Traffic Division Q & A
| Stop Signs | Streetlights | Speed Limits | Miscellaneous |
Q. How do I report a traffic signal problem?
A. For your safety, the Engineering Department tries to ensure that all of the traffic signals are in operable condition. If you notice an inoperable traffic signal or burned out bulb, please report it to the Engineering Department at (772) 871-5177.
Q. Why does it take so long for the signal to change?
A. Traffic engineers attempt to move the greatest amount of vehicles in the shortest amount of time. Signals are usually programmed so that each intersection is �timed� to work with other intersections. While a small amount of cars are waiting for the signal to change on the minor street, a larger amount of vehicles are permitted to move along on the major street. Based on traffic volume data (which changes from day to day), it is sometimes better to hold the minor street RED for a specific amount of time causing traffic to stack up, while allowing the greater number of vehicles to travel through Green signals on the major street.
Q. Why doesn't the traffic signal change when I push the Pedestrian Button?
A. Traffic signals are programmed to change at certain intervals. Pushing the pedestrian button informs the signal controller that you are waiting to cross the street. At the next programmed interval the traffic signal will change and allow enough time for you to cross safely.
Q. What are the 'warrants' for a traffic signal?
A. 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 one of the warrants presented in the MUTCD. 1
Q. Won't a traffic signal reduce crashes at our intersection?
A. Traffic signals don't always prevent crashes. In many instances, the total number of crashes and injuries increase after they're installed. The most common results of the installation of a traffic signal are a reduction in right-angle collisions but an increase in total crashes, especially the rear-end type collisions. Traffic engineers compare the existing conditions against nationally accepted minimum standards established after many years of studies. 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. 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.
Q. Can you synchronize the traffic signals along a particular roadway?
A. Traffic signal synchronization is a method of timing groups of traffic signals along an arterial roadway to provide smooth movement of traffic with minimal stops. The quality of the resulting progression is a function of the spacing of the signals, the prevailing speeds, the amount of traffic coming in and out of driveways between traffic signals, the uniformity of intersection sizes, and the cycle length.
Q. What should a driver do when approaching an intersection in which traffic lights are not working?
A. Florida Statutes, Section 316.1235, state: the driver of a vehicle approaching an intersection in which the traffic lights are inoperative shall stop, except when directed to proceed by a police officer.
The driver shall stop:
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at a clearly marked stop line, (or if none,)
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before entering the crosswalk on the near side of the intersection, (or if none, then)
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at the point nearest the intersecting roadway where the driver has a view of approaching traffic on the intersecting roadway before entering the intersection.
After having stopped, the driver shall yield the right-of-way to any vehicle which has entered the intersection from another highway, or which is approaching so closely as to constitute an immediate hazard during the time when the driver is moving across or within the intersection. The traffic signal malfunction should be reported to the police as soon as possible.1
Q. How do 'pedestrian' signals work?
A. A pedestrian signal allows a safe way for pedestrians to cross the street at signalizedintersections. 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.1
Streetlights / Signs
Streetlights
Q. How do I report a streetlight problem?
A. If you need to report a streetlight out it is first important what agency is responsible for maintaining the streetlight. Click here to view examples. Typically, streetlights in residential areas and located on concrete or wood poles are maintained by FPL. To assist FPL in identifying the streetlight, please provide the pole number and closest intersecting streets. Please click on https://app.fpl.com/secure/forms/streetlight.shtml to report the outage under "Street Light."
The City maintains streetlighting and pedestrian lighting on the major roadways throughout the City. For example, Port St. Lucie Boulevard, Lennard Road, Gatlin Boulevard, etc. To report a streetlight out, please call the Engineering Department (772-871-5177).
Q. Why can't a stop sign be installed to stop speeding on my street?
A. 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.1
Q. Why can't we have a 4-way stop to reduce crashes?
A. 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 installation of multi-way stop signs must first meet warrants as specified in the Manual of Uniform Traffic Control Devices MUTCD Section 2B.07 These warrants include traffic volumes, approach speeds, site distance, and crash history. Stop signs should not be viewed as a cure-all for solving all safety concerns.1
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.
