Oversize Load Regulations by State

Maximum Legal Truck Height by State

Maximum legal truck height on the Interstate ranges from 13′6″ in most eastern states to 14′ or 14′6″ across much of the West. Florida caps the lowest at 13′6″; Arizona, Montana, and Texas all allow 14′ before a permit is required.

Anything above the legal limit requires an oversize permit. Pole escort and route survey thresholds vary widely. Some states trigger a front pole escort near 14′6″ to 17′, and written route surveys more commonly kick in at 17′ to 19′. Loads approaching 16′–17′ are often classified as a superload requiring DOT advance notice.

See each state's exact legal height limit in the map or table below. Use the calculator to check the specific heights that trigger permits, pole escorts, route surveys, or superload designations for your route.

Wide Load Pilot Car & Escort Thresholds by State

Maximum legal trailer width on the Interstate is 102″ (8′6″) in every state. Anything wider is classified as a wide load and requires an oversize permit, and in most states a pilot car escort. The width at which the first pilot car is required varies enormously: Arizona triggers one at 11′1″, Florida at 12′1″, Texas at 14′1″ (on divided roads), and Montana not until 16′7″.

A second escort (typically a 2-car front-and-rear configuration) is usually required above 14′, and police escort often kicks in around 16′ or wider. Oversize signs, red flags, and amber warning lights are mandated once the load passes 10′ in most states, and several states restrict wide-load travel to daylight only or prohibit it on major holidays.

See the first width at which a pilot car is required in each state using the map or table below. Use the calculator to check exact escort counts, police requirements, and travel restrictions for your route.

Length Escort Thresholds by State

On the Interstate, most states require a rear escort once the overall combination length (tractor, trailer, and load) passes a set point. That point ranges from 75′1″ in Georgia to 160′ in New York, with most states landing between 90′ and 125′. It is keyed to overall length, not trailer length alone.

A few states are exceptions. Georgia lets amber lights stand in for the escort from 75′ to 100′. Utah only requires the escort at night until 120′1″. Arizona has no fixed length escort; over 120′ (its Class C permit zone) a law-enforcement escort may be required case-by-case during permit review. And Idaho, Montana, and Oklahoma set no overall length limit on the Interstate, so length alone never triggers an escort there, though all three require one on non-interstate roads.

See each state's first escort length in the map or table below. Use the calculator to check the exact escort count and position, and how length stacks with width and height on your route.

Why This Matters

Height, width, and length are three of the six dimensions our calculator checks for every state on your route. Weight and overhangs have their own state-by-state thresholds too, and each one can independently trigger permits, escorts, and travel restrictions.