Each year, the City receives many inquiries concerning the installation of new traffic signals or left turn arrows. Engineering studies are done to determine where new devices are needed.
Our review may include an examination of:
Traffic signals and other traffic calming devices can be requested through the Traffic Engineering Division. Contact us at (520) 791-4259.
A list of requested improvements is compiled during the year. Signal and arrow studies generally begin after the first of each year and take several months to complete. Studies are done during this time of the year because that is when traffic conditions are generally busiest.
Traffic crews conduct an engineering study to see if the location meets the State and Federal warranting criteria. This engineering study is an information gathering process. For new traffic signals, traffic volume, the speed that traffic is flowing, the amount of pedestrian activity, accident history and the distance the proposed new signal location is away from adjacent signals is gathered.
For left turn arrow requests at existing signals, turning and opposing volumes are counted during peak hours, the delay per turning vehicle is calculated, total turning delay is determined and accident history is reviewed.
Note: The Federal Manual on Uniform Traffic Control Devices (MUTCD) states: "The satisfaction of a traffic signal warrant or warrants shall not in itself require the installation of a traffic control signal."
Traffic control signals are not the solution to every traffic problem. When properly used, traffic control signals are valuable devices for the control of vehicular and pedestrian traffic. They assign the right-of-way to the various traffic movements and thereby profoundly influence traffic flow.
Traffic control signals that are properly designed, located, operated, and maintained will have one or more of the following advantages:
Traffic control signals are often considered a panacea for all traffic problems at intersections. This belief has led to traffic control signals being installed at many locations where they are not needed, adversely affecting the safety and efficiency of vehicular, bicycle, and pedestrian traffic.
Improper or unjustified traffic control signals can result in one or more of the following disadvantages: