Staying In Your Lane
MCL 257.642 — as nearly as practicable entirely within a single lane, and the extreme right lane on four lanes or more
Within a single lane. On a roadway divided into 2 or more clearly marked lanes, a vehicle is driven as nearly as practicable entirely within a single lane and is not moved from it until the operator has first ascertained that the movement can be safely made.
The standard the section writes is as nearly as practicable entirely within a single lane, with any move out of the lane waiting until it can be made safely. How courts apply those words to a brief touch of a line is not on this page.
Four lanes or more, two ways. On a roadway divided into 4 or more lanes with two way traffic, a vehicle is operated within the extreme right hand lane except when overtaking and passing, and does not cross the center line except when making a left turn.
The center lane of three. On a roadway divided into three lanes with two way traffic, a vehicle is not driven in the center lane except when overtaking and passing with the center lane clear for a safe distance, when preparing for a left turn, or where the center lane is allocated to the vehicle's direction by official traffic control devices.
HOV lanes. A lane designated and marked as an HOV lane is reserved during the periods indicated for buses and HOVs, except for emergency vehicles, law enforcement vehicles, buses and motorcycles.
Whether a particular drift over a line was a violation, or a reason for a stop, depends on the facts and on how the courts read the words as nearly as practicable, and is a question for a licensed Michigan attorney.
Sources for this section (1)
- MCL 257.642 — Roadway divided into 2 or more marked lanes; applicable rules
Legal information, not legal advice. Verified as of September 2026. Applying it to a particular situation is the work of a licensed Michigan attorney.