Legal Weight Limits

Arizona follows the standard 20,000 lbs per single axle, 34,000 lbs per tandem, and 80,000 lbs gross (for 5 axles) limits on most highways. These limits include any enforcement tolerances – meaning Arizona does not grant a general buffer above 80,000 lbs without a permit. However, Arizona does allow trucks to adjust axle group weights if only axle (not gross) limits are exceeded: an officer will permit shifting the load if an axle is heavy. If after shifting, the excess on that axle was ≤2,500 lbs, the driver will not be cited. This effectively gives a small chance to correct axle distribution. Apart from that, Arizona’s legal weights mirror federal limits and the Bridge Formula, which is enforced for any combination over 80k or with axles spaced unusually.

Fine Structure

Arizona’s overweight fines are specified in Arizona Revised Statutes §28-1101 and are graduated by the pounds over limit. Notably, if the excess weight is 1,000 lbs or less, the fine is only $1 – essentially a token penalty . Beyond that, fines ramp up in brackets:

  • 1,001–1,250 lbs over: $100 minimum fine.
  • 1,251–1,500 lbs: $200 minimum.
  • 1,501–2,000 lbs: $300 minimum.
  • Fines continue increasing roughly $100 for each additional ~250 lbs increment. For example, 3,001–3,500 lbs over is an $840 fine, and 4,001–4,500 lbs over is $1,120.
  • Over 5,000 lbs: $1,400 plus $100 for each 1,000 lbs above 5,000. This works out to about $0.10 per pound over 5,000. For instance, 11,000 lbs over would cost ~$2,000 under that formula.

These fines are civil penalties for a first violation. Arizona also escalates repeat offenses: a second overweight violation within 6 months can be charged as a Class 3 misdemeanor, and a second such misdemeanor within a year upgrades to a Class 2 misdemeanor. Those carry potential jail time (up to 30 days for class 3) in addition to fines, underscoring that habitual overweight offenses are taken seriously. Additionally, if a driver knowingly refuses to stop to be weighed, that carries a $250 civil penalty under §28-1102 (a 2025 amendment, Laws 2025 Chapter 101, changed it from a class 3 misdemeanor), and refusing a portable-scale weighing demanded by a peace officer carries a civil penalty of at least the fine for being over 6,000 lbs. Overall, Arizona’s fine structure starts forgiving (only $1 for ≤1000 lbs over) but becomes expensive as the excess weight grows.

Enforcement Methods

Arizona enforces weight limits through a network of fixed Ports of Entry (weigh stations), numbering around 17, located along the state’s borders and key highway corridors. Commercial vehicles must stop at open ports unless they have pre-clearance via systems like PrePass.

Many stations utilize Weigh-in-Motion (WIM) technology and automated screening to detect overweight or credential issues; compliant trucks receive a green signal to bypass, while those flagged are directed to stop for inspection.

Enforcement also includes portable scales used by ADOT Enforcement & Compliance and DPS Commercial Vehicle Enforcement troopers for random roadside checks on secondary roads or industrial corridors. If a truck is found overweight, officers first attempt to resolve the issue through load shifting; if shifting brings axle weight within 2,500 lb of the limit, no citation is issued. Otherwise, the driver is cited and the vehicle is subject to load off‑loading or permit acquisition before being allowed to proceed.

Arizona monitors and penalizes scale avoidance heavily, pursuing trucks that bypass open scales and issuing civil penalties for refusal to comply. Over the last decade, Arizona has also implemented Truck Screening Systems at rest areas, combining cameras and WIM sensors to screen in‑motion vehicles and focus enforcement only on those with alerts. This “virtual port” approach improves traffic flow while ensuring non‑compliant vehicles are still identified and inspected. Finally, Arizona continues to expand mobile enforcement operations in high‑risk zones like aggregate and concrete haul routes, informed by data showing pockets of overweight activity outside physical weigh stations.