Staying In Your Lane
A.R.S. 28-729 — as nearly as practicable entirely within a single lane, and the center lane of three
Two duties. On a roadway divided into two or more clearly marked lanes, a person drives as nearly as practicable entirely within a single lane, and does not move from it until the driver has first ascertained that the movement can be made with safety.
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.
The center lane of three. On a roadway divided into three lanes, a person does not drive in the center lane except when overtaking and passing where the roadway is clearly visible and the center lane is clear for a safe distance, preparing for a left turn, or where it is allocated to the vehicle's direction and signposted.
Signs. Official signs may direct slow moving traffic to a designated lane, or designate lanes by direction, and drivers obey them.
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 Arizona attorney.
Sources for this section (1)
- A.R.S. 28-729 — Driving on roadways laned for traffic
Legal information, not legal advice. Verified as of September 2026. Applying it to a particular situation is the work of a licensed Arizona attorney.