After passing another vehicle on the left, when is there normally enough clearance to return to the right lane?

Correct answer: C. – When you can see the passed vehicle’s headlights in your inside mirror
The Massachusetts manual advises waiting at least until the passed vehicle’s headlights are visible in your mirror before returning right. Signal before moving back and make sure sufficient clearance remains. A driver being overtaken must slow down, stay right, allow the pass, and not increase speed, but the passing driver remains responsible for returning safely.
Source: Massachusetts Driver’s Manual (rev. Apr. 2026) — Ch. 3, “Passing on the Left” and “Being Passed”




