AZ SB1291

Amends Arizona Revised Statutes section 28-1100 to modify gross weight restrictions for heavy-duty vehicles.

Increases the allowable gross weight exemption for vehicles equipped with idle reduction technology from 400 pounds to 550 pounds or the weight of the idle reduction technology, whichever is less.

Expands the natural gas vehicle weight exemption to include battery electric and hydrogen fuel cell electric vehicles, allowing up to 82,000 pounds gross weight or the weight difference between alternative fuel systems and comparable diesel systems, whichever is less.

Maintains existing gross weight limits for standard vehicles: 20,000 pounds per axle, 34,000 pounds for tandem axles, and 80,000 pounds for five or more axle combinations.