:
Institute of Transportation Engineers
525 School Street, S.W., Suite 410
Washington, D.C. 20024-2729, Phone: (202) 554-8050
______________________________________________________________________________
"Florida Traffic Laws - Florida Statutes 1987 - Chapter 316 State Uniform
Traffic Control" No Charge from: $10.60 prepaid, includes S/H
Department of State
Bureau of Administrative Code
401 S. Monroe St.
Elliot Bldg.
Tallahassee, FL 32399-0250
A "closed loop system" is a system of communication between individual
signalized intersections within an arterial or a network of arterial roadways,
and the Traffic Engineer.
A closed loop system basically consists of sampling detectors at
intersections, local controllers, one or more on-street master controllers and a
central microcomputer.
The system is called "closed loop" because two-way
communication can be maintained between the street controllers and the user.
"Open loop" systems maintain only one-way communication "up" from
the sampling detectors to the on-street master to the local controllers, but no
feedback is received from the local controller or the master. The addition of
the central microcomputer "closed the loop" in the system's communications. Data
is transferred from the sampling detectors to the master via the local
controllers; the sampling detectors report to the central microcomputer via the
master; and the central microcomputer transmits information to the master and to
the local controllers via the master.
ta Loading
The following data is entered by the microcomputer user via a keyboard:
Controller settings such as minimum and maximum GREEN, YELLOW, and RED times
System timing parameters such as cycle lengths, offsets, splits and
permissive periods
Traffic responsive computation information such as sampling detector
ththreshold values, detector assignments and weighting factors
Time clock information (at the master and local controllers) and Time Of Day
(TOD) and Day Of Week (DOW) schedule entries
The microcomputer "downloads" the above data to the master controller and to
each local controller via the master.
System Monitoring and Reports
The central microcomputer can receive from the master the following
information:
Mode of operation (TOD/DOW, traffic responsive, free, etc.) for the current
time and/or previous 24 hour period.
Timing plan in effect for the current time and the previous 24 hour period.
Status of local controllers (flash, preemption, failures, etc.) for the
previous 24 hours.
Status of sampling detectors (in/out service, failures) including all volume
and occupancy data for the previous 24 hours.
Increasing urbanization has made necessary many roadway reconstruction
projects in built-up areas. Some residents do not understand that the public
right of way extends into what they consider to be their private property.
The Florida Department of Transportation (FDOT) publication entitled "Manual
of Uniform Minimum Standards For Design, Construction and Maintenance For
Streets and Highways" (Green Book) includes the following definition of the term
"right of way": "A general term denoting land, property or interest therein,
usually in a strip, acquired for or devoted to transportation purposes. More
specifically, land in which the State, the Department, a County or a
municipality owns the fee, or has an easement devoted to or required for use as
a public road."
During roadway construction projects, many public agency officials or
contractors are mistakenly blamed for trespassing onto private property. Even if
the public agency does not own actual fee simple title to property, it may
acquire the right to the property when the public agency has maintained a
roadway for a period of at least four (4) years. This type of right of way is
known as prescriptive right of way.
Florida Statutes, Section 95.361, presents information on when roads are
presumed to be dedicated through the prescriptive right concept. This section
states: "When a road, constructed by a County, a municipality, or the Division
of Road Operations has been maintained or repaired continuously and without
interruption for 4 years by the County, municipality, or Division of Road
Operations, jointly or severally, the road shall be deemed to be dedicated to
the public to the extent in width that has been actually maintained for the
prescribed period, whether the road has been formally established as a public
highway or not."
Most public agencies such as Volusia County require a permit for any work
within the County right of way. This includes driveway connections and
culvert/utility installations. The reason for controlling work within the public
right of way is to insure that hazardous objects are not installed too close to
the roadway. Also, the maintaining agency officials must insure that
installations in the right of way do not obstruct the view of drivers.
The area of public right of way for roads usually varies from 50 feet for a
local road with curb and gutter to 300 feet for an interstate highway. To
determine the right of way width for a road, a citizen may contact the
Engineering Department (Right of Way Section) of the maintaining agency of the
roadway.
The term "GIS" is used to refer to Geographic Information
System. The computerized GIS is used to automate everything from simple
mapping functions to complex land use analysis, site selection and network
modeling.
GIS has created a new dimension in map making which allows an enhanced
ability to manage our cities, natural resources, parcels of land and utility
systems.
Using GIS, public officials can quickly evaluate the impact of proposed
facilities. For example, public works engineers can assess the impact of a
pollution spill on all areas along a water distribution path and fire and police
departments can dispatch vehicles based on a detailed analysis of the quickest
path between two points. Tasks that once took months can now be accomplished in
a few minutes, using GIS.
Through GIS, geographic information from maps, aerial photographs and batches
of descriptive records are fed into computers as overlays representing property
parcels, political and man-made boundaries, utility distribution networks,
natural land base features, land use patterns, demographic data, etc. This
information is tied to these graphic pictures by the numerous records that
describe them. For example, the dimensions and ownership data associated with
each land parcel, or the height, diameter, material, number and other
information associated with a utility pole. An urban planner could quickly find
all industrially zoned land that meets minimum acreage criteria and is within
100 yards of a major transportation feeder. GIS provides the means to point to a
parcel on a display screen and have instant access to all publicly available
information about that address.
A technology similar to GIS, is called AM/FM which is an acronym for
Automated Mapping/Facilities Management. GIS is used
within a planning, natural resources and land records management environment
AM/FM is used more often by the utility environment. The AM/FM stems from an
evolution of computer-aided drafting technology.
The basic hardware components of a GIS include:
Central Processing Unit (CPU) is where the information processing
tasks are performed and software commands executed.
Disk Drives are the storage medium for the GIS database. Tape drives
are the medium for loading data from other systems, backing up and storing GIS
data.
Output Devices include printers, plotters and copiers.
Digitizing Device is the mechanism for electronically tracing manually
produced maps to produce a digital version of the information.
Workstation includes a graphics display screen and a keyboard used for
data input, editing and manipulation.
BE PLACED AT AN INTERSECTION?
In Florida, as in most states, the standard for signs, signals and pavement
markings is the "Manual On Uniform Traffic Control Devices" (MUTCD). This
publication by the U.S. Department of Transportation serves as the standard for
the installation of all traffic control devices.
The MUTCD indicates that a stop bar (line) is a solid white line, normally 12
to 24 inches wide, extending across all approach lanes to a STOP sign or traffic
signal. A stop bar should be placed parallel to the centerline of the
intersecting street. A stop bar should be used in both rural and urban areas
where it is important to indicate the point, behind which vehicles are
required to stop, in compliance with a STOP sign, traffic signal, officer's
direction, or other legal requirement.
A stop bar, when used, should ordinarily be placed 4 feet in advance of and
parallel to the nearest crosswalk line. In the absence of a marked crosswalk,
the stop bar should be placed at the desired stopping point and no case
more than 30 feet or less than 4 feet from the nearest edge of the intersecting
roadway.
When a stop bar is used in conjunction with a STOP sign, it should be placed
in line with the STOP sign. However, if the STOP sign cannot be located exactly
where vehicles are expected to stop, the stop bar should be placed at the
desired stopping point.
In general, a STOP sign should be located to optimize nighttime visibility
and minimize mud splatter. In addition,a STOP sign should be located so that it
is not obscured by other signs or hidden from view by roadside objects and
vegetation.
In order to provide adequate lateral clearance for the motorists who may
leave the roadway in rural areas and strike the sign support, a STOP sign should
be located at least 6 feet from the edge of the shoulder or, if there is no
shoulder, 12 feet, with a maximum of 14 feet from the edge of the travelled way.
The height to the bottom of the STOP sign in rural areas should not be less than
5 feet or more than 8 feet above the edge of the roadway.
In urban areas a lesser lateral clearance may be used where necessary.
Although 2 feet is recommended as a working minimum, a clearance of 1 foot from
the curb face is permissible where sidewalk width is limited or where existing
poles are close to the curb. The height to the bottom of a STOP sign in urban
areas should not be less than 7 feet or more than 8 feet above the top of the
curb.
The following factors must be considered by Traffic Engineers and Planners in
order to develop traffic projections.
Historic traffic volumes
Historic and projected population growth rates
Future land uses, to include average expected development as well as
high impact developments (DRIs)
To determine future traffic projections, Engineers and Planners must:
Use data from an area transportation model, or
Use historic traffic counts and land use information to develop a
growth curve, or
Use historic traffic counts and a compound linear rate table to
determine a growth factor that is adjusted by changes in land
development.
Projection of future traffic volumes expected on the area roadways can be
accomplished using several methodologies, depending upon what data is available.
The use of an area transportation model, such as FSUTMS, is the
most desirable method. It assigns traffic to the roadway links based on a
comprehensive and complex series of vehicle trip assignments derived from
information on future population, economic conditions, land use and system
operations information.
An alternative analysis involves the use of growth trends developed
from historic traffic count information and land uses, both existing and
planned, for the area. This information, plotted over time, will form a curve
which is then extended to project future traffic volumes. Typically, the curves
will show a linear or non-linear relationship that should correlate with the
area's growth trends, i.e. high growth, slow but steady, increment, etc., each
of which should exhibit a different curve. Extension of the curve, consistent
with the expected growth trend, will provide future traffic volumes expected on
the roadways. This may be done by physically graphing the data or through the
use of computerized curve-fitting analysis programs. Knowledge of the area,
professional judgment, and economic conditions form important elements in
determining the rational basis for traffic projections.
Another methodology involves the use of growth factors referenced through
compound linear rate tables. This involves the determination of a rate of
growth from the ratio of the most recent and earliest count volumes, which is
then located on compound linear rate tables according to the number of years
between the counts. From this table, a growth factor is determined for the
desired number of years into the future, which is then applied to existing
traffic volumes to produce the expected traffic volume for the desired year. Any
anticipated major changes in land use could be used to alter the projection.
In order to insure multiway stop signs are installed only where necessary,
warrants have been developed by the U.S. Department of Transportation and
accepted by traffic engineers throughout the country.
The "Manual on Uniform Traffic Control Devices" (MUTCD) describes the
conditions that may warrant a multiway stop sign installation. Multiway stop
signs should only be used when traffic volumes on intersecting roads are
approximately equal.
ALL APPROACHES MINOR STREET
Average Vehicles/ Vehicles/Hr. +
Hr. for the Pedestrians/Hr.
WARRANT Highest 8 Hrs. during same
8 hours
1. At intersections where - -
traffic signals are
already warranted prior
to actual signal
installation
2. 5 or more crashes - -
(Right turn, left turn,
right angle) in a
12 month period
3. Minimum traffic volumes 500 200 + 30 sec./
vehicle delay
during maximum
hour
4. When 85 percentile speeds 350 140 + 30 sec./
exceed 40 MPH the minimum vehicle delay
traffic volume warrant is during maximum
70% of the normal warrant hour
Source: Adapted from Manual on Uniform Traffic Control Devices,
(MUTCD) 1988 by U.S. Department of Transportation.
The "Accessibility Requirements Manual" is a public document that was
published in January 1990 by the Department of Community Affairs (DCA), Florida
Board of Building Codes and Standards.
The 1989 Florida Legislature passed a bill which mandated many changes to the
requirements for accessibility for the physically handicapped. The bill also
stipulated that the Department of Community Affairs (DCA) be required to prepare
a manual which fully explains the relationship and requirements of the American
National Standards Institute standard and Part V of Chapter 553, Florida
Statutes relating to handicapped accessibility.
This manual was published by the Department of Community Affairs in
association with the Florida Agricultural and Mechanical University's Institute
for Building Sciences, School of Architecture, who illustrated the drawings and
cover.
Many different groups throughout the state including building departments,
design professionals, builders and handicapped advocates will use this
publication to determine the minimum requirements for providing accessibility.
