Traffic signals are usually warranted based on minimum traffic volumes during eight hours of a typical weekday. These minimum volumes, or "warrants," vary depending on the speed of the roadway and the number of approach lanes.
For a signal to be considered, it needs to meet the necessary warrants and be justified by an engineering study. Engineering studies review factors such as access and distance to nearby signals, lane geometry, and future road plans. If all the necessary conditions are satisfied and funding is available, a signal installation may be considered.