Staying In Your Lane
G.L. c. 89, § 4A — entirely within a single lane, and no move until it can be made with safety
Two duties. When a way is divided into lanes, the driver drives so the vehicle is entirely within a single lane, and does not move from it until first ascertaining that the move can be made with safety.
Entirely. Unlike the as nearly as practicable standard in many states, this section's words are entirely within a single lane. How courts apply them to a brief touch of a line is not on this page.
Motorcycles. Motorcyclists may not ride abreast of more than one other motorcycle, ride single file when passing, and may not pass another motor vehicle within the same lane except another motorcycle.
Other sections, and how courts read these words, are not on this page. Whether a particular drift was a violation in a particular case is a question for a licensed Massachusetts attorney.
Sources for this section (1)
- G.L. c. 89, § 4A — Driving within a single lane
Legal information, not legal advice. Verified as of September 2026. Applying it to a particular situation is the work of a licensed Massachusetts attorney.