How is the placement of a Traffic Signal Determined?

Traffic signal requests are often received from community groups and individual citizens.  Metro Traffic engineers follow up such requests with a study of the intersection to determine whether a traffic signal installation is justified. To conform with national standards, the signal must meet specific criteria found in the “Manual of Uniform Traffic Control Devices”, published by the Federal Highway Administration. This justification study takes into account:

• The number of vehicles and pedestrians using the intersection.
• The intersection’s accident history.
• The intersection’s proximity to major traffic routes, other traffic signals and schools. 
• Unusual conditions such as road curvature.

Traffic patterns can dramatically change in and around an intersection when a signal is installed. When evaluating a potential traffic signal location, full consideration of the benefits and disadvantages of signalization must be reviewed.