Q. Why are those stop signs so high?
A. 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 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."
Q. "Why must signs be so high?"
A. One major reason is the improved visibility that results. In urban areas, parked cars and other obstruction 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 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.1
Q. Won't a "children at play" sign help protect our children?
A. 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 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.
Q. How do I get Blind/Deaf Person Area signs installed on my street?
A. Blind or Deaf Person Area signs can be installed on streets or in neighborhoods where a blind or deaf person lives. These signs are meant to alert drivers that a visually or hearing impaired person lives in the area and may be walking in the neighborhood. The engineer with whom you speak will ask you to send documentation of the impairment. To request a "Blind or Deaf Person Area" sign, call the Engineering Department at (772) 871-5177 or email your request to info@cityofpsl.com.
Q. Why not lower the speed limit to reduce accidents?
A. Many years of research have proven that lower speed limits do not appreciably alter traffic speeds. Tests have been conducted where the numbers on speed signs have been arbitrarily raised and lowered to see what effect this would have on traffic. Speed checks taken before and after the change indicated that speeds remained nearly the same regardless of the number on the sign. These studies indicate the validity of the assumption that drivers select their speeds intuitively based on the environment around them and the speeds with which they feel comfortable and safe.
Other research studies have shown that speed limits set below the reasonable speed of the majority do not have significant effects on a reduction in the number of accidents on a road. In fact, accidents may increase with unreasonably low speed limits.
Q. How are speed limits established?
A. In Florida, speed limits are set by Florida Statutes, Title XXIII, Chapter 316 that 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.
Q. What is the difference between the white and yellow speed sign?
A. Speed Limit signs with a black message on a white background are regulatory signs; 
while Speed Advisory signs with a black message on a yellow background are warning signs.Regulatory signs are used to impose legal restrictions applicable to particular locations and the restrictions are not enforceable 
without these signs (i.e., Speed Limit signs). Warning signs are used to call attention to hazardous conditions, actual or potential, which otherwise would not be readily apparent, (i.e., Advisory Speed signs around a curve). The established Advisory Speed at a curve is based on the safe and comfortable speed for the drive.
Q. What can a pedestrian do to reduce pedestrian crashes?
A. Each year for the last five years, there were more than 600 pedestrian fatalities and over 7,000 pedestrian injuries in Florida. Statistics from 1985 indicated a pedestrian fatality rate of 5.71 per 1,000 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 dart-outs
Mutiple Lanes crossing
Intersection Dash
Vehicle Turn/Merge
Vendor - Ice Cream Truck and Backup up
Here are some tips to avoiding car/pedestrian mishaps:
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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.
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Walk facing oncoming traffic - when there are no sidewalks, walk near the curb or off the road if necessary.
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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 that you are completely safe in a crosswalk. Don't cross at mid-block because "jaywalking" is dangerous and against the law.
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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.
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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.
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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.
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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.
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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 these tips will greatly improve your chances of safely walking your estimated lifetime average of 75,000 miles.
Q. What are traffic volume counts and what are they used for?
A. 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 developments, 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 use for a number of engineering, economic and public purposes:
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As a yardstick for evaluating present highway problems
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As a criterion for safety evaluation
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As a basis for planning and design estimates
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As a tool for establishing need priorities
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As a reference for public information purposes
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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:
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As a capacity consideration
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As a design tool for traffic signal system operations
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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:
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As a tool for roadway planning and alignment studies
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As a tool for intersection design
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As a tool for traffic signal system design
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As a tool 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 speed components; that is, how many passenger cars, how many trucks, how many vehicles pulling trailers, etc., as well as the variations in speed of the traffic stream. As one might very well imagine, this data is very important to engineers for a variety of reasons:
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As a means of determining percentages of trucks, buses, etc. with respect to the overall traffic stream
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As a tool in neighborhood traffic calming studies with respect to "cut-through" traffic
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As an aid in speed studies
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As a tool in 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.1
1-Reference from the Institute of Transportation Engineers Florida Section District 10, Traffic Information Program Series