Traffic signals improve the safety and mobility of both pedestrians and vehicular traffic. They can also save energy and money by providing for more efficient use of road space.
Signals are installed only if they meet certain federal guidelines called “warrants”. Meeting one warrant does not necessarily require a traffic signal to be installed at an intersection.
Design
Traffic Loop Contractors increase the capacity of an intersection and provide for a more efficient movement of traffic. When properly timed, they reduce accidents and improve the flow of both pedestrians and vehicular traffic. They also serve to reduce the amount of time drivers spend waiting at stop signs and red lights.
The design process starts by evaluating the intersection. We look at the Accident Index System for that location as well as individual accident reports. This information is compared to Federal guidelines that determine if the area warrants a traffic signal.
Next, we prepare a preliminary signal layout. This includes determining the type and location of signal heads, detectors, power supply assemblies, and signal controllers. We also specify the number and sizes of conduit runs and pull boxes. Finally, we determine appropriate left turn phasing control and indications and verify vehicle turning paths. Then we begin the engineering process that will result in a final signal layout.
Installation
Traffic signals assign right-of-way to opposing traffic movements and therefore profoundly influence the flow of traffic at an intersection. They also provide guidance to pedestrians on when and how to cross busy streets. Traffic signals reduce accidents by regulating traffic movement and removing unregulated interaction between vehicles at intersections.
Traffic signal installation requires extensive investigation and evaluation. Using a process called warrant analysis, engineers carefully examine traffic conditions at every intersection where a signal may be considered. The data includes the number of accidents, vehicle speeds, traffic volumes and other factors at that location.
The goal is to determine if a signal would solve a specific problem. In addition, the engineer must weigh that against other problems a signal might create such as rear-end collisions, delay, disobedience and diversion of traffic to local residential streets. Often, less-intrusive forms of control like stop or yield signs are tried and found ineffective before a traffic signal is considered.
Maintenance
Traffic signals are complex, electrically operated devices that assign the right-of-way to various vehicular and pedestrian movements. They are used to reduce intersection accidents, increase safety, and improve traffic flow. They are often found on arterial roads at intersections with other arterials, collector or stub roads. They can also be found on some expressways in busy settings.
National standards help assure that traffic signals are installed only where they will benefit the traveling public and reduce accidents, congestion and air pollution. Before a signal can be installed, an engineer must thoroughly review the intersection and collect data on traffic movement, observe traffic patterns and analyze three years of accident history.
Traffic signal maintenance consists of the inspection, repair and replacement of traffic signal controllers, pedestrian signals, conflict monitors, cabinets and their equipment, poles, and span wire. Maintenance activities are typically performed by contracted traffic signal maintenance specialists. Maintenance work can be performed on a preventative or emergency basis.
Repair
Traffic Loop Contractor help direct traffic flow and improve safety for pedestrians. Traffic signals also reduce the frequency and severity of accidents by assigning rights-of-way to opposing movements.
Signals must be retimed from time to time to optimize their performance, which can be complicated and costly. Some localities have not retimed their signals in 20 years, according to the Federal Highway Administration (FHWA).
In general, FHWA advocates that “basic signal timing is a critical element of a traffic system” but emphasizes the need for cost control. Signal-timing work is relatively inexpensive compared to other capital projects, but it still requires investment, says Pamela Crenshaw, an FHWA transportation specialist.
Drivers should report any problems with traffic signals, such as a malfunctioning light, to their city or county’s public works or transportation department. Drivers should be sure to provide the street and cross streets of the intersection, as well as the day and time they observed the problem.
