Arizona commercial vehicle weight limits follow the federal Interstate standard of 80,000 lbs gross, 20,000 lbs per single axle, and 34,000 lbs per tandem axle group. The federal bridge formula (23 U.S.C. 127) applies on all routes. No seasonal weight restrictions on Interstate highways. Oversize and overweight permits are available from AZ DOT for loads exceeding standard limits. Verify current road-specific postings with the Arizona DOT before routing heavy loads.
The federal bridge formula limits the weight on any group of axles based on the distance between the outermost axles in the group. It applies in Arizona on all routes where federal standards apply.
W = maximum weight in lbs · L = axle spacing in feet · N = number of axles
ADOT issues oversize/overweight permits for loads exceeding standard limits. Single-trip permits for one-time movements. Annual permits for qualifying repetitive moves. LCV permits required for doubles/triples beyond standard 80,000 lb operations. Superload permits for extreme weights require engineering review and pre-approved routing. Apply through the ADOT permit system at azdot.gov.
Apply for Arizona OS/OW Permit →On standard Interstate highways in Arizona, the maximum gross vehicle weight is 80,000 lbs — matching the federal standard. However, Arizona authorizes Long Combination Vehicles (LCVs) on designated routes at up to 129,000 lbs gross weight. LCV operations require a T endorsement on the driver's CDL and an ADOT permit.
No. Arizona does not impose seasonal spring weight restrictions. The desert climate means Arizona roads do not experience freeze-thaw pavement damage that drives spring restrictions in Northern states. This makes Arizona a reliable year-round corridor for heavy freight on I-10, I-17, I-40, and I-8.
Arizona designates specific Interstate routes for Long Combination Vehicles (LCVs) — double and triple trailer combinations up to 105 feet and 129,000 lbs gross. To operate an LCV, drivers need a Class A CDL with T endorsement, and carriers must obtain an ADOT LCV permit. LCV operations are restricted to daylight hours on some routes. Contact ADOT for current designated routes and permit requirements.
ADOT issues oversize/overweight permits through its Special Use Permits office. Apply through the ADOT permit system at azdot.gov. Single-trip permits cover one-time movements of loads exceeding legal limits. Annual permits are available for qualifying routine operations. Superload permits for extreme weights require engineering review and route pre-approval.
Arizona's tandem axle limit is 34,000 lbs on Interstate highways — matching the federal standard. Tridem configurations are allowed up to 42,000 lbs. On LCV-designated routes with applicable permits, total axle group weights may differ — consult the specific LCV permit conditions.
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Disclaimer
The information on this page is compiled from publicly available government sources and is provided for general informational purposes only. TruckRadar is an independent search engine — we are not affiliated with any government agency and this content does not constitute legal or compliance advice. Regulations change frequently; always verify current requirements directly with the official source before making compliance decisions.
Official source: Arizona AZ Department of TransportationLast reviewed: 2026-04