The purpose of a traffic signal is to assign right-of-way to opposing movements of traffic at an intersection. As such, it may be necessary to install a traffic signal if the traffic volume increases and four-way stop signs do not lessen problems. However, improperly placed traffic signals can cause an increase in traffic accidents, particularly rear end collisions. Additionally, pedestrians can gain a false sense of security from crosswalks and red lights, which may result in an increase in pedestrian accidents. Before installing a traffic signal at an intersection, traffic engineers have to evaluate the following questions:
- Does the volume of vehicles entering an intersection create confusion or congestion?
- Is there so much traffic on main streets that it may be dangerous for traffic on side streets to cross? Are accidents the result of this condition?
- Is there an increasing demand for pedestrians to cross main streets?
- Does the number of school children crossing a busy street create confusion, congestion, or hazardous conditions?
- Will the installation of a signal reduce overall congestion?
- Does the accident history indicate that a signal will reduce the number of accidents at an intersection?
Traffic engineers use national standards to evaluate an intersection that may need a traffic signal. Properly placing traffic signals will decrease accidents and improve traffic flow. Questions should be directed to the Strategic Enforcement and Prevention Unit at 630-823-5481.