North Dakota OS/OD Overview
Permit Required
Yes – any load exceeding legal size or weight must have a permit from the North Dakota Department of Transportation (NDDOT), with escort and movement rules enforced by the North Dakota Highway Patrol (NDHP). Single-trip and other oversize/overweight permits are issued through the NDDOT/NDHP motor carrier permit system.
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 75' (combo); 53' trailer allowed
- Weight: 80,000 lbs GVW (standard axle limits apply)
Anything over a legal dimension or weight requires an oversize/overweight permit before the move. Superloads beyond routine permit limits require engineering review, route survey, and possible bridge analysis.
Travel Hours
- Standard: Loads over 16' wide travel sunrise to sunset only; loads 12' or narrower (or overweight-only) may travel any time.
- Holidays: Loads over 16' wide are restricted from noon to sunrise on major state holidays.
- Night travel: Verify lighting and route conditions on the issued permit.
Escort Requirements
| Dimension | Escort Requirement |
|---|---|
| Width 14'6"–16' | 1 pilot car on 2-lane roads (amber lights may substitute below 16') |
| Width > 16' | Front + rear pilot cars on 2-lane highways; rear pilot car on 4-lane divided roads |
| Width > 18' | NDHP (state police) escort required |
| Height > 18' | Front pilot car with height pole required |
| Length > 120' | Rear pilot car required |
Detailed Information
POLICE ESCORT: An NDHP escort is required for widths over 18' (§37-09-04-01), and advance scheduling is required.
HEIGHT POLE: A front pilot car with a height pole is required when the load exceeds 18' in height.
PILOT CARS BY WIDTH: For widths over 16', front and rear civilian pilot cars are required on 2-lane highways, and a rear civilian pilot car is required on 4-lane divided roads. For widths of 14'6" to 16', one pilot car is required on 2-lane roads, and amber lights may substitute below 16'.
PILOT CARS BY LENGTH: A rear civilian pilot car is required for combinations over 120' overall length.
RESTRICTED TRAVEL: Sunrise-to-sunset travel only applies when width exceeds 16'; loads 12' or narrower or overweight-only may travel any time. Loads over 16' wide are also restricted from noon to sunrise on major state holidays.
Additional Notes
- "Oversize Load" signs, red/orange flags, and amber warning lights are required on the load and escort vehicles per NDDOT/NDHP permit conditions.
- Amber warning lights may substitute for a pilot car on widths below 16' in the 14'6" to 16' range on 2-lane roads.
- Permit conditions issued by NDDOT and the North Dakota Highway Patrol govern the specific move and may impose requirements beyond these general thresholds.
Source: North Dakota Highway Patrol — Motor Carrier Permits. Informational only — always verify against the live permit office before any move; permit conditions control.
