Oversize Load Permit Requirements
by State (2026)

Federal law sets the baseline limits for vehicles operating on Interstate highways. Any combination vehicle that exceeds these dimensions or weight limits requires an oversize or overweight permit from each state it travels through. These are the numbers every shipper needs to know before moving heavy freight.

The Bridge Formula (Formula B) further limits weight based on axle spacing. Even if your gross weight is under 80,000 lbs, the Bridge Formula can require you to spread axles further apart to stay legal. A freight broker handles this calculation as part of load planning.

Important: These federal limits apply to Interstate highways. State highways, US routes, and county roads may have lower limits. A load that's legal on an Interstate may need a permit on a connecting state road — especially for the first and last few miles of the move.

While the federal baseline is consistent, states have significant latitude in how they administer oversize and overweight permits. Here are the main variables that differ across state lines:

Height limits. Most states use 13'6" as the threshold above which a height permit is required. A handful allow 14'0" without a permit on designated routes (Texas and California on certain highways are common examples). Height permits do not guarantee clearance — the actual route must be surveyed for bridges and overhead utilities.

Width limits for secondary roads. While Interstate and primary highway limits are uniformly 8'6", many states reduce this to 8'0" on secondary or county roads. A load that's permit-free on the Interstate may need a width permit to reach a job site on a rural road.

Annual vs. single-trip permits. Many states offer annual or blanket oversize permits for routine haulers — for example, a carrier that regularly moves equipment up to 10' wide within a state can often buy a single annual permit rather than filing for each trip. Single-trip permits are always available but cost more per move for repeat freight.

Travel windows. States set their own rules for when oversize loads may move. Night moves are restricted or prohibited in most states. Weekend restrictions vary significantly — some states allow Saturday daylight moves but not Sunday; others restrict movement on all holidays. Some states limit movement to specific hours, such as one hour after sunrise to one hour before sunset.

Permit processing time. Standard oversize permits often process within one business day in states with online systems (Texas, Florida, Indiana). States with manual review can take 3–5 business days. Superload permits (over roughly 150,000 lbs or 16'+ wide) require engineering review and can take 2–6 weeks per state regardless of the processing system.

Pilot car requirements. Escort vehicle requirements — type, quantity, and at what load dimensions they're triggered — vary significantly. See the pilot car section below.

Pilot cars — also called escort vehicles or flag cars — travel ahead of or behind an oversize load to warn traffic and assist with clearances. Requirements vary by state and by load dimension. The table below shows the general national thresholds; always verify state-specific rules on your permit.

Pilot car certification. Many states require pilot car drivers to be certified — meaning they've completed a state-approved training course and may carry proof of certification in the vehicle. Some states accept other states' certifications; others do not. Uncertified escort drivers can result in permit violations and fines even if the load itself is compliant.

Your permit will state the exact travel window allowed for your specific load, route, and state. Violating travel restrictions — even by minutes — can result in fines, impoundment, and permit revocation. Build schedule buffer into any multi-state move.

The table below shows the general permit trigger thresholds for each state. These are guidelines only — actual limits depend on the route, road type, and load configuration. Dimensions shown are the maximums legal without a permit on primary state highways and Interstates. Secondary road limits are often lower.

Getting permits for a multi-state heavy haul move involves more than filling out a form. Here's the sequence from load measurement to wheels rolling.

When a load exceeds standard oversize permit maximums — typically over 150,000 to 200,000 lbs gross, wider than 16 feet, or taller than 16 feet — it enters superload territory. Superloads are reviewed individually by each state's engineering department, and the process is fundamentally different from a standard oversize permit.

What makes superloads different:

Every state conducts an engineering review of the specific load, route, and bridge structures. States may require structural analysis reports from a licensed PE (Professional Engineer). Bridge stress calculations are reviewed for every bridge on the route. If a bridge can't support the load, the route must be modified or the load must be split.

Typical superload permit timeline: 2 to 6 weeks per state. Moves crossing 5 states can take 6–10 weeks to fully permit if states review in parallel, or longer if sequential. Some states will not issue a permit until they receive approval from adjacent states on the route.

Common superload cargo: power transformers (200,000–400,000+ lbs), nuclear reactor vessels, petroleum refinery columns and reactors, large industrial generators, offshore platform structures, and bridge segments.

Perpetual coordinates the full superload permit package — engineering documents, route surveys, state filings, police escort coordination, and utility clearances — across all state lines. Contact us at info@perpetual.llc well in advance of your target ship date for superload moves.