We've all had it happen at some point behind the wheel, stuck behind a big rig on the highway as it tries to pass another vehicle.
ABC15 received several complaints from viewers, frustrated by trucks which use the left lane on the highway. So we took your concerns to DPS and also dug into state law.
According to Arizona law, all drivers are required to move to the right, except to pass. There are some exemptions, such as when construction closes part of the roadway.
"The law applies across the board," said DPS Trooper Kameron Lee. "For semi-trucks or passenger cars. You can use that left lane to pass, and that is it. Then you move back over to the right."
Trooper Lee told ABC15 authorities are looking for violators, especially along busy corridors between Phoenix and Flagstaff, as well as between Phoenix and Tucson.
"One of the things we want to make sure that happens is traffic keeps flowing," Lee said. "If traffic is moving and not stopping, we're going to have fewer accidents. That's the biggest concern for us."
According to DPS, troopers have issued 68 citations and 1,188 warnings related to this in 2018.
According to Arizona law:
28-721. Driving on right side of roadway; driving on the shoulder; 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.
C. In an age-restricted community that is located in an unincorporated area of a county with a population of more than three million persons, a person may drive a golf cart or a neighborhood electric vehicle on a paved shoulder that is adjacent to a roadway or as close as practicable to the right-hand curb or edge of a paved roadway if there is no delineated paved shoulder.