North Dakota Oversize Load Permits, Regulations & Axle Rules

North Dakota's window for permitted oversize loads runs 30 minutes before sunrise to 30 minutes after sunset, seven days a week, but only if the load sits in the right band. The rules carve out three. Loads that are overweight only, or 12 feet wide or less and 120 feet long or less, may run any day or night with proper lighting. Loads that are over-height or over-length only (without being overwide) move any day inside the daylight window. The tightest band, no nights plus weekend and holiday limits, applies to loads wider than 16 feet.

For loads over 16 feet wide, Saturday travel cuts off at noon and Sunday is out entirely. Six holidays are blocked, and the blackout runs wider than the calendar day: movements over 16 feet wide stop from noon the day before the holiday until sunrise the day after. The six are New Year's Day, Memorial Day, Independence Day, Labor Day, Thanksgiving, and Christmas.

Loads at or under 16 feet wide are not affected by any of that. They travel as stipulated on every holiday and weekend. Martin Luther King Day, Presidents Day, Good Friday, and Veterans Day carry no travel restrictions for any permitted load.

Several stops apply regardless of width. No permitted movement when inclement weather prevails, highways are slippery, or visibility is half a mile or less. Overweight permits on bituminous pavement go dark when the air temperature hits 90 degrees F. Shoulder travel is prohibited on all permits. Convoys of two or more vehicles keep at least 1,000 feet between permitted vehicles. North Dakota imposes no rush-hour or metro curfews, and there is no continuous 24-hour movement of oversize loads.

North Dakota's deepest carve-outs run through agriculture and construction, with a handful of length exemptions that let certain loads run uncapped.

Implements of husbandry get substantial relief when moved by resident farmers, ranchers, dealers, manufacturers, or governmental entities. Width restrictions don't apply on non-interstate highways during daytime, or nighttime if the vehicle is properly lit. Height up to 15'6" is allowed when the trip is 60 miles or less, runs sunrise to sunset, and stays off the interstate. A single axle hauling an implement in tow by a North Dakota implement manufacturer may go up to 30,000 lbs, subject to a 550 lbs-per-inch tire limit. Commercial operators moving haystack equipment, overwidth fertilizer spreaders, ag chemical applicators, hay grinders, grain cleaners, and forage harvesters can run under seasonal permits rather than single-trip permits.

Hay in the stack, when moved by a non-commercial mover along the extreme right edge of the roadway, sunrise to sunset, needs no permit for width overages.

Construction and building equipment up to 10 feet wide, moved by contractors or resident carriers, is exempt from width limits without a permit. This includes housemover vehicles, rig-up trucks, and gin trucks. Building moving equipment is also exempt from all length limitations.

Truck-mounted haystack moving equipment is exempt from length limits up to 56 feet overall. Structural material of telephone, power, and telegraph companies is exempt from all length limits without cap.

Self-propelled earthmoving equipment (scrapers, rubber-tired dozers, loaders) runs under its own ruleset. Maximum permitted axle weight is 52,000 lbs (district engineers may authorize more, but only for one-way trips of 5 miles or less). Tires must be deflated to 30 psi when cold before driving on bituminous pavement, speed is capped at 20 mph, and a rear pilot car is required. After every two hours of travel, the equipment stops and cools tires for 30 minutes. During spring road restriction periods, earthmoving equipment exceeding 650 lbs per inch of tire width or 30,000 lbs on a single axle may not travel on bituminous pavement at all. North Dakota's alternate option, mounting the front axle on a jump trailer while the rear axle trails on the ground, is available up to 150,000 lbs GVW, subject to the same tire pressure and pilot-car rules.

North Dakota also runs a 129,000 lb Primary Network Permit covering designated primary state highways above the standard 105,500 lb state highway limit, available as a single trip, 30-day, or annual permit.

Harvest and spring weight provisions matter. A seasonal 10% weight exemption permit is available for harvest and wintertime periods. Overweight permits are not issued at all during spring road restrictions, except under the Road Restriction Permit Policy or a declared emergency, and all overweight movements on state highways (excluding the interstate) are subject to ton mile fees.

North Dakota uses the word Superload in its permit policy, defining it as "a vehicle or load movement that is excessive in size and weight." The definition is qualitative, not numeric: the policy sets no specific width, height, or length figure that tips a load into superload status. Instead the state uses escalating weight tiers, each adding requirements.

Over 150,000 lbs GVW: tandem axle max drops to 40,000 lbs and single axle to 22,000 lbs; graduated permit fees apply ($30 to $70 based on GVW tier).

