New Hampshire

Permits are valid for 5 days. Driver must have permit prior to entering the state. Permits are not valid if oversize pre-trip is not completed.

Travel is allowed one-half hour before sunrise to one-half hour after sunset, Monday through Friday. No weekend or holiday travel for over dimensional loads. Overweight only are permitted continuous travel.

No travel allowed on major holidays and holiday weekends.

Width: 8’6″
Height: 13’6″
Length: 53′ semi-trailer on Interstate and designated highways (41′ Kingpin to center of rear tandem);
48′ semi-trailer on all other roads. Length limitations do not apply to vehicles transporting poles, pipes, logs, timbers, steel beams (not for stretch trailers)
Weight: 80,000 Gross Single – 20,000 designated highways* (22,400 other roads)
Tandem – 34,000 designated highways* (36,000 other roads) Tridem – Same as tandem
* When GVW isn’t over 73,280 pounds, 22,440 pounds legal on a single axle, and 36,000 on a tandem.

Width: 16′
Height: 16′
Length: 110′
Weight: Single – 25,000 Tandem – 50,000 Tridem – 70,000
Loads exceeding these dimensions are treated as super loads.
A bridge review is required when: any single axle exceeds 27,500 pounds, any axle of a tandem exceeds 25,000 pounds, any axle of a tridem exceeds 22,500 pounds, any axle of a quad exceeds 20,000 pounds, any 5-axle combination exceeds 100,000 pounds, any 6-axle combination exceeds 120,000 pounds, any 7-axle combination exceeds 130,000 pounds, any combination of 8 or more axles exceeds 149,999 pounds.

Width: At 12′ – 1 escort; over 15’1” – 1 State Police escort (need 48 hour notice).
State may require a second escort for some routes.
Height: Route survey is required for over 13’6″, escort not usually required for height
Overhang: Over 15′ – 1 escort; 2 escorts are required if overhang exceeds 15′ and width is over 12′.
Length: At 80′ – 1 escort; over 100′ – 1 escort and 1 State Police.

“Oversize Load” sign is required. Flags (at least 18″ square) are required on all corners and extremities of the load when over width, and over length. The hauling vehicle shall have an operating, top mount, flashing or strobe amber light visible for 1000 feet in all directions.