Included in the manual are the requirements of Part V, Chapter 553, Florida
Statutes; the mandatory portions of A117.1, 1986; definitions; interpretive
illustrations; special notes; and an appendix of legislation relating to issues
that affect the disabled. The text is laid out in concert with the interpretive
illustrations so that a verbal and graphic representation of the subject matter
is presented together. It should be noted that the interpretive illustrations
are often construed as the code itself.
The code and manual address accessibility features designed for the
physically handicapped adult. It does not address the special needs of the
physically handicapped child; however, the Florida Department of Education is
currently developing a standard that identifies the special design requirements
needed to provide accessibility for physically handicapped children.
Accessibility features of buildings and facilities provide the opportunity
for handicapped persons in the community to become more self reliant and
independent. Barrier free design can help to enable a person with disabilities
to achieve his or her potential for contributions to our society.
The new DCA "Accessibility Requirements Manual" includes the following
topics:
Basic Components Windows Lavatories, Sinks, & Mirrors Signage
Space Allowances & Reach Ranges Doors Bathtubs Telephones
Accessible Route Entrances Shower Stalls Food & Liquor Service
Walkways Drinking Fountains Toilet Rooms, Bathrooms, Bathing Establishments
Protruding Objects & Water Coolers Facilities & Shower Rooms Seating,
Tables &
Ground & Floor Surfaces Restroom Vestibules Changing Rooms Work Surfaces
Parking Spaces & Passenger Restroom & Toilet Storage Areas Auditorium
& Assembly
Curb Ramps Grab Bars, & Tub & Loading Zones Room Clear Passage
Ramps Shower Seats Controls & Operating Mechanisms Residential
Stairs Water Closets Alarms Occupancies
Elevators Toilet Stalls Detectable Warnings Modifications &
Exceptions From Accessibility Urinals Enforcement & Date Waivers
Requirements
A copy of the DCA "Accessibility Requirements Manual" may be obtained from
the:
Department of Community Affairs
Florida Board of Building Codes & Standards
2740 Centerview Drive
Tallahassee, Florida 32399-2100
Phone: (904) 487-1824 SUNCOM 277-1824
When doing a traffic impact study, there is always the question as to how far
the study area should reasonably go from the site. The purpose of this TIPS is
to provide a general guidance for the study area radii for a particular type of
development.
These suggested study area radii require the consideration of two variables.
One of these is the type of land use, and the second is the magnitude of that
land use. The table below for suggested impact study area radii is based upon
the average trip length for various types of land uses. Generally, one quarter
of this average trip length is utilized as the significant impact area for the
largest developments for each type of land use and the study area decreases in
size with smaller projects. In rural areas the study area radii may be extended
to cover the nearest major intersections.
Average
Trip
Length Over 1000 500-1000 250-499 0-249
(Miles) Units Units Units Units
Residential 6-8 2.0 1.5 1.0 0.5
Hotel/Motel 2-3 1.5 1.0 0.5 0.25
Over 200,000 100,000-
GBA 199,000 0-99,000
Office 5-6 1.5 1.0 0.5
Over 400,000 200,000- 100,000- 50,000-
GBA 399,000 199,000 99,000 0-49,000
Shopping Center 1-5 1.5 1.0 0.75 0.5 0.25
All Sizes
Quality/Sit Down
Restaurant 1-1.5 0.25
Fast Food 0.5-1.0 0.25
Convenience
Store 0.5-1.0 0.25
Drive-In Bank 1.5-2.0 0.25
Day Care Center 1.5-2.0 0.25
Building
Materials 3.4 0.75
Over
1,000,000 500,000- 250,000-
GBA 1,000,000 499,000 0-250,000
Industrial/
Manufacturing 6-8 2 1.5 1 0.5
Traffic Control Devices (TCD's) such as Traffic Signals, Stop Signs and Speed
Limit Signs are installed to regulate traffic flow and improve safety. The
installation of these TCD's should be based on the professional judgement of
Traffic Engineers after careful study of the location to be controlled. The
study should consider such factors as crash frequency and type, vehicle speeds
and traffic volumes.
On occasion, an elected official, with a true "politician's" zeal to please
everyone, influences the installation of a traffic control device against the
advice of the Traffic Engineer. The elected official's motivation is often an
angry or persistent citizen rather than the objective professional judgement of
the Traffic Engineer.
Many elected officials do not realize that there are National guidelines for
the installation of Traffic Control Devices. The Manual On Uniform Traffic
Control Devices (MUTCD) gives Transportation Engineers the uniform standards to
safely assist motorists as they travel. It defines a series of uniform Traffic
Control Devices (Signals, Signs and Pavement Markings) which are clear in their
messages as applied on the nation's roadway system.
The March 1990 issue of "Public Roads" magazine, published by the U.S.
Department of Transportation, contained an article on "Motorist Compliance With
Standard Traffic Control Devices." The article examined the following forms of
motorist noncompliance:
Speeding
Not coming to a full stop at STOP signs
Failing to yield right of way to pedestrians
Ignoring active railroad crossing devices
Making illegal turns
Using lanes improperly
Violating traffic signal indications
Driving too fast through work zones
Encroaching on centerlines
Violating passing zone restrictions
The behavioral studies collected compliance and other data at a large number
of typical sites over extended periods of time. In the process, hundreds of
thousands of motorists were observed. The clear conclusion was that motorist
noncompliance does take place.
One of the recommendations in the US DOT article was: "To ensure that the
motoring public maintains a healthy respect for TCD's, traffic professionals
must use them prudently. Through concerted efforts of the nature outlined above
(Engineering, Enforcement and Education), the safety and efficiency of our
streets and highways can be maximized."
Another recommendation was to "Apply TCD's consistently to ensure they
command respect."
Landscape design is important because it can contribute greatly to safe
ingress and egress of any busy parking lot.
The problem begins long before the sight obstruction becomes noticeable to
the motorist. It starts when the architect and site planners are preparing
building plans and parking lot layouts. Many times the architect or site plan
designer will try to take advantage of the end island treatment of parking
aisles to meet landscaping requirements of the municipalities. Unfortunately,
the type of planting selected is not always functional from a traffic or
pedestrian safety perspective. When plants are allowed to grow to a height that
makes it difficult for a motorist to see oncoming vehicles or pedestrians, it
creates a traffic safety hazard.
Property owners, site managers and ground maintenance personnel should be
trained to identify poorly maintained plantings and correct hazardous
conditions. Property owners who invite the public onto their property should
come under the same scrutiny as the public sector.
Traffic crashes caused by sight distance problems in parking lots of shopping
center, office complexes or other private commercial sites are just as harmful
as traffic crashes on public residential streets. There could be more
pedestrians crossing in a neighborhood shopping center than on a typical
residential street.
Many traffic crashes on private sites go unreported because they are minor in
nature and many police departments do not respond to private property crashes
unless there is an injury. Pedestrian crashes from either public or private
sites are usually reported. Police agencies have very little enforcement
authority within private parking areas.
Because there is little documented traffic data on private property, traffic
analysts rely on judgment and experience when reviewing site plans from a
traffic safety perspective.
Municipalities have corner clearance ordinances regulating the height of
fences and hedges at the intersection of public roads. These restrictions are
generally enforced when the obstruction becomes a traffic safety problem.
However, there are few municipalities which have regulations or inspect sight
triangle or corner clearance obstructions in parking areas.
Good landscaping treatment that would improve safety and reduce crashes
should use the following guidelines:
1. Trees, at maturity, should not have a trunk diameter larger than 4 inches.
2. Trees should require very little trimming or other maintenance and should
not have branches lower than 6 feet.
3. Hedges should be avoided. Plants and vegetation should be no higher than
18 inches.
4. A clear zone between 18 inches and 6 feet above the ground should be left
open.
These few guidelines could go a long way toward reducing crashes within
private property parking areas. People bruise, bleed and break bones the same
way on public or private property - the ownership of the property does not
lessen the pain of the injured.
The Florida Department of Transportation states "The roadside clear zone is
that area outside the traveled way, available for use by errant vehicles." The
roadside clear zone is an area in the median or on the side of the road, off the
pavement, that is kept clear of fixed objects. If vehicles drive off the road,
for whatever reason, the drivers have leeway to regain control of the vehicle
and steer back onto the road. The clear zone also permits disabled vehicles to
pull off the roadway. Clear zones are established to provide an extra margin of
safety for travelers.
Minimum clear zone standards have been specified by the Florida Department of
Transportation for the design of roadways. New highways always include clear
zones when they are built. The width of the clear zone depends upon the type of
roadway, the speed of vehicles traveling on the roadway, and several other
criteria. Rural Interstate highways, with heavy traffic and high speeds, should
have a clear zone at least 30 feet wide. A city street with curbs and a 35 mph
speed limit requires a minimum 2 feet of clear zone behind each curb. Other
clear zone widths are specified for each different type of road. Clear zones
should be wider along the outside edge of curves, since out-of-control vehicles
are more likely to run off that side of the road.
Other elements considered when specifying clear zone width include the slope
of the shoulder, the depth of roadside ditches, railroad crossing equipment, and
existing structures or buildings that may be very difficult to relocate when a
road is widened. Objects that cannot be removed from the clear zone need
protective devices like crash cushions or guardrail installed to protect drivers
and passengers.
Clear zones can be enhanced with some innovative techniques. Using selected
plant species, landscaping can provide a natural crash cushion of thick
shrubbery or bushes. Placing electric and telephone lines underground will
eliminate concrete poles along the side of the road. Billboards and other large
signs can be built using supports that angle away from the roadway. Smaller
signs can use special breakaway supports. Street lights can bolt to low-profile
concrete foundations. Stormwater drains and culverts can be designed for
vehicles to drive over them rather than crash into them.
Trees, business signs, or local landmarks are sometimes identified for
relocation during a road widening project in order to provide an adequate clear
zone. It is often difficult for residents to accept the need for relocating such
objects to accommodate a larger road, but highway designers are responsible to
the public for developing the safest practical roadway design.
When you see damaged light poles, heavily scarred tree trunks, or guardrail
installed around a chipped concrete foundation and think about the events that
caused the damage, you will understand why engineers insist on adequate roadside
clear zones.
For more information:
1. Florida DOT: Minimum Standards for Design, Construction and Maintenance
for Streets and Highways, 1994; Chapter 3
2. Florida DOT: 1994 Roadway and Traffic Design Standards; Index Number 700
3. Wright and Paquette: Highway Engineering, 4th Edition, 1979; Chapter 11
4. American Association of State Highway and Transportation Officials: A
Policy on Geometric Design of Highways and Streets, 1990.
Bike Path standards are presented in a publication entitled "Bicycle
Facilities Planning and Design Manual" published by the Florida Department of
Transportation. This Manual contains the information necessary to plan, locate,
select, and design bicycle facilities.
The FDOT Manual defines Bicycle Path as "a bikeway which is physically
separated from motorized vehicle traffic by an open space or barrier and which
is either within the highway right of way or within an independent right of way.
Crossflows with motorized traffic are minimized."
A copy of the FDOT Bicycle Facilities Planning & Design Manual may be
obtained from the FDOT Maps and Publications Section, 605 Suwannee Street,
Tallahassee, Florida 32301-8064, Phone: (904) 488-9220, SUNCOM 278-9220.
A summary of the minimum FDOT Bicycle Path standards for planning
purposes are:
WIDTH (FT) 10' 8'
DESIGN SPEED (MPH) 20 MPH OR HIGHER 20 MPH
VERTICAL CLEARANCE (FT) 10' 8.2'
OVERHEAD
STOPPING SIGHT DISTANCE (FT) 130' AT 0% GRADE 130' AT 0% GRADE
FOR 20 MPH DESIGN SPEED 140' AT 5% GRADE 140' AT 5%
GRADE
MINIMUM RADIUS (FT) 95' OR MORE 95'AT 2% SUPERELEVATION
FOR 20 MPH DESIGN SPEED
SUPERELEVATION (%) 2% TO 5% 2% TO 5%
MAXIMUM GRADE (%) 2% 4% TO 5%
MINIMUM CROSS SLOPE (%) 2% TO 3% 2% TO 3%
FOR DRAINAGE
SEPARATION FROM TREES, POLES, 3' OR MORE 2'
WALLS, FENCES, GUARDRAILS (FT)
SEPARATION FROM CANALS, WIDE SEPARATION 7' OR USE POSITIVE
BARRIER
DITCHES, ETC. (FT) (Should SUCH AS DENSE SHRUBBERY
be a graded area with no OR CHAIN LINK FENCE AT
greater than a 5% slope) LEAST 4.5' HIGH.
