Evaluation of Change and Clearance Intervals Prior to the Flashing Yellow Arrow Permissive Left-Turn Indication
When a separate lane is provided for left-turning vehicles, the interval during which drivers
turn can be described as either protected or permissive. In a protected left-turn movement,
the left-turning driver has the exclusive right-of-way and faces no other (legal) conflicts.
In a permissive left-turn movement, the left-turning driver may turn only after yielding
to other conflicting movements, including vehicles, pedestrians, and/or bicycles.
NCHRP Web-Only Document 394: Evaluation of Change and Clearance Intervals Prior to the Flashing Yellow Arrow
Permissive Left-Turn Indication,
develops recommendations for the use of steady yellow arrow change and steady red arrow
clearance intervals.
This Summary Last Modified On: 3/27/2024