150,001 to 175,000 lbs: if the requested route can't be approved, the load must be reduced (rippers off dozers, scrapers limited to one piece, no piggybacking). District engineer approval required unless the route is on a pre-approved GVW map.

Over 175,000 lbs: blades and rippers come off dozers entirely, scrapers split and hauled separately, counterweights off cranes. District and bridge engineer approval required.

Over 200,000 lbs: subject to the Heavy Load Permit Policy (Policy 9-6 Annex E), with ton mile fees. Crossing a state highway at these weights also requires a DOT district engineer sign-off plus a traffic control plan.

Over 250,000 lbs GVW: a track width diagram (load diagram) must be filed with the application, along with any non-standard trailer or narrow-track configuration.

Because the superload definition is weight-driven rather than tied to oversize dimensions, there's no overwidth or overheight superload tier per se. Extreme oversize loads that don't cross the heavy weight tiers run through the standard permit process, pilot car requirements, and the clearance obligations in the Route Survey section. The permit office, NDHP Motor Carrier Operations in Bismarck, is the single point of contact for all single-trip permits, reachable online through E-Permits or by phone at 701-328-2621.

North Dakota places responsibility for vertical clearances entirely on the carrier, not the state. The policy states plainly: "ALL VERTICAL CLEARANCES SHALL BE THE RESPONSIBILITY OF THE PERMITTEE." That framing is the foundation of how route checking works here.

For overheight loads, the carrier self-survey obligation kicks in progressively. Any load exceeding 18 feet in height must obtain written authority from each utility company before traveling under overhead wires. Communication cables can run as low as 15'6", signal lights as low as 16 feet, flashing signal lights as low as 17 feet. Load heights at 16 feet or higher on US Highway 85 between Grassy Butte and Williston require contacting the Western Area Power Administration (WAPA) before travel. The DOT's bridge vertical clearance list is consulted when issuing all overheight permits and may trigger route restrictions or diversions around structures with insufficient clearance.

For overweight loads, the route review is engineer-driven rather than carrier-performed. Over 150,000 lbs: district engineer approval unless the route is on the pre-approved GVW map (Policy 9-6 Annex D). Over 175,000 lbs: both the district engineer and the bridge engineer must approve the route; if they can't approve the requested route, the load must be reduced or the move doesn't happen. Over 200,000 lbs: the Heavy Load Permit Policy applies, and any state highway crossing requires district engineer approval with a full traffic control plan submitted in advance.

Routing for all overweight movements is also constrained by four published maps: the Permit Bridge Load Limitations Map, the Approved GVW Map, the Weight Limitations Map, and the Load Restriction Map (real-time at travel.dot.nd.gov). These are conditions of the permit, not optional checks. There's no published lead-time requirement for standard permits (E-Permits handles loads that don't require engineer review automatically), but movements into the 175,000+ lb tiers need engineer coordination started well before the move date.

The North Dakota Highway Patrol (NDHP) is the law enforcement agency for OS/OW escort, and its involvement is discretionary, not triggered at a fixed threshold. Once a load exceeds 18 feet in overall width, the movement is "subject to Highway Patrol escort if deemed necessary by the regional commander(s)." That call is case by case. There's no width or weight at which a trooper escort becomes automatic.

When the NDHP is involved, it's in addition to any private pilot car escorts already required, not a replacement. The moving company contacts the regional commander in every region the load will travel through, after the permit is in hand, not before. Because the regional commander decides whether an escort is warranted, there's no guarantee either way. Load characteristics, route conditions, and time of movement all factor in. When an NDHP trooper escorts a move, the rate is $50 per hour plus $0.50 per mile per trooper.

The private pilot car (North Dakota's standard term for an escort vehicle) handles most oversize movements. A pilot car must be a passenger vehicle or two-axle single-unit truck, carry a minimum 12" x 60" "OVERSIZE LOAD" sign on its highest point with black lettering on yellow at least 8 inches tall, display flashing amber lights on both ends of the sign (or a single centrally mounted revolving amber light), and maintain radio contact with the escorted vehicle at all times. Pilot cars must hold a distance of 300 to 700 feet from the load, a tighter range than most states specify. On two-lane highways, loads over 16 feet wide require both a front and rear pilot car; on four-lane divided highways, only a rear pilot car is required at that width. Loads between 14'6" and 16 feet wide on two-lane highways may substitute rotating or flashing amber lights visible 500 feet front and rear in place of a pilot car.