SEPARATION FROM ROADWAY (FT) WIDE SEPARATION 5' OR USE PHYSICAL
DIVIDER SUCH AS A FENCE, DENSE SHRUBS OR OTHER.
DIVIDER SHALL BE A MINIMUM OF
4.5' HIGH.
MINIMUM HEIGHT OF BARRIERS (FT) 4.5'
DRAINAGE GRATE LOCATION KEEP OUT OF KEEP OUT OF
BICYCLISTS
BICYCLISTS EXPECTED EXPECTED PATH.
PATH.
RAILROAD CROSSINGS ANGLE PATH SHOULD CROSS AT 45
(DEGREES) RIGHT ANGLE (90)
TO THE RAIL.
PAVEMENT STRUCTURAL SECTION 4"-6" PORTLAND CEMENT 1"-2" ASPHALTIC
CONCRETE
CONCRETE SURFACE SURFACE 3-4"
STABILIZED
ON COMPACTED LIMEROCK BASE ON
COMPACTED
SUBGRADE.
SIGN CLEARANCE TO BOTTOM (FT) 7' 7'
Transportation Demand Management (TDM) focuses on ways of influencing
the amount and the time of the demand on transportation. It encourages
alternatives to the single-occupant automobile and more efficient use of the
transportation system by altering the demand characteristics. When properly
used, TDM actions can promote the use of public transportation, increase the
people moving capacity of the transportation system and allow the transportation
system to support a higher development density.
TDM TECHNIQUES are divided into the following three categories:
1. Promote alternatives to the automobile by encouraging persons to
switch to other modes of travel such as transit, bicycles, or walking. The
following techniques can be used:
a) Park-and-Ride service
b) Shuttle Systems
c) Pedestrian Systems
d) Employer Transit Subsidies
e) Bicycling
2. Encourage more efficient use of automobiles and roads by use of
Ride Sharing and Alternative Work Hours. The following techniques can be used:
a) High-Occupancy Vehicle (HOV) Lanes
b) Ride Sharing
c) Alternative Work Hours
d) Truck Traffic Restrictions
3. Discourage the use of automobiles by making their use more costly
or more difficult. The following techniques can be used:
a) Limiting on-Street Parking.
b) Limiting off-Street Public Parking
c) Allowing developers to provide fewer than the standard number of parking
spaces in exchange for promoting other TDM activities, such as ride sharing and
variable work hours.
d) Requiring Parking Permits for Residential Areas adjacent to business
districts.
e) Increasing Long-Term (commuter) Parking Rates.
The above three TDM techniques can be used together to reduce peak-hour
traffic by five (5) to fifteen (15) percent (%).
TDM is a part of the activities of Transportation System Management (TSM). In
addition to the types of actions included in TDM, TSM includes:
Traffic Signal Timing Improvement
Turn Lane Additions
Transit Scheduling Improvement
Other Improvements related to Increased Operating Efficiency of the Existing
Transportation System.
In 1989, there were 36,312 alcohol related crashes and Florida's new DUI Law
is a serious effort to reduce the number of alcohol related vehicular deaths
which totaled 1,492 in 1989.
The new law requires police to immediately suspend the license of any driver
who has a Blood-Alcohol Content (BAC) of .10% or higher or who refuses to take a
breathalyzer test or provide a urine sample upon request of the arresting
officer. In cases of crashes with injuries or fatalities, blood tests may not be
refused without loss of license for up to 18 months. Four DUI convictions
require a lifetime revocation of a Florida driver's license. The table below
summarizes the penalties for the convicted drunk driver:
License Revocation Mandatory 180 Minimum 5 yrs., Minimum 10 yrs.,
days, up to if within 5 yrs. if within 10 yrs.
1 year. of 1st conviction. of 1st conviction.
Fine Mandatory $250. Mandatory $500. Mandatory $1,000.
(See note below) up to $500. Up to $1,000. Up to $2,500.
Imprisonment Up to 6 Mos. 10 days mandatory, 30 days mandatory,
optional. if within 3 yrs. if within 5 yrs.
of 1st conviction. of prior conviction.
Up to 9 mos. Up to 1 yr. optional.
Probation Mandatory - Up
to 1 Year with
fee paid by
offender.
Community Service At least 50
hours with costs
paid by offender.
Education Required substance
abuse course with
fee paid by
offender. Further
treatment of the
defendant may be
required by the
school.
SOURCE: AAA World Magazine, January/February 1991, American Automobile
Association
On February 13, 1991, the Florida Department of Transportation passed one of
the nation's most far reaching access management regulations. The regulation is
called Administrative Rule Chapter 14-97 Access Management Classification
System and Standards. This rule institutes minimum spacing standards for
driveway connections, median openings, and traffic signals on the State Highway
System.
By July 1992, the entire State Highway System should be categorized into
seven Access Management Classifications, each with its own minimum standard for
access management. See Exhibit 1 for the classification system for arterials.
INTERIM STANDARDS
Until highways are classified, minimum spacing standards for driveway
connections, median openings, and signals will be handled by Interim Standards
found in Rule Chapter 14-97. These Interim Standards will be based primarily on
the posted speed limit of the highway. See Exhibit 2 for the Interim Standards.
THE MEASUREMENTS
With the institution of this new Administrative Rule, the Department of
Transportation will also be measuring distances between connections and corner
clearance in a new fashion. Previously, this distance was measured from the
point of tangency to the point of curvature, but now it will be measured from
the edge of the pavement to the edge of the pavement of the other connection or
nearest intersecting road (Please see Exhibit 4). Corner clearance standards and
the connections spacing standards will be the same. This means that if the
connection spacing standard is 330 feet, the corner clearance standard will also
be 330 feet except where exempted specifically within this Rule.
THE IMPORTANT EXEMPTIONS
There are exemptions to this Rule such as small single family residential and
where "reasonable access" would be denied, such as a small landlocked parcel
with no alternate access. In this case, a single driveway would be allowed.
THE TREATMENT OF MULTIPLE PROPERTIES UNDER SINGLE OWNERSHIP
Multiple neighboring properties under single ownership will be treated as if
they were one parcel. Exemptions to this are leasehold interests in existence
before February 13, 1991, and bonafide contracts for sale anytime. Minimum
corner clearance measurements may be used where there are small corner
properties that are landlocked from having reasonable access either through a
side street or their neighbor. Where such properties exist, they may be allowed
to have driveways closer to the intersections than are called for within the
standards. Under these portions of the regulations, they will usually be
required to have restrictive driveway connections such as right-in/right-out.
Exhibit 4 is the table of the minimum corner clearance distances.
This summary is not intended to be a substitute for complete knowledge of
Rule Chapter 14-97, but is intended as an overview. We highly recommend that you
get a copy of Rule Chapter 14-97, available at Florida Department of
Transportation Media Center, Maps and Publications Sale at 605 Suwannee Street,
M.S. 12, Tallahassee, Florida 32399-0450, telephone (904)488-9220. The cost of
this document is $7.00.
Since 1956, road travel has more than tripled to nearly 1.9 trillion
vehicle-miles. At the same time, road and street mileage has seen only modest
growth: from 1970 to 1985, vehicle population grew 63 percent while road mileage
increased 5 percent. In 1987, drivers experienced 2 billion vehicle-hours of
delay on urban freeways, a 60% increase from 1984. Studies of the top U.S.
cities estimate total economic losses due to congestion at approximately $42
billion per year. Two-thirds of all urban interstate traffic is experiencing
severe congestion (defined as travel under 35 mph).
Studies estimate that travel will double to 3.8 trillion vehicle-miles by
2020. If no major improvements are made, there will be about 10 billion
vehicle-hours of delay by 2005. The driving population is aging. Today, 1 in 8
drivers is older than 65. By 2020, 1 in 5 drivers (20% of the driving
population) will be over 65.
Engineers need to look for ways to increase driver mobility while increasing
safety. The National Transportation Policy recognizes these issues by including
four strategies to address future surface transportation needs: Build New
Capacity; Manage Travel Demand; Increase Operational Efficiency; and Advance New
Technologies. One strategy with the potential to effectively provide for
increased mobility and safety is advancing new technologies. Collectively, these
technologies are known as Intelligent Transportation Systems (ITS), or smart
cars and smart highways.
IVHS represents the marriage of the vehicle, the driver and the highway to
improve system efficiency and driver safety. There are four elements of ITS:
- Advanced Traffic Management System (ATMS) - Commercial Vehicle Operations
(CVO)
- Advanced Traveler Information System (ATIS) - Advanced Vehicle Control
System (AVCS)
IVHS shows promise for increased safety: by 2010, they could save an
estimated 11,500 lives and prevent 442,000 injuries annually.
Advanced Traffic Management Systems
Much like air traffic controllers at an airport, these systems are intended
to monitor, control and manage traffic. ATMS will:
- Work in real-time
- Use algorithms to predict congestion and implement countermeasures
- Use area-wide surveillance and detection to develop optimal solutions
- Coordinate control of freeways and arterials
- Provide rapid response to incidents
- Provide information to individual vehicles
- Be able to cover multiple jurisdictions
ATMS should substantially reduce congestion by reducing delays an estimated
10 to 35 percent. The greatest potential for reduced delay is through improved
incident management strategies - one minute saved in clearing an incident
reduces the duration of congestion by at least 4 to 5 minutes. ATMS also helps
reduce crashes by improving traffic conditions. (Source: Public Roads, U.S. DOT
- FHWA, December 1990)
Improve Land Use Planning
- Reduce trip generation rate per acre
- Increase number and width of corridors set aside for roads
- Require increased investment by investors
Add or Improve Mass Transit (Extremely expensive)
Build New Roads (Extremely expensive)
Increase Capacity of Existing Roads
- Widen roads (Very expensive)
- Widen intersections only (Expensive)
- Set up ONE-WAY street pairs or networks (Operational complications)
- Upgrade roads by: a. new striping
b. curb and gutter
c. reduce access points
d. reduce other side friction
- Upgrade traffic signals by: a. re-phasing signals (Comparatively
inexpensive)
b. re-timing signals (Very high benefit/cost ratio)
- Add new signals - carefully or capacity may be reduced
- Remove unwarranted signals (Inexpensive)
- Re-evaluate use of ALL-STOP, STOP, and YIELD signs
- Implement a reversible lane control system (Operational complications)
Improve Incident Management
- Repair signals and signs more expeditiously (Comparatively inexpensive)
- Set up detours if needed more expeditiously
- Advise drivers to avoid individual incidents by: a. public radio broadcasts
b. variable message signs
c. CCTV monitoring of major intersections and corridors
- Remove/tow debris more expeditiously
- Prevent incidents from being visible by: a. creating visual barriers in
freeway medians
b. curtaining off individual incidents
- Move violators away from other traffic for ticketing
Modify Drive Behavior
- Educate drivers: a. driving school
b. license test
c. public service broadcasts
d. newspaper articles
- Ticket violators
- Encourage car-pooling
- Stagger working hours
- Encourage use of mass transit
- Encourage use of alternate private transport: a. walking
b. bicycling
c. motorbiking
- Encourage living closer to work
- Encourage businesses to locate near residences
A pedestrian signal allows a safe way for pedestrians to cross the street at
signalized intersections. The pedestrian signal, when activated, provides time
for the pedestrian to enter the street on the steady "WALK" signal and finish
crossing the street on the flashing "DONT WALK" SIGNAL. The pedestrian signal is
activated by a pedestrian detector push-button, which causes the controller to
operate a pre-programmed timed sequence of steady "WALK" and flashing "DONT
WALK" indications.
