What does cycle length measure in a traffic signal?

What does cycle length measure in a traffic signal?

• A. The sum of all red times in the cycle.
• B. The time from green to green for a single approach units.
• C. The time between successive green starts.
• D. The total time to complete one full sequence of phases.

Answer: (D)

Cycle length is the duration of one complete sequence of signal phases at an intersection. It’s the total time from when the cycle starts until the signal returns to the same configuration and is ready to begin again. This includes all phases for every approach—green, yellow, red and any all-red clearance intervals. So the cycle length is the total time to complete one full sequence of phases. In practice, the time between successive green starts on a given approach is related, but the defining measure is the full cycle across all phases.

Cycle length is the duration of one complete sequence of signal phases at an intersection. It’s the total time from when the cycle starts until the signal returns to the same configuration and is ready to begin again. This includes all phases for every approach—green, yellow, red and any all-red clearance intervals. So the cycle length is the total time to complete one full sequence of phases. In practice, the time between successive green starts on a given approach is related, but the defining measure is the full cycle across all phases.