Red Clearance Interval duration is generally how long?

Red Clearance Interval duration is generally how long?

• A. 1-2 seconds
• B. 3-6 seconds
• C. 5-7 seconds
• D. 0.5-1 seconds

Answer: (A)

The red clearance interval is the brief all-red period that follows a green phase, giving conflicting traffic a safe moment to clear the intersection before the next phase can start. This window is about one to two seconds in general practice. That duration strikes a balance between safety and efficiency. It provides enough time for vehicles already entering the intersection, and any turning movements, to clear the crosswalks and lanes, reducing the chance of right-angle or left-turn conflicts when the next phase begins. At the same time, it’s short enough to avoid adding unnecessary delay to the overall signal cycle. In practice, engineers adjust this interval based on intersection geometry and speeds, but the common, broadly applicable range is about one to two seconds.

The red clearance interval is the brief all-red period that follows a green phase, giving conflicting traffic a safe moment to clear the intersection before the next phase can start. This window is about one to two seconds in general practice.

That duration strikes a balance between safety and efficiency. It provides enough time for vehicles already entering the intersection, and any turning movements, to clear the crosswalks and lanes, reducing the chance of right-angle or left-turn conflicts when the next phase begins. At the same time, it’s short enough to avoid adding unnecessary delay to the overall signal cycle. In practice, engineers adjust this interval based on intersection geometry and speeds, but the common, broadly applicable range is about one to two seconds.