Pedestrian signal indications consist of "WALK" and "DONT WALK"
signals or international symbols displaying a person walking for the "WALK"
indication and a hand for the "DONT WALK" indication. The "WALK" or person
walking symbol is displayed in white and the "DONT WALK" or hand symbol is
displayed in Portland orange.
The pedestrian signal sequence begins when the "WALK" indication is
illuminated. This sequence should be at least 4 to 7 seconds long and allow
enough time to leave the curb and begin crossing the street before the clearance
interval begins. At locations where large numbers of pedestrians are crossing, a
longer "WALK" interval may be warranted.
The pedestrian clearance interval consists of a flashing "DONT WALK"
indication. During this interval the pedestrian should complete his crossing,
however; he should not begin crossing on the flashing "DONT WALK" signal. The
clearance interval timing is based on the street width divided by 4 feet per
second walking time. If elderly pedestrians are using the crossing it is
recommended that the walk speed be reduced to 3.5 feet per second. The distance
is measured across the street: from the curb on the near side to the center of
the last lane on the far side of the street.
The "DONT WALK" indication, steadily illuminated, means that a pedestrian
should not enter the street in the direction of the pedestrian signal.
The design requirements for a pedestrian signal require that a
pedestrian signal be mounted at least 8 feet, but no higher than 10 feet, above
the sidewalk. The pedestrian signal shall be so positioned and adjusted as to
provide maximum visibility to the pedestrian. The pedestrian detector
push-button is usually found on the pole under the pedestrian signal head that
faces the crossing direction. A sign shall be mounted above the detector unit
explaining its purpose and the positioning of the push-button should clearly
indicate which crosswalk signal is activated by each push-button.
WARNING-Both pedestrians and drivers must be particularly alert
while pedestrians are crossing, especially when "Right turn on Red" movements
are allowed.
BACKGROUND
The increasing needs of older road users are becoming more apparent as a
greater proportion of our nation's motorists fall into the 65 or older age
group. The natural aging process results in a steady decrease in the abilities
needed to perform the driving task. The effect of aging upon vision, hearing,
coordination, range of movement, strength, attentiveness and response time have
been well documented through research.
Concern over how these limitations affect motorists ultimately resulted in
the preparation of the Transportation Research Board's Special Report 218,
"Transportation in an Aging Society," in 1988. This report summarizes mobility
concerns, the problems older drivers have with vehicle operation, and current
highway design deficiencies related to older driver abilities. The report
presents recommendations for corrective improvements in the following areas:
1. Roadway design and operation.
2. Traffic control devices (signs, signals and markings).
3. Vehicle safety.
4. Driver screening and licensing.
5. Vision screening.
6. Alternative means of transportation.
Implementation of these recommendations would improve the mobility and safety
of older persons, and most of the improvements would benefit all age groups.
FHWA FOLLOW-UP
The Federal Highway Administration supported the TRB's recommendations and
developed an action plan to implement the highway-related recommendations of the
report. Their "Action Plan for Older Persons," dated February 1989, presented
strategies for the following:
1. Highway safety data needs.
2. Traffic control device improvements.
3. Roadway design improvements.
4. Pedestrian improvements.
5. Older person awareness training.
RECOMMENDATIONS
The Florida Department of Transportation (FDOT) will prepare recommendations
on specific engineering enhancements to meet the requirements of the older
road-user. Concurrent with this effort, the FDOT will be identifying locations
and facility types on which to use these enhancements.
Specific design improvements to benefit the older road-user may include:
Improved signing - Increased letter size, retroreflectivity, better
placement, multiple and mid-block signing, trailblazing and use of symbols.
Improved pavement marking and delineation - Size of markings, use of
edge and centerlines on low volume roads, improved maintenance and inspection,
more pavement arrows and words.
Improvements to traffic signals - Larger signal faces, better located
within field of view, longer walk phase for pedestrian signals, improved
maintenance.
Improved sight distance - For stopping, decision making,
intersections, and clear sight line.
Improved intersection configurations - Simplify designs, provide
protected left turns, grade separations for very high volumes with confusing
movements.
Improved roadway designs - For better channelization, increase use of
medians, minimize hazards and unexpected obstacles, eliminate grade crossings.
Improved pedestrian crossings - Provide refuge islands, utilize high
visibility crossing pavement markings, re-evaluate pedestrian walk speeds.
Improved roadway lighting - Reduce headlight glare with glare screens
and open graded asphalt at pedestrian crossings, interchanges, intersections and
mainlines.
These representative design improvements have been proven to benefit the
older road-user. The FDOT also recommends that the Department of Highway Safety
and Motor Vehicles periodically test all road users on traffic control
devices since technology and regulations can and do change.
Travellers have two basic needs for roadways: (1) to travel efficiently from
origin to destination, and (2) for access to the roadway system. Accordingly,
roadways have two primary functions: (1) to carry heavy volumes of traffic at
high rates of speed, and (2) to provide access to land. The corresponding
facilities are known as arterial roads, and local roads, respectively. Since
traffic volumes on arterial roads are normally heavy, the main function of an
arterial road is to serve an efficient network supporting high-speed travel and
provide capacity to maintain adequate travel speeds.
These two functions, traffic service and land access, are incompatible. A
roadway that serves one function cannot serve the other function effectively.
Heavy volumes and high-speed traffic on local roads disrupt residential
settings, subject pedestrians and pedalcyclists to hazards, and conflict with
the safety and ease of land access. These effects counteract the purpose of
local roads. Similarly, slow traffic operations caused by points of land access
disrupt the traffic flow, reduce arterial speeds, increase crash potential, and
reduce traffic-carrying capabilities. These effects degrade traffic service,
increase congestion, and counteract the purpose of arterial roads. Also,
degradation of arterial function can cause traffic to seek short-cuts on local
streets by speeding through neighborhoods; defeating the purpose of local roads.
Since the two primary functions of roadways are incompatible, a third class
of roadway is needed to serve as an interface between the local and arterial.
These are collector roads, which collect traffic from the local roads and
intercept the arterial roads at locations spaced to minimize disruptions.
A leading consideration associated with functionally classified roadways is
to overcome the popular misconception that any roadway can serve multiple
functions. Multiple functions result in wasteful consumption of energy,
transport time, and in allowing concessions that are irreversible. Because of
these functional incompatibilities, it is essential to recognize and preserve
the functional integrity of arterial, collector and local roads, not just for
now, but also for future generations.
The term ISTEA (pronounced Ice Tea) refers to the "Intermodal Surface
Transportation Efficiency Act of 1991. This law was signed by President Bush on
December 18, 1991. This important bill provides for the renewal of our surface
transportation programs to address the changing needs for America's future. It
will create jobs, reduce congestion and rebuild our infrastructure.
ISTEA will provide $155 billion for highways, highway safety and mass
transportation for the next 6 years (FY 1992-1997). The purpose of the Act is
given in its statement of policy: "To develop a National Intermodal
Transportation System that is economically efficient, environmentally sound,
provides the foundation for the Nation to compete in the global economy and will
move people and goods in an energy efficient manner."
Some of the major features include:
* A National Highway System (NHS), consisting primarily of existing
Interstate routes. A portion of the Primary System is established to focus
Federal resources on roads that are the most important to interstate travel and
national defense, roads that connect with other modes of transportation, and are
essential for international commerce.
* State and local governments are given more flexibility in determining
transportation solutions, whether transit or highways. This will provide the
tools for enhanced planning and management systems to guide them in making the
best choices.
* New technologies, such as Intelligent Transportation System (ITS) and
prototype magnetic levitation systems (MAGLEV) are funded to push the Nation
forward into thinking of new approaches in providing 21st Century
transportation.
* The private sector is tapped as a source for funding transportation
improvements. Restrictions on the use of Federal funds for toll roads have been
relaxed and private entities may even own such facilities.
* The Act continues discretionary and formula funds for mass transit.
* Highway funds are available for activities that enhance the environment,
such as wetland banking, mitigation of damage to wildlife habitat, historic
sites, activities that contribute to meeting air quality standards, a wide range
of bicycle and pedestrian projects, and highway beautification.
* Highway safety is further enhanced by a new program to encourage the use of
safety belts and motorcycle helmets.
* State uniformity in vehicle registration and fuel tax reporting is
required. This will ease the record keeping and reporting burden on businesses
and contribute substantially to increased productivity of the truck and bus
industry.
The transportation profession has been in a state of change, especially since
the introduction of microcomputers. Transportation analysis techniques are
continuously being refined and improved as more studies and data become
available. The following manuals, handbooks and related software, used by
transportation professionals, undergo frequent updating:
- Highway Capacity Manual (HCM) and Software by the Transportation
Research Board
- Manual On Uniform Traffic Control Devices (MUTCD) by the U.S.
Department of Transportation
- Trip Generation Manual and Related Software by the Institute of
Transportation Engineers
- Parking Generation Manual by the Institute of Transportation
Engineers
- Manual Of Uniform Minimum Standards for Design, Construction and
Maintenance of Streets and Highways (Green Book) by the Florida Department
of Transportation
- A Policy On Geometric Design of Highways and Streets by the American
Association of State Highway and Transportation Officials (AASHTO)
- Level Of Service Manual by the Florida Department of Transportation
- Bikeway Facilities Planning and Design Manual by the Florida
Department of Transportation
Workshops provide transportation professionals with updates of analysis
techniques. Meetings such as those held by the Institute of Transportation
Engineers provide a forum for engineers and planners to exchange information.
The Institute of Transportation Engineers (ITE) is made up of more than 11,000
transportation engineers and planners in over 70 countries. These transportation
professionals are responsible for the safe and efficient movement of people and
goods on streets, highways and transit systems. Since 1930 the Institute has
been providing transportation professionals with programs and resources to help
them meet those responsibilities. Institute programs and resources include
professional development seminars; technical reports; a monthly journal; local,
regional and international meetings; and other forums for the exchange of
opinion, ideas, techniques, and research.
Members of the Florida Section of ITE meet three times each year to share and
discuss information on various transportation topics. Technical committees
include:
Access Management
Growth Management
Residential Traffic Control
Traffic Information Program Series (TIPS)
LEFT TURN SIGNAL PHASING
Left turn signal phases facilitate left turning traffic and usually improve
the safety of the intersection for left turning vehicles. However, this is done
at the expense of the amount of green time available for through traffic and
will usually reduce the capacity of the intersection. Left turn arrows also
result in longer cycle lengths which will in turn have a detrimental effect by
increasing stops and delays. Pedestrian delays may be increased and due to the
increased delay, pedestrians may elect to ignore the pedestrian signal.
While phases for protected left turning vehicles are the most popular and
most often added phases, other methods of handling left turn conflicts should be
considered first. Potential solutions include prohibited left turns and
geometric improvements.
LEFT TURN PHASE CRITERIA
The left turn phase criteria suggested below are a combination of left
turning phasing used in several States in the United States and the result of
considerable research and study. These warrants are not mandated by the Manual
on Uniform Traffic Control Devices (MUTCD) and are provided for information
purposes only. Suggested warrants are as follows:
Volumes - Consider left turn phasing when the product of left turning
and opposing volumes during peak hours exceed 100,000 on a four lane street, or
50,000 on a two lane street (1 approach lane). Also, the left turn volume for 2
or more approach lanes should be greater than 2 vehicles per cycle during the
peak hour period. Volumes meeting these levels indicate that a left turn phase
may be justified and further study of the intersection is recommended.
Delay - Consider installing left turn phasing if a left turn total
delay of 2 vehicle hours or more occur in a peak hour on a critical approach.
Also, there should be a minimum left turn volume of greater than 2 vehicles per
cycle during peak hour, and the average delay for left turning vehicle should be
at least 35 seconds.
Crash Experience - Install left turn phasing if the critical number of
left turn crashes has occurred. For one approach, the critical number is 4 left
turn crashes in one year, or 6 in two years. For both approaches, the critical
number is 6 left turn crashes in one year, or 10 in 2 years.
