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Oversize Load Permits

Wide, tall or long equipment often needs advance permission to travel on public roads. The rules differ by state, so the safest habit is to ask before you load, not after you are stopped.

What counts as an oversize load?

An oversize load is one that is wider, taller, longer or heavier than the standard limits for that road. Combines with large headers, planters with folding toolbars, sprayers, grain carts and tall bale stackers are common examples on farm roads. Whether your particular rig crosses the line depends on measurements and on the rules of each state you travel through.

Do not rely on what a neighbor did last year. Laws are rewritten, and exemptions for farm equipment can be narrow, seasonal or limited to certain distances or hours. Measure your load fully loaded and configured the way it will actually travel.

How do you find the rules that apply to you?

Start with the state department of transportation, which usually runs the permit office or has a permit desk or website. Many states also have a motor carrier or oversize and overweight permit unit. Ask whether your equipment is treated as an implement of husbandry, a commercial load, or something in between, and ask for the answer in writing if you can.

If you cross a state line, you need to check each state separately. Counties, cities and townships may also control certain roads or bridges, so ask about local routes, not only highways. This site does not list thresholds or fees because they change and differ everywhere.

• State department of transportation permit office
• State highway patrol or state police commercial vehicle unit
• County road department or township office for local roads
• Your equipment dealer, who often hauls wide loads regularly

What information will you probably need ready?

Permit offices typically ask for the dimensions and weight of the load, the type of vehicle and trailer carrying it, the planned route, and the dates of travel. Having these written down before you call saves time and prevents mistakes that could void a permit.

Take photographs and measurements of the machine in transport position. Check the operator's manual for transport instructions, since many machines fold, collapse or detach parts to reduce width. Using the manufacturer's transport mode is often the simplest way to reduce what you need to permit.

What conditions might a permit place on your trip?

Permits can carry conditions. These may include travel only in daylight, restrictions on weekends or holidays, avoidance of certain bridges or urban areas, required warning signs or flags, lighting, and in some cases escort vehicles. The conditions come from the permitting authority, not from this article, so read every line.

Keep the permit in the cab and follow it exactly. Driving off the permitted route to save time can void the permit and may leave you liable if something goes wrong. If weather or a road closure forces a change, stop somewhere safe and contact the permit office.

How do you plan the physical route?

Drive or review the route before you haul. Look for low wires, overpasses, narrow bridges, tight turns, mailboxes, sign posts, parked vehicles and railroad crossings. Overhead lines are a serious hazard for tall equipment, and your local utility can help with questions about known low spots.

Think about timing too. Early morning or off-peak travel often means fewer vehicles to pass. Tell family or employees your route and expected arrival, and carry a way to call for help.

What are the common mistakes?

The most common problems are assuming an exemption applies, measuring the empty machine rather than the loaded configuration, forgetting that tires, mirrors and lights add width, and leaving too little time to get a permit before harvest or planting pressure builds.

Plan ahead before the busy season. Ask your permit office how long processing usually takes. Build the permit step into your calendar the way you would schedule a service visit, and you will avoid rushed decisions on the road.

Who should know about your plans?

Tell the people who will be on the road with you. Employees, family members and neighbors who help should know the dimensions of the load, the permitted route and the time window. Share the plan with anyone who may be driving the escort or following behind.

Also consider telling your local sheriff or township office when you plan a long or unusual move. They cannot replace a permit, but they often know about road work, closures and events that could stop a wide load on short notice.

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.