Which interval lasts longer?

Which interval lasts longer?

• A. Red Clearance Interval
• B. All intervals are the same
• C. Yellow Clearance Interval
• D. Green Interval

Answer: (C)

In signal timing, there are safety margins built into the transition periods so that vehicles can safely clear the intersection as the light changes. The Yellow Clearance Interval is the time allocated to the moment when yellow is shown and drivers are still decelerating or finishing turns before red fully stops opposing traffic. It’s deliberately longer because it must accommodate reaction times, varying speeds, and the distance needed for vehicles already in the intersection to clear safely. That safety-focused extension often makes the yellow clearance interval longer than the basic green or red phases, which are driven more by throughput and the need to stop or go. So, the interval that lasts longer is the Yellow Clearance Interval.

In signal timing, there are safety margins built into the transition periods so that vehicles can safely clear the intersection as the light changes. The Yellow Clearance Interval is the time allocated to the moment when yellow is shown and drivers are still decelerating or finishing turns before red fully stops opposing traffic. It’s deliberately longer because it must accommodate reaction times, varying speeds, and the distance needed for vehicles already in the intersection to clear safely. That safety-focused extension often makes the yellow clearance interval longer than the basic green or red phases, which are driven more by throughput and the need to stop or go. So, the interval that lasts longer is the Yellow Clearance Interval.