PROTECTED/PERMITTED LEFT TURN PHASING
Protected/permitted left turn phasing is a left turn movement of traffic at a
signalized intersection having a separate left turn phase in the signal cycle to
provide a protected green arrow interval, as well as nonprotected circular green
interval. Use of the protected/permitted left turn phasing technique is based on
the assumption that the need for a protected left turn interval has been
established. One of the basic precepts of the protected/permitted left turn
phasing, is that the protected green arrow is displayed only when needed in a
traffic demand condition. It is therefore emphasized that the
protected/permitted left turn phasing technique is an efficient concept as
opposed to a crash reduction concept although it will probably offer safer
operation than permissive only operation.
PROTECTED ONLY LEFT TURN PHASING
When a separate interval is provided to accommodate a left turn without
conflicting traffic, and left turns are prohibited during the rest of the cycle,
protected only left turn phasing occurs.
Although the MUTCD provides no left turn phasing warrants, the traffic
control device handbook offers suggested guidelines for separate left turn
phasing.
UNPROTECTED LEFT TURN PHASING
Unprotected left turn phasing occurs when an exclusive phase is not provided
for left turn vehicles. Left turns are permitted to occur through gaps in the
opposing traffic flow. Separate left turn lanes may or may not be provided.
Metrication is the process of conversion to the metric system. This
process has begun in the U.S. and will be totally established by 1996. The
conversion applies to all FHWA manuals, documents, publications, reporting and
construction contracts. All programs authorized under titles 23 and 49,
U.S.Code, and related highway acts shall be converted to metric. The conversion
will be mandatory, not voluntary as in the past, for all procurements, grants
and other business-related activities, except to the extent that such conversion
is impractical or is likely to cause significant inefficiencies or loss of
markets to U.S. firms.
Acres (Area) 0.4047 Hectares
Acres (Area) 4047.0000 Square Meters
Centigrade (Temperature) (oCx9/5)+32 Fahrenheit
Centimeters (Length) 10.0000 Millimeters
Centimeters (Length) 0.3937 Inches
Cubic Feet (Volume) 0.02832 Cubic Meters
Cubic Meters (Volume) 35.314 Cubic Feet
Cubic Yards (Volume) 0.7646 Cubic Meters
Cubic Meters (Volume) 1.3079 Cubic Yards
Fahrenheit (Temperature) (oF-32)x1.8 Centigrade
Feet (Length) 0.3048 Meters
Feet (Length) 30.4800 Centimeters
Gallons (U.S.) (Volume) 3.785 Liters
Grams (Weight) 0.03527 Ounces
Grams (Weight) 453.5900 Pounds
Hectares (Area) 2.571 Acres
Inches (Length) 25.40 Millimeters
Inches (Length) 2.540 Centimeters
Inches (Length) 0.2540 Meters
Kilograms (Weight) 2.2046 Pounds
Kilograms (Weight) 35.2736 Ounces
Kilometers (Length) 0.6214 Miles
Kilometers Per Hour (Speed) 0.6214 Miles Per Hour
Kilometers Per Hour (Speed) 0.9113 Feet Per Second
Liters (Volume) 1.0567 Quarts
Liters (Volume) 0.2642 Gallons (U.S)
Meters (Length) 100.0000 Centimeters
Meters (Length) 1000.0000 Millimeters
Meters (Length) 3.2808 Feet
Meters (Length) 1.0936 Yards
Metric Tons (Weight) 0.98421 English Tons
Miles (Length) 1.6094 Kilometers
Miles Per Hour (Speed) 1.6093 Kilometers Per Hour
Milligrams (Weight) 0.0010 Grams
Millimeters (Length) 0.1000 Centimeters
Millimeters (Length) 0.0010 Meters
Ounces (Weight) 28.35 Grams
Pounds (Weight) 0.4536 Kilograms
Square Meters (Area) 10.764 Square Feet
Square Miles (Area) 2.590 Square Kilometers
Yards (Length) 91.44 Centimeters
Yards (Length) 0.9144 Meters
ADIS ADVANCED DRIVER INFORMATION SYSTEMS, RENAMED AS ADVANCED TRAVELER
INFORMATION SYSTEMS.
AHAR AUTOMATIC HIGHWAY ADVISORY RADIO.
AI ARTIFICIAL INTELLIGENCE.
AMTICS ADVANCED MOBILE TRAFFIC INFORMATION AND COMMUNICATION SYSTEM.
API AUTOMATIC PERSONAL IDENTIFICATION.
APTS ADVANCED PUBLIC TRANSPORTATION SYSTEMS.
ATIS ADVANCED TRAVELER INFORMATION SYSTEMS.
ATMS ADVANCED TRAFFIC MANAGEMENT SYSTEMS.
ATSAC AUTOMATED TRAFFIC SURVEILLANCE AND CONTROL SYSTEM (LOS ANGELES).
AVC AUTOMATIC VEHICLE CLASSIFICATION.
AVCS ADVANCED VEHICLE CONTROL SYSTEMS.
AVI AUTOMATIC VEHICLE IDENTIFICATION.
AVL AUTOMATIC VEHICLE LOCATION.
AVM AUTOMATIC VEHICLE MONITORING.
CARIN CAR INFORMATION AND NAVIGATION SYSTEM.
CB CITIZEN BAND.
CCTV CLOSED CIRCUIT TELEVISION.
CMS CHANGEABLE MESSAGE SIGNS (ALSO VARIABLE MESSAGE SIGNS, VMS).
COM-TV COMMUTER-TV SYSTEM.
CVI COMMERCIAL VEHICLE IDENTIFICATION.
CVO COMMERCIAL VEHICLE OPERATIONS.
EMS EMERGENCY MANAGEMENT SYSTEM.
ETTM ELECTRONIC TOLL AND TRAFFIC MANAGEMENT.
FLAMINGO FLORIDA MOTORISTS INFORMATION NETWORK FOR GUIDANCE AND OPERATIONS
(MIAMI).
FSS FIXED SATELLITE SERVICE.
HAR HIGHWAY ADVISORY RADIO.
HELP HEAVY VEHICLE ELECTRONIC LICENSE PLATE PROGRAM.
HOV(S) HIGH OCCUPANCY VEHICLE(S).
HUD HEAD-UP DISPLAY.
HVCO HEAVY VEHICLE & COMMERCIAL OPERATIONS.
ICS INTELLIGENT CORRIDOR SYSTEM.
ILD INDUCTIVE LOOP DETECTORS.
IMS INCIDENT MANAGEMENT SYSTEM.
INFORM INFORMATION FOR MOTORISTS.
IRTE INTEGRATED ROAD TRANSPORT ENVIRONMENT.
ITS INTELLIGENT TRANSPORTATION SYSTEMS.
IVSAWS IN-VEHICLE SAFETY ADVISORY AND WARNING SYSTEMS.
LCD LIQUID CRYSTAL DISPLAY.
LED LIGHT EMITTING DIODE.
OBC ON-BOARD COMPUTERS.
PATH PROGRAM ON ADVANCED TECHNOLOGY FOR THE HIGHWAY (CALIFORNIA).
PGI PARKING GUIDANCE AND INFORMATION.
PIN PERSONAL IDENTIFICATION NUMBER.
PROMETHEUS PROGRAM FOR EUROPEAN TRAFFIC WITH HIGHEST EFFICIENCY AND
UNPRECEDENTED SAFETY.
RACS ROAD AUTOMOBILE COMMUNICATION SYSTEM (JAPAN).
RDS RADIO DETERMINATION SATELLITE SERVICES.
RTI ROAD TRANSPORT INFORMATICS (EUROPEAN TERM FOR IVHS).
TARDIS TRAFFIC AND ROADS - DRIVE INTEGRATED SYSTEM.
TMC TRAFFIC MANAGEMENT CENTER.
VMS VARIABLE MESSAGE SIGNS (ALSO CHANGEABLE MESSAGE SIGNS).
AAA AMERICAN AUTOMOBILE ASSOCIATION
AASHTO AMERICAN ASSOCIATION OF STATE HIGHWAY & TRANSPORTATION OFFICIALS
APA AMERICAN PLANNING ASSOCIATION
APTA AMERICAN PUBLIC TRANSIT ASSOCIATION
APWA AMERICAN PUBLIC WORKS ASSOCIATION
ASCE AMERICAN SOCIETY OF CIVIL ENGINEERS
CAC CITIZENS ADVISORY COMMITTEE
CALTRANS CALIFORNIA DEPARTMENT OF TRANSPORTATION
CEC COMMISSION OF THE EUROPEAN COMMUNITY
CUTR CENTER FOR URBAN TRANSPORTATION RESEARCH (UNIVERSITY OF S. FLORIDA)
DCA DEPARTMENT OF COMMUNITY AFFAIRS (FLORIDA)
DHS&MV DEPARTMENT OF HIGHWAY SAFETY & MOTOR VEHICLES (FLORIDA)
DOT DEPARTMENT OF TRANSPORTATION (U.S. OR FLORIDA)
ECFRPC EAST CENTRAL FLORIDA REGIONAL PLANNING COUNCIL
FAA FEDERAL AVIATION ADMINISTRATION (U.S. D.O.T.)
FAPA FLORIDA CHAPTER - AMERICAN PLANNING ASSOCIATION
FBT FLORIDIANS FOR BETTER TRANSPORTAITON
FDOT FLORIDA DEPARTMENT OF TRANSPORTATION
FES FLORIDA ENGINEERING SOCIETY
FHP FLORIDA HIGHWAY PATROL (DHS&MV)
FHWA FEDERAL HIGHWAY ADMINISTRATION (U.S. D.O.T.)
FPZA FLORIDA PLANNING & ZONING ASSOCIATION
FRA FEDERAL RAILROAD ADMINISTRATION (U.S. D.O.T.)
FSITE FLORIDA SECTION - INSTITUTE OF TRANSPORTATION ENGINEERS
FSU FLORIDA STATE UNIVERSITY
FTA FEDERAL TRANSIT ADMINISTRATION (FORMALLY UMTA) U.S. D.O.T.
IIHS INSURANCE INSTITUTE FOR HIGHWAY SAFETY
ITE INSTITUTE OF TRANSPORTATION ENGINEERS
McTRANS MICROCOMPUTERS IN TRANSPORTATION (UNIVERSITY OF FLORIDA)
MPO METROPOLITAN PLANNING ORGANIZATION (LOCAL)
NHTSA NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION (U.S. D.O.T.)
NRC NATIONAL RESEARCH COUNCIL
NSC NATIONAL SAFETY COUNCIL
SWFRPC SOUTHWEST FLORIDA REGIONAL PLANNING COUNCIL
TAC TECHNICAL ADVISORY COMMITTEE
T2 TECHNOLOGY TRANSFER (EACH STATE)
TRB TRANSPORTATION RESEARCH BOARD (NATIONALA RESEARCH COUNCIL)
TRC TRANSPORTATION RESEARCH CENTER (U. OF F.)
TTI TEXAS TRANSPORTATION INSTITUTE
UCF UNIVERSITY OF CENTRAL FLORIDA
UF UNIVERSITY OF FLORIDA
UMTA URBAN MASS TRANSIT ASSOCIATION (CHANGED TO FTA)
U.S. D.O.T. UNITED STATES DEPARTMENT OF TRANSPORTATION
USF UNIVERSITY OF SOUTH FLORIDA
UTEC URBAN TRAFFIC ENGINEERS COUNCIL (ITE)
Traffic Engineers are reluctant to install "Deaf Child" or "Blind Child"
Warning Signs for individuals for the following reasons:
- A "Deaf Child" or "Blind Child" Sign does not describe to the motorists
where the child might be. Most streets within a residential area have children
who react in the same way, and each driver must be aware of all children in a
neighborhood environment.
- Special signs such as "Deaf Child" or "Blind Child" signs provide parents
and children with a false sense of security that their children are safe when
playing on or near the street, when playing in the street is actually an unsafe
practice.
