ARS 28-721. Driving on right side of roadway; exceptions
A. On all roadways of sufficient width, a person shall drive a vehicle on the right half of the roadway except as follows:
1. When overtaking and passing another vehicle proceeding in the same direction under the rules governing the movement.
2. When the right half of a roadway is closed to traffic while under construction or repair.
3. On a roadway divided into three marked lanes for traffic under the rules applicable on the roadway.
4. On a roadway designated and signposted for one-way traffic.
B. On all roadways, a person driving a vehicle proceeding at less than the normal speed of traffic at the time and place and under the conditions then existing shall drive the vehicle in the right-hand lane then available for traffic or as close as practicable to the right-hand curb or edge of the roadway, except when overtaking and passing another vehicle proceeding in the same direction or when preparing for a left turn at an intersection or into a private road or driveway.
ARS 28-723. Overtaking a vehicle on the left
The following rules govern the overtaking and passing of vehicles proceeding in the same direction:
1. The driver of a vehicle overtaking another vehicle proceeding in the same direction shall pass to the left of the vehicle at a safe distance and shall not again drive to the right side of the roadway until safely clear of the overtaken vehicle.
2. Except when overtaking and passing on the right is permitted, the driver of an overtaken vehicle shall give way to the right in favor of the overtaking vehicle on audible signal or blinking of head lamps at nighttime and shall not increase the speed of the overtaken vehicle until completely passed by the overtaking vehicle