What is the purpose of the yellow change interval at traffic signals?

The purpose of the yellow change interval at traffic signals is to allow vehicles to stop safely. This interval serves as a warning that the signal is about to change from green to red, providing drivers an opportunity to make a decision on whether to continue through the intersection or come to a stop. The timed duration of the yellow light is critical because it is determined based on the speed limit of the road and the distance needed for vehicles to decelerate safely when stopping.

This interval not only enhances safety by preventing abrupt stops that could lead to rear-end collisions but also ensures that vehicles approaching the signal have a clear indication of the impending change. This design intention supports the overall objective of traffic signal operations, which is to regulate traffic flow effectively while minimizing accidents and promoting safe driving behaviors.