Many attempts to attract the driver's attention through the use of unique and
unusual signs have been made. Some examples include messages warning of children
at play, of domestic animals crossing, of special speed limit enforcement, and
odd-value advisory safe speed signs. Usually, these unique signs are installed
as a result of emotional and political pressure.
Unfortunately, the novelty effect wears off quickly and the signs no longer
attract the attention of regular passers-by. They are a target for vandals and
souvenir hunters and have a high replacement cost. Unique message signs have no
legal meaning or established precedent for use in basic traffic engineering
references; their use is discouraged because of both the lack of proven
effectiveness and undesirable liability exposure.
Many Traffic Engineers feel that special warning signs are warranted at a
location adjacent to a school for the deaf or for the blind and have
considerably more merit than those at a location where a deaf or blind person
may only cross occasionally.
Florida Law treats bicycle riders of all ages the same as motor
vehicle drivers, except for licensing requirements and laws which by their
nature can have no application to bicycles. The law imposes additional
requirements on bicyclists, most of which are contained in Section 316.2065,
Florida Statutes. The major requirements are summarized below.
When operated on a street, a bicycle is subject to the same rules which apply
to all vehicles. A bicyclist must travel in the same direction as other traffic
and obey all traffic control signs and signals (stop signs, traffic lights,
etc.). Bicyclists also are required to use hand signals when turning or
stopping. Except when turning left or passing, bicycles must be kept as close as
practicable to the right side of the road (or left if on a one-way street).
Unless signs are posted prohibiting access, Florida law permits bicycles to
be ridden on all streets and highways other than interstates, Florida's
Turnpike, and similar limited-access roads. Bicycles also are permitted on
sidewalks except where prohibited by local ordinance.
Bicycles may not be ridden more than two abreast. When ridden two abreast,
bicycles may not impede the normal flow of traffic and must occupy only a single
lane.
When on a sidewalk or crosswalk, a bicyclist has the same rights and
responsibilities as a pedestrian. However, a bicyclist must yield the
right-of-way to a pedestrian and must give an audible signal before overtaking
and passing a pedestrian.
When operated between dusk and dawn, a bicycle must be equipped with a
headlamp exhibiting a white light visible from at least 500 feet and both a lamp
and a reflector on the rear, each exhibiting a red light visible from at least
600 feet. Additional lights and reflectors, both on the bicycle and on the
rider, are permitted and encouraged when riding at night in order to increase
the visibility of the bicycle for drivers of other vehicles.
All bicycles must be equipped with brakes. The brakes must be capable of
stopping a bicycle going 10 miles per hour within 25 feet on dry, level, clear
pavement.
The driver of a bicycle must be on a permanent seat and keep at least one
hand on the handlebars at all times. Bicyclist may not attach themselves or
their bicycles to other vehicles.
The number of people allowed to ride on a bicycle is limited to the number
for which the bicycle is designed or equipped. Passengers may not be carried on
the handlebars or frame of the bicycle. However, an adult may carry a child in a
sling or a backpack while riding a bicycle (this is not recommended for very
young infants). Trailers may be attached to bicycles for carrying cargo.
For children under 15 years old, the fine for a violation of a traffic law
when operating a bicycle is $17. Bicyclists 15 and older receive the same fines
as motor vehicle drivers, but are not assessed points against their driver
licenses. Parents or legal guardians may be cited for a non-moving traffic
violation for knowingly allowing their minor children to operate a bicycle in
violation of the special bicycle regulations contained in Section 316.2065,
Florida Statutes.
Source:Traffic Crash Facts
Special Report: Bicycle Crashes In Florida by the Florida Department of
Highway Safety and Motor Vehicles, June 1993
DEFINITION
Partnering is a structured process through which companies identify the
barriers which prevent them from working together most effectively and then
develop specific action plans to address those barriers. It is designed to
reduce conflict, eliminate claims, improve communication and provide timely
resolution of problems.
BACKGROUND
The partnering concept began in the late 1980s with the Army Corps of
Engineers in Washington State. Adversarial relationships and increased
litigation were key factors which revealed the need for a change in contractor
owner relationships. The partnering process was developed to improve this
deteriorating relationship. Partnering usually begins with a one or two day
workshop for a particular project.
CONCEPT
The basic intent is to bring key managers of the project together to open
channels of communication, set common goals and foster a climate in which issues
can be openly raised, discussed and jointly settled at the lowest practical
level of responsibility. Team members or stakeholders are encouraged to candidly
discuss their respective interests in the project and to explore areas of
potential conflict and possible ways to resolve them. Workshops are held to
create a cooperative team spirit, trust between team members, and a step-by-step
joint issue identification and resolution process to minimize the number and
extent of disputes.
Partnering is a way of doing business with both the contracting agency and
the contractor recognizing that they have common goals which can be achieved
through cooperation and open communication. Partnering benefits the construction
industry in four areas: quality, cost, time and profit. Past partnering efforts
in both the public and private sectors have produced significant accomplishments
including cost underruns, crash reduction, reduction of rework, reduction of
construction errors, and a high level of personal satisfaction which the
contracting parties receive from working together.
The partnering concept places an emphasis on cooperation rather than
confrontation. The foundation of partnering is teamwork. Both the owner and the
contractor's organizations share a common vision and responsibility to build the
highest quality product on schedule, safely and within budget.
TEAM COMPOSITION
The composition of the team should include people from each company/entity
involved with the project. This should include: (1) the contractor and his major
sub-contractors and suppliers, (2) the owner or contracting agency's management,
project level inspectors, designers, maintenance, etc., (3) utility company
representatives: management and field level, (4) city or county engineers, and
(5) any other group or person who has a stake in the outcome of the project.
PARTNERING IN FLORIDA'S DEPARTMENT OF TRANSPORTATION
The Florida Department of Transportation adopted the partnering process in
March, 1992. Since then, more than 60 workshops have been held on construction
projects. It is at these workshops that the planning, communicating and
coordinating begin to happen. This is where project level relationships are
established and key concerns and issues first get addressed. At these workshops,
names and faces come together. Ideas, and the people proposing them, become real
and tangible. The spirit of teamwork and trust begins to develop.
Source: Greg Xanders, P.E., Partnering Coordinator, Florida Department of
Transportation, Tallahassee, Florida
The "Manual of Uniform Minimum Standards for Design, Construction and
Maintenance for Streets and Highways" (the Greenbook) by the Florida Department
of Transportation (FDOT) provides minimum standards for vertical clearances over
roadways. The FDOT manual states:
Vertical clearances should be adequate for the type of expected traffic.
Freeways and major arterials shall have a vertical clearance of at least 16
feet. Other streets and highways should have a clearance of 16 feet unless the
provision of a reduced clearance is fully justified by a specific analysis of
the situation. Provision for additional clearance (3 to 6 inches) is recommended
to allow for future resurfacing.
Passenger Car 4.25 feet
Single Unit Truck 13.5 feet
Single Unit Bus 13.5 feet
Articulated Bus 10.5 feet
Semi-Trailer 13.5 feet
The Low Clearance sign is used to warn vehicle operators of clearance less
than the maximum vehicle height permitted plus 12 inches. If a sign is placed on
the structure, it may be a rectangular shape with the legend (12) ft (6) in.
The actual clearance is normally shown on the sign to the nearest inch not
exceeding the actual clearance. However, in areas that experience changes in
temperature causing frost action, an allowance, not exceeding 3 inches, for this
condition, is recommended.
Where the clearance is less than the legal limit, a sign to that effect
should be placed at the nearest intersecting road or wide point in the road at
which a vehicle can detour or turn around.
In the case of an arch or other structure under which the clearance varies
greatly, two or more signs should be used as necessary on the structure itself,
to give information as to the clearance over the entire roadway.
Clearances should be checked periodically, particularly in areas where
resurfacing operations have taken place.
The FDOT Roadway and Traffic Design Standards for Design, Construction,
Maintenance and Utility Operations (the Standard Index) No. 17727, 2 of 2,
provides standards for traffic signal head clearance. The document states signal
heads must have a "vertical clearance of not less than 17 feet and not more than
19 feet, measured under the most critical signal assembly (with regard to
clearance) for that span."
The Florida Traffic Laws as presented in the Florida Statutes, Chapter
316.130, indicate pedestrians must follow traffic control devices and traffic
regulations as follows:
1. A pedestrian shall obey the instructions of any official traffic control
device specifically applicable to him unless otherwise directed by a police
officer.
2. Pedestrians shall be subject to traffic control signals at intersections
as provided in S. 316.075, but at all other places pedestrians shall be accorded
the privileges and be subject to the restrictions stated in this chapter.
3. Where sidewalks are provided, no pedestrian shall, unless required by
other circumstances, walk along and upon the portion of a roadway paved for
vehicular traffic.
4. Where sidewalks are not provided, any pedestrian walking along and upon a
highway shall, when practicable, walk only on the shoulder on the left side of
the roadway in relation to the pedestrian's direction of travel, facing traffic
which may approach from the opposite direction.
5. No person shall stand in the portion of a roadway paved for vehicular
traffic for the purpose of soliciting a ride, employment, or business from the
occupant of any vehicle.
6. No person shall stand on or in proximity to a street or highway for the
purpose of soliciting the watching or guarding of any vehicle while parked or
about to be parked on a street or highway.
7. When traffic control signals are not in place or in operation, the driver
of a vehicle shall yield the right of way, slowing down or stopping if need be
to so yield, to a pedestrian crossing the roadway within a crosswalk when the
pedestrian is upon the half of the roadway upon which the vehicle is traveling
or when the pedestrian is approaching so closely from the opposite half of the
roadway as to be in danger. Any pedestrian crossing a roadway at a point where a
pedestrian tunnel or overhead pedestrian crossing has been provided shall yield
the right of way to all vehicles upon the roadway.
8. No pedestrian shall suddenly leave a curb or other place of safety and
walk or run into the path of a vehicle which is so close that it is impossible
for the driver to yield.
9. Whenever any vehicle is stopped at a marked crosswalk or at any unmarked
crosswalk at an intersection to permit a pedestrian to cross the roadway, the
driver of any other vehicle approaching from the rear shall not overtake and
pass such stopped vehicle.
10. Every pedestrian crossing a roadway at any point other than within a
marked crosswalk or within an unmarked crosswalk at an intersection, shall yield
the right of way to all vehicles upon the roadway.
11. Between adjacent intersections at which traffic control signals are in
operation, pedestrians shall not cross at any place except in a marked
crosswalk.
12. No pedestrian shall, except in a marked crosswalk, cross a roadway at any
other place than by a route at right angles to the curb, or by the shortest
route to the opposite curb.
13. Pedestrians shall move, whenever practicable, upon the right half of
crosswalks.
14. No pedestrian shall cross a roadway intersection diagonally; unless
authorized by official traffic control devices, and when authorized to cross
diagonally, pedestrians shall cross only in accordance with the official traffic
control devices pertaining to such crossing movements.
15. Notwithstanding other provisions of this chapter, every driver of a
vehicle shall exercise due care to avoid colliding with any pedestrian or any
person propelling a human-powered vehicle and give warning when necessary and
exercise proper precaution upon observing any child or any obviously confused or
incapacitated person.
16. No pedestrian shall enter or remain upon any bridge or approach thereto
beyond the bridge signal, gate, or barrier after a bridge operation signal
indication has been given. No pedestrian shall pass through, around, over, or
under any crossing gate or barrier at a railroad grade crossing or bridge while
such gate or barrier is closed or is being opened or closed.
17. No pedestrian may jump or dive from a publicly owned bridge. Nothing in
this provision requires the state or any political subdivision of the state to
post signs notifying the public of this provision. The failure to post a sign
may not be construed by any court to create liability on the part of the state
or any of its political subdivisions for injuries sustained as a result of
jumping or diving from a bridge in violation of this subsection.
18. No pedestrian shall walk upon a limited access facility or a ramp
connecting a limited access facility to any other street or highway; however,
this subsection does not apply to maintenance personnel of any governmental
subdivision.
Background:
The Strategic Highway Research Program (SHRP) is a $150,000,000
product-driven research program financed under the Federal-aid highway program.
