Legal truck size limits without a permit

What counts toward the width

Rear view mirrors, turn signal lamps, handholds for cab entry and exit, splash and spray suppressant devices and load-induced tire bulge are excluded from measured width, along with non-property-carrying devices that extend no more than 3 inches beyond each side of the vehicle.23 CFR 658.16 - Exclusions from length and width determinations.Recorded access date: Nov 1, 2026 Non-property-carrying devices stay excluded only up to 3 inches per side. Nothing in the list excludes the load itself, so cargo that sticks out past the trailer is part of the measured width.

That means measuring the loaded truck, not the trailer deck. A machine on a flatbed that sits inside the deck edges is legal width; the same machine with a bucket or track hanging over the side is an oversize load the moment it passes the limit.

Legal width, height and trailer length in every state

Each figure is the largest size a truck and load can be under that state’s general rule without an oversize permit. Width is 8 ft 6 in almost everywhere; the exception is Hawaii (9 ft), so check that state's own rule before relying on the federal figure off the National Network. In 20 jurisdictions, height runs higher than 13 ft 6 in: Alaska, Arkansas, California, Colorado, Hawaii, Idaho, Kansas, Montana, Nebraska, Nevada, New Mexico, North Carolina, North Dakota, Oklahoma, Oregon, South Dakota, Texas, Utah, Washington and Wyoming.

Length rules carry conditions the single number cannot show, such as kingpin-to-axle distances and limits for specific combinations. The state-by-state notes print each state’s exact wording with its source.

Over the limit: what the permit step looks like

A load past any legal number needs an oversize or overweight permit before it moves. Federal rules have each state issue its own oversize permits, so each state on the route decides whether to permit the move on its own roads.Federal Size Regulations for Commercial Motor Vehicles (FHWA-HOP-04-022)Recorded access date: Nov 1, 2026 A state that lets a vehicle wider than 102 inches, other than special mobile equipment, run on the National Network must issue it a special overwidth permit.Federal Size Regulations for Commercial Motor Vehicles (FHWA-HOP-04-022)Recorded access date: Nov 1, 2026 States may issue special permits that set aside the axle, gross and bridge formula limits for loads or vehicles that cannot be divided.23 CFR 658.17 - Weight.Recorded access date: Nov 1, 2026

Some states can join regional permit agreements. Maine law, for one, lets the Commissioner of Transportation enter regional overdimensional truck permit agreements to establish consolidated multistate overdimensional and overweight permits. A regional permit covers only the states that take part, so confirm with the permit office of the first state on the route whether one covers the whole trip.Maine Revised Statutes Title 29-A, section 2384: Regional overdimensional truck permitsRecorded access date: Nov 1, 2026

Base fees, annual permit options, escort triggers and the issuing office for each state are in oversize permit costs by state. To price a route across several states, run the oversize permit cost estimator. Permits sit on top of the registrations the truck already carries, so heavy-haul carriers also keep IRP apportioned plates and the rest of the trucking permits by state current, and they plan stops around weigh stations, where officers check size and weight.