Traffic Signal Installation

Will a traffic signal always make an intersection safer?
Traffic signals don’t always prevent accidents. Accidents and serious injuries may actually increase after they are installed. Quite often, right angle collisions are reduced by traffic signals, while the total number of collisions, particularly the rear-end type, increases.

Occasionally, signal installation results in an increase in pedestrian accidents. Many pedestrians feel secure with a painted crosswalk and red light between them and approaching vehicles. However, drivers are not always so quick to recognize these "barriers".

When will a traffic signal help more than hurt? To answer this question correctly, Traffic Engineers must first ask and answer a number of other questions:

  • Are there so many cars on both streets that signal control is necessary to clear up driver confusion or relieve traffic congestion?
  • Is main street traffic so heavy that drivers on the side street try to cross when it is unsafe?
  • Are there lots of pedestrians crossing a busy, main street?
    Does this result in confusing, congested, or hazardous conditions?
  • Are there so many school children crossing the street that special controls are necessary for their protection? If so, is a traffic signal the best solution?
  • Does an intersection’s accident history indicate that a signal will reduce the possibility of a collision?
  • Will a traffic signal at this location help improve traffic flow and help drivers maintain a uniform pace without stopping unnecessarily?
  • Can gridlock with a nearby signal be avoided?
  • Is there a combination of the above conditions which indicates that a traffic signal will be an asset rather than a liability to safety?

To help answer these questions, Traffic Engineers compare existing conditions against minimum guidelines established from many years of study throughout the country. Where these guidelines (often called "warrants") are met, traffic signals generally operate effectively with good driver compliance. Where the guidelines are not met, driver compliance is reduced and more traffic hazards result.

A traffic signal installed at the right location can improve the flow traffic and reduce accident. However, a traffic signal placed unnecessarily or for the convenience of a few will be a source of danger and annoyance for all who use the intersection: pedestrians and drivers alike.

The Traffic Engineering Department conducts traffic signal studies at intersections around the City of Amarillo on a regular basis using the guidelines discussed above. If you feel there is an intersection which may benefit from traffic signal control, please call us at (806)378-4218 or email us. You may also visit our offices in Room 204 of City Hall at 509 E. 7th Ave, or write us at P.O. Box 1971, Amarillo, Texas, 79105-1971.

A Public Awareness Program