SHRP was developed in a partnership with the States, American Association of
State Highway and Transportation Officials (AASHTO), Transportation Research
Board (TRB), industry, and the Federal Highway Administration (FHWA). SHRP
includes research in asphalt, concrete and structures, highway operations, and
long-term pavement performance.
Congress, fully recognizing that this important program would require
resources to implement the findings, authorized $108,000,000 over 6 years for
both implementation efforts and for continuation of the Long-Term Pavement
Performance Program (LTPP).
Purpose:
The purpose of FHWA's SHRP Products Implementation Program is to encourage
and facilitate the application of those research findings that will improve the
quality, efficiency, safety, performance, and productivity of our Nation's
highway system.
Goals:
To fully, professionally, and aggressively communicate the SHRP products to
the U.S. highway community.
To develop and implement both short- and long-range marketing strategies for
SHRP products by taking full advantage of a variety of existing and innovative
technology transfer delivery systems.
To bring into practice those SHRP products and techniques that are
essentially complete and are implementable with minimal training and/or
evaluation.
To promote customer evaluation of those SHRP products that require use of
local materials and adaptation to regional, State, or specific industry
practices.
To advance those promising but only partially completed SHRP
products/processes through further research, development, test and evaluation,
standard setting, and institutional awareness.
To provide technical and financial assistance to public and private agencies
for the purpose of evaluating and ultimately adopting SHRP research products.
To provide training on the use of SHRP products and initiate activities that
will enhance long-range educational efforts.
To promote activities by standard setting organizations such as AASHTO,
American Concrete Institute, American Society for Testing and Materials, etc.
that enhance the acceptability and credibility of the SHRP products.
Successful Implementation Operating Principles:
Established public and private sector partnerships.
Effective communication among all partners.
Top executive awareness, understanding, and support of the program - State,
Federal, and industry-continued promotion of a highway program that is
progressive and technology centered.
Full and continuous congressional financial support.
Effective use of Federal-aid highway funds by the States to test and evaluate
SHRP products.
Continues State and industry participation on technical working and expert
task groups.
Proper identification of the scope and integration of post-SHRP findings from
national R&D programs sponsored by FHWA, National Cooperative Highway
Research Program (NCHRP), U.S. Army Corps of Engineers, Federal Aviation
Administration, private sector, etc.
Commitment of private sector to development, marketing, and support of
hardware.
Source: "Implementation Plan-Strategic Highway Research Program Products",
June 1993, U.S. Department of Transportation, Federal Highway Administration.
Background:
The general purpose of roadway lighting is to provide improved visibility for
the various users of roadways and associated facilities. The "users" may include
vehicle operators (automobiles, trucks, buses, motorcycles, bicycles),
pedestrians and other citizens such as merchants and shoppers.
Purpose:
Lighting increases the comfort and safety of the motorist. It has been noted
that lighting can be expected to reduce night crashes by about 30 percent.
The objectives of roadway lighting are:
To supplement vehicle headlights, extending the visibility range beyond their
limits both laterally and longitudinally.
To improve the visibility of roadway features and objects on or near the
roadway.
To delineate the roadway ahead.
To provide visibility of the environment.
To reduce the apprehension of those using the roadway.
LIGHT SOURCES:
There are two general types of light sources -- filament lamps and
arc-discharge lamps. The main filament lamp is the incandescent lamp. Discharge
lamps include fluorescent and high intensity discharge (HID) lamps.
1. Incandescent Lamp
* Filament wire encased in a bulb filled with an inert gas, usually hydrogen
or krypton
* Light produced by current passing through filament heating filament to
incandescence
2. Fluorescent
* Light produced by fluorescent coating on the inside of the tube. Coating
activated by ultraviolet energy which is generated by the arc.
3. Mercury Vapor
* Arc tube inside the outer bulb contains gaseous material and electrodes.
* Light produced from mercury vapor
* Lamps may be clear or coated with phosphors to improve color rendition.
4. Metal Halide
* Light produced by combination of metallic vapors
* Excellent color rendition - Sports & TV broadcast; Short lamp life
(16,000 - 18,000 hours life)
5. High Pressure Sodium (Efficient lighting/power)
* Light produced from sodium vapor
* Arc tube filled with sodium mercury and xenon. Xenon used for starting and
mercury for color.
* No starting electrode - high voltage pulse used to start arc -- 2500 to
4000 volts (24,000 hours life).
6. Low Pressure Sodium (Causes everything to look like a dirty shade
of brown)
* Very efficient
* Monochromatic -- single color only
* Large physical size - light hard to control; Lower lamp life (18,000 hours
life)
Source: "Basic Lighting Design", Participants Notebook, Developed by the
Office of Design, Florida Department of Transportation.
"High-speed magnetically levitated ground transportation (maglev) is
a new surface mode of transportation in which vehicles glide above their
guideways, suspended, guided, and propelled by magnetic forces. Capable of
traveling at speeds of 250 to 300 miles-per-hour or higher, maglev would offer
an attractive and convenient alternative for travelers between large urban areas
for trips of up to 600 miles. It would also help relieve current and projected
air and highway congestion by substituting, for short-haul air trips, thus
releasing capacity for more efficient long-haul service at crowded airports, and
by diverting a portion of highway trips." The guideway is the physical structure
along which MAGLEV vehicles are levitated. Guideway configurations proposed are:
T-shaped, U-shaped, Y-shaped, and box-beam. The guideway can be constructed of
steel, concrete or aluminum.
The three primary functions basic to MAGLEV technology are:
1. Levitation
2. Propulsion
3. Guidance
In most common designs, magnetic forces are used to perform all three
functions, although a nonmagnetic source propulsion could be used.
Levitation Systems
The two principal means of levitation are:
1. Electro Magnetic Suspension (EMS) is an attractive force levitation system
whereby electromagnets on the vehicle interact with ferromagnetic rails on the
guideway.
2. Electro Dynamic Suspension (EDS) employs magnets on the moving vehicle to
induce currents in the guideway. Resulting repulsive force produces stable
vehicle support and guidance because the magnetic repulsion increases as the
vehicle/guideway gap decreases. However, the vehicle must be equipped with
wheels or other forms of support for "takeoff" and "landing" because the EDS
will not levitate at speeds below 25 PMH.
Propulsion Systems
The three types of propulsion systems that have been proposed are:
1. "Long-stator" propulsion using an electrically powered linear motor
winding in the guideway appears to be the favored option for high-speed MAGLEV
systems. It is also the most expensive because of higher guideway construction
costs.
2. "Short-stator" propulsion uses a Linear Induction Motor (LIM) winding on
board and a passive guideway. While short-stator propulsion reduces guideway
costs, the LIM is heavy and reduces vehicle payload capacity, resulting in
higher operating costs and lower revenue potential compared to the long-stator
propulsion.
3. A nonmagnetic energy source (gas, turbine or turboprop) can be used for
propulsion, but this results in a heavy vehicle and reduces operating
efficiency.
Guidance Systems
Guidance or steering refers to the sideward forces that are required to make
the vehicle follow the guideway. The necessary forces are supplied in a uniform
fashion to the suspension forces, either attractive or repulsive. The same
magnets on board the vehicle which supply lift, can be used concurrently for
guidance; or separate guidance magnets can be used.
Source: "Final Report on the National MAGLEV Initiative" by the U.S.
Department of Transportation, September 1993.
The subject of proper placement and use, by both pedestrians and motorists,
of marked crosswalks is one which arises from time to time in discussions among
traffic engineering professionals and the lay public. This information sheet
will present facts regarding the use of Marked Crosswalks as set forth in the
State of Florida Uniform Traffic Control Regulations (Chapter 316, F.S.) and as
promulgated by the Institute of Transportation Engineers (ITE).
What are the official guidelines?
The State of Florida has set forth traffic control regulations in Chapter 316
of the Florida Statutes and, except where specifically permitted within the
statutes, all local governments must follow this code. The basic reference in
the code is the Manual On Uniform Traffic Control Devices (MUTCD) of the Federal
Highway Administration. The MUTCD has been endorsed by the ITE and is used as
the basis for much of the case law that has been made in the United States over
the past several decades.
Traffic control devices include traffic signals, traffic signs, and painted
roadway lines and markings. The MUTCD covers all aspects of the placement,
construction and maintenance of every form of approved traffic control device.
There are five basic requirements for all traffic control devices. They must:
1. Fulfill a need.
2. Command attention.
3. Convey a clear, simple meaning.
4. Command respect of road users.
5. Give adequate time for proper response.
The MUTCD emphasizes "uniformity" of traffic control devices. A uniform
traffic control device conforms to the regulations for dimensions, color,
wording and graphics. The standard device should convey the same meaning at all
times. Consistent use of traffic control devices protects the clarity of their
messages. The MUTCD also requires that similar situations be treated in the same
way.
What is a crosswalk?
Crosswalks may be either "marked" or "unmarked". Chapter 316 defines a
"crosswalk" as follows:
"(a) That part of a roadway at an intersection included within connections of
the lateral lines of the sidewalks on opposite sides of the highway, measured
from the curbs or, in the absence of curbs, from the edges of the traversable
roadway."
"(b) Any portion of a roadway at an intersection or elsewhere distinctly
indicated for pedestrian crossing by lines or other markings on the surface."
Definition (b) above refers to "marked" crosswalks. All other crosswalks are,
therefore, "unmarked". Crosswalks must be painted white and must be installed in
accordance with Florida Department of Transportation Roadway and Traffic Design
Standards.
How are crosswalks used?
Normally, pedestrians must yield the right-of way to motorists. Florida
Statutes require that pedestrians not leave a curb or other safe place such that
it is impossible for a motorist to yield. In addition, pedestrians are required
to yield to motorists whenever crossing a roadway at any point other than a
crosswalk (marked or unmarked). These requirements place the burden of crossing
at the appropriate place, and crossing in concert with the traffic signals, upon
the pedestrian. Crosswalks are marked mainly to encourage pedestrians to use a
particular crossing. Studies conducted on the relative safety of crosswalks
support minimal installation of marked crosswalks. Studies conducted in several
California locations gave surprising results. Although 2 times as many people
used the marked crosswalks, 6 to 8 times as many crashes occurred in the marked
crosswalks.
What causes crashes at marked crosswalks?
Research suggests that marked crosswalks give pedestrians a false sense of
security. Pedestrians often step off the curb expecting drivers of vehicles
approaching the crosswalk to stop. However, drivers frequently fail to stop and
cause a vehicle/pedestrian crash. At all crosswalks, both marked and unmarked,
it is the pedestrian's responsibility to be cautious and alert before
starting to cross the street.
At crosswalks on multi-lane roadways, another frequent factor in causing
crashes involves the driver of a vehicle in the lane nearest the curb stopping
for a pedestrian who is waiting to cross or who is already in the crosswalk. The
driver of a second vehicle traveling in the lane next to the stopped vehicle
tries to pass the stopped vehicle and hits the pedestrian, even though it is
illegal for drivers to pass a stopped vehicle at a crosswalk (Chapter
316.130(9)). Pedestrians should be very cautious when walking in a crosswalk,
especially when their visibility is limited by vehicles already stopped at the
crosswalk.
Where are crosswalks normally marked?
Crosswalks are marked at intersections where there is substantial conflict
between vehicle and pedestrian movements, where significant pedestrian
concentrations occur, where pedestrians could not otherwise recognize the proper
place to cross, and where traffic movements are controlled. For example:
approved school crossings
signalized and stop sign controlled intersections where there is significant
pedestrian traffic or where one or more crossing locations are prohibited
The foregoing examples follow the philosophy of using marked crosswalks to
encourage proper pedestrian crossing behavior. In the first case, school
children are encouraged to use a crossing which is normally being monitored. In
the second case, pedestrians are encouraged to avoid a prohibited crossing
movement.
In general, it is not good policy to paint crosswalk markings at midblock
locations where traffic is not controlled by stop signs or traffic signals.
