How long should traffic signal Yellow Change intervals be, as specified by the Manual on Uniform Traffic Control Devices?

The correct response indicates that the Yellow Change interval should be in the range of 2 to 5 seconds long. This time frame is based on guidelines established to ensure adequate and safe operation of traffic signals.

The purpose of the Yellow Change interval is to provide a warning to drivers that the signal is about to change to red, allowing them sufficient time to clear the intersection safely if they are already in it or to stop safely if they are approaching. The 2 to 5 seconds range is tailored to typical vehicle speeds and conditions, ensuring it remains effective in most driving scenarios.

Factors considered in determining this interval include the speed limit in the area, the type of intersection, and the traffic flow. This flexibility allows for different conditions while maintaining safety. For instance, at higher speeds, a longer Yellow Change interval might be necessary; however, the maximum duration is held within the recommended limits to prevent confusion or improper use of the signal.

Thus, the choice in the 2 to 5 seconds range is recognized as appropriate for accommodating a variety of situations and ensuring that drivers have enough time to react adequately to the changing light.