Marked crosswalks should only be used where necessary to direct pedestrians
along the safest route.
What are special school crosswalks?
Crosswalks should be marked at all intersections on any "suggested route to
school", usually available through your local school district. They should also
be marked where there is high conflict between vehicles and crossing students,
where students are permitted to cross between intersections, or where students
could not otherwise cross.
7
The best safety measure for school age children is to educate them on how and
where to safely cross the street.
(Adapted from Marked Crosswalks, City of Buenaventura, CA, traffic
information brochure series 1994.)
A Traffic-Control Island is a defined area between traffic lanes for control
of vehicle movements or for pedestrian refuge. Within an intersection area, a
median or an outer separation is considered to be an island. An island may be
designated by paint, raised bars, mushroom buttons, curbs, guideposts, pavement
edge or other devices and combinations.
CLASSIFICATION AND FUNCTION
Islands frequently serve more than one purpose but may be generally
classified according to their main function as follows:
1. Pedestrian Refuge Islands.
2. Traffic Divisional Islands.
3. Traffic Channelizing Islands.
1. PEDESTRIAN REFUGE ISLANDS
The specific function of a refuge island is to provide a place of safety for
pedestrians who cannot safely cross the entire roadway width at one time because
of changing traffic signals or oncoming traffic.
Refuge Islands are particularly useful at intersections in urban areas where
there is a considerable amount of pedestrian traffic and where heavy volumes of
vehicular traffic make it difficult and dangerous for pedestrians to cross, such
as:
- On multi-lane roadways.
- In large or irregularly shaped intersections.
- At complex signalized intersections to provide a place of safety between
different traffic streams to reduce pedestrian conflicts.
7
2. TRAFFIC DIVISIONAL ISLANDS
The function of divisional islands is to separate opposing traffic; also,
they may be used to separate traffic in the same direction, e.g., to divide
left-turn traffic in a median lane from the through traffic. Divisional Islands
are used to guide traffic around an obstruction within the roadway (such as a
bridge pier) or in advance of an intersection to separate opposing traffic.
Divisional islands may also be located to prevent overtaking and passing at
hazardous points, such as sharp curves or narrow underpasses.
Where Divisional Islands are continuous, they are called medians; the more
important functions are as follows:
- Medians provide an insulating area between opposing streams of moving
traffic.
- Medians provide protection and control of cross and turning traffic.
- Medians provide a refuge for pedestrians.
3. TRAFFIC CHANNELIZING ISLANDS
The primary function of a Channelizing Island is to control and direct a
vehicle operator into the proper channel for his intended route. Channelizing
Islands may be installed to bring about an orderly flow of traffic in areas that
otherwise would be broad expanses of pavement.
Channelization is particularly helpful at streets intersecting at slanting
angles, at 3-leg junctions, and at multileg intersections.
Traffic Channelizing Islands may be provided for separation (and special
control) of turning movements.
Florida Statues Chapter 316 - State Uniform Traffic Control provides
regulations governing driving on divided highways. Section 316.090(2) states "no
vehicle shall be driven over, across, or within any such dividing space,
barrier, or section, except through an opening in such physical barrier or
dividing section or space or at a crossover or intersection as established,
unless specifically authorized by public authority."
SOURCES: 1. Manual on Uniform Traffic Control Devices (MUTCD) by the U.S.
D.O.T.
2. Florida Traffic Laws, Chapter 316 - State Uniform Traffic Control
A roundabout is a circular intersection similar to the "traffic circle" with
which most motorists in this country are familiar. Roundabouts have been used
throughout Europe, Australia, Great Britain and several other countries of the
world for many years. They have only recently been introduced to America as a
means of traffic control, although there are some isolated uses of roundabouts
in this country that have been in place for a number of years.
Roundabouts, when installed according to accepted design principles, offer
reductions in injury crashes, traffic delays, fuel consumption and air pollution
while increasing intersection capacity and enhancing intersection aesthetics.
They have also successfully been used to control traffic speeds in residential
neighborhoods and are accepted as one of the safest types of intersection
design.
The major differences between traffic circles and roundabouts are:
Yield at Entry At roundabouts the entering traffic yields the
right-of-way to the circulating traffic. This yield-at-entry rule keeps traffic
from locking up and allows free flow movement through the intersection.
Deflection The entry geometry and center island of a roundabout
deflect entering traffic to slow the traffic stream and to reinforce the
yielding process.
Flare The entry to a roundabout often flares out from one or two lanes
to two or three lanes at the yield line to provide increased capacity through
the intersection.
There are two basic types of roundabouts (Figure 1):
Conventional roundabout A one-way circular roadway around a curbed
central island for circulating traffic, usually with flared approaches to allow
multiple vehicle entry.
Mini-roundabout A one-way circular roadway around a flush or slightly
raised central island of up to 15 feet in diameter, usually without flared
entries.
Figure 1
Traffic engineers have several reasons why roundabouts are viable traffic
control devices to be considered during the investigation of situations which
may require some form of traffic control. Among the most often considered
reasons are:
1. Safety - Roundabouts have been shown to reduce fatal and injury
crashes by as much as 75% in Australia and 86% in Great Britain. The reduction
in crashes is attributed to slower speeds through the intersection and to a
reduced number of conflict points (Figure 2).
2. Low Maintenance - Roundabouts eliminate maintenance costs
associated with traffic signals which amount to $3,000-$5,000 per year per
intersection. In addition, the cost of electricity is reduced for a savings of
about $1500-$2000 per year per intersection.
3. Reduced Delay - By yielding at the entry rather than stopping and
waiting for a green light, delay is significantly reduced.
4. Increased Intersection Capacity - Intersections with a high volume
of left turns are handled by a roundabout rather than by a multi-phased traffic
signal.
= Conflict Point
Figure 2
5. Reduction of Pollutants - Reduced delay corresponds to a decrease
in fuel consumption and a reduction in air and water pollution.
6. Aesthetics - The central island provides an opportunity to provide
landscaping. Although landscaping requires maintenance, it also provides a
secondary benefit in helping to support adjacent property values.
The correct way to drive a roundabout is simple:
As you approach a roundabout there will be a YIELD sign and a dashed yield
limit line. Slow down, watch for pedestrians and bicyclists, and be prepared to
stop if necessary. When you enter, yield to circulating traffic on the left, but
do not stop if it is clear.
A conventional roundabout will have ONE WAY signs mounted in the center
island. The signs help guide traffic and indicate that you must drive to the
right of the center island. Mini-roundabouts may not have one-way signs if the
center island is not raised. You must still drive to the right of the domed
painted island.
Upon passing the street prior to your exit, turn on your right-turn signal
and watch for pedestrians and bicyclists as you exit.
Left turns are completed by traveling around the central island (Figure 3).
Figure 3
(Adapted from Roundabouts, City of Buenaventura, CA, Traffic Information
Brochure Series, 1995)
Traffic volume counts are basic to all phases of highway development and
operation. No other single reference tells an engineer as much about a road as
the number of vehicles which use it. Traffic volumes are needed for street and
highway project development, financing considerations, project cost-benefit
comparisons, project priority determinations, analyzing, monitoring and
controlling traffic movement on roadways, traffic accident statistics, research
purposes, street and highway maintenance, public information, highway
legislation and other public and private purposes.
Traffic volumes vary from place to place, even along the same highway or
roadway segment. Traffic volumes also vary from hour to hour, day to day, month
to month and year to year. Both location and time elements must be properly
identified and related to one another to develop accurate traffic volume data.
Traffic counts are the major source of traffic data. Traffic counts are very
specific in that they only apply to one location and to the time period for
which they have been obtained. Some of the major types of traffic counts in
general use by engineers are annual counts, peak hour counts, turning movement
counts and classification counts. Annual counts refer to traffic volume
counts that are taken over a period of days throughout the year and converted to
a single number known to engineers as Average Annual Daily Traffic (AADT). This
number is reasonably close to the traffic volume that one could expect to see on
any given day of the year. These volume counts are used for a number of
engineering, economic and public purposes:
As a yardstick for evaluating present highway problems
As a criterion for safety evaluation
As a basis for planning and design estimates
As a basis for establishing need and priorities
As a reference for public information purposes
As a reference for other traffic volume computations
Peak hour counts are traffic volume counts taken during the time
period of the day most likely to produce the highest volumes during any
particular 24-hour period. For instance, the most common peak hour counts of
interest to engineers are those that occur in the morning and afternoon. These
usually occur around the times that most people are traveling to and from work;
however, there are times when the peaks occur at less obvious times. These peaks
may be due to a large employer having a staggered starting or quitting time, a
school or college, or some other out-of-the-ordinary occurrence. The traffic
engineer needs to have this information to properly evaluate the impact of this
traffic pattern on the roadway network. Among the uses for this type of volume
count are:
As a capacity consideration
For traffic signal system operations
As an aid to determining appropriate use of traffic control devices
Turning movement counts are taken at intersections to determine the
actual movement of traffic through the intersection. Traffic engineers and
others have a number of uses for these counts:
For roadway planning and alignment studies
For intersection design
For traffic signal system design
For evaluating traffic volume impacts
Classification counts are just a little different from simple traffic
volume counts. In addition to determining the numbers of vehicles passing a
given point on the roadway, classification counts also separate the traffic
stream into its vehicle-type components and/or speed components; that is, how
many passenger cars, how many trucks, how many vehicles with trailers, etc., and
the variations in speed of the traffic stream. This data is very important to
engineers for a variety of reasons:
As a means of determining percentages of trucks, buses, etc. with respect to
the overall traffic stream
For neighborhood traffic calming studies with respect to "cut-through"
traffic
As an aid in speed studies
For determining the appropriate use of traffic control devices
The foregoing discussion of traffic volume counts is an introduction to what
this data is and why it is important to engineers, planners and the public.
Traffic volume count data is one of the basic resources in determining the most
efficient use of our limited tax revenues for streets and highways and
supporting project selection decisions.
Traffic engineers compare the existing conditions against
nationally accepted minimum standards established after many years of studies
throughout the country. At intersections where standards have been met, the
signals generally operate effectively with good public compliance. Where not
met, compliance is generally reduced resulting in additional hazards.
'HIGHWAY SIGNS' ON
TRAFFIC SAFETY?
PROPERTY OWNERS SHOULD KEEP VEGETATION TRIMMED to insure
that good intersection and driveway sight distance is provided and that traffic
control signs are visible.
Advance Warning Area - tells traffic what to expect.
Regulatory Signs are typically rectangular in shape with the
long dimension vertical. The standard color scheme is black lettering on a
white background. A red circle with a diagonal slash may be used in
conjunction with a black diagram to indicate a prohibited maneuver. Red
is used as a predominant color for STOP, YIELD, DO NOT
ENTER and WRONG WAY signs.
Driveways Per Mile Crashes Per Million Vehicle Miles
Crash Rate Per Million Vehicle Miles
Intersection Type Crashes Per Million Entering Vehicles
Movement Number of Crashes % of Total
ITEM APPROX. COST
Total Parking Spaces Required # of Handicapped Total Parking Spaces Required # of
Handicapped
LAND USE/BUILDING TYPE (ITE CODE) AVERAGE WEEKDAY VEHICLE TRIP ENDS NO. OF
State Rural Principal Arterial County Urban Extension Major Collector
Urbanized to Urbanized w/Arterial Termini Principal Arterial
BOTH APPROACHES OF HIGHER VOLUME APPROACH
I. PLANNING V. PAVEMENT DESIGN, CONSTRUCTION & MAINTENANCE
GENERATOR % PASSER-BY TRIPS (% OF SITE TRAFFIC)
EFFICIENT
TRANSPORTATION SYSTEM?
SUGGESTED IMPACT STUDY AREA RADII (MILES)
ELEMENT RECOMMENDED ALLOWABLE
Penalty 1st Conviction 2nd Conviction 3rd Conviction
Measurement Multiply By To Obtain
The FDOT Greenbook, Table III-2 presents the height of various types of design vehicles as
shown below: Design Vehicle Height
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