New Hampshire

New Hampshire interstate GVW limit: 80,000 lbs. Per-axle limits: Single axle 22,400 lbs, Tandem axle 36,000 lbs, Tridem axle 42,000 lbs. Federal bridge formula applies; many covered bridges have significantly lower limits. Enforcement tolerance: No tolerance during spring restrictions.

Height: 13 ft 6 in. Width: 8 ft 6 in. Trailer length: 53 ft (semitrailer). Overall combination length: No overall limit for tractor-semitrailer.

Oversize/overweight permits through NHDOT Bureau of Highway Maintenance Fees: Single-trip: $20; Annual: $100. Tennessee oversize permits are not directly honored in New Hampshire. You will need to obtain a New Hampshire-specific permit for oversize/overweight loads. Apply online: https://www.nh.gov/dot/org/operations/highwaymaintenance/oversizeoverweight/ Enforcement: State Police and NHDOT enforcement; fines per pound overweight.

Agricultural: Agricultural vehicles exempt on local roads. Timber/Forestry: Timber trucks allowed higher weights on designated logging roads.

Spring weight restrictions (posted roads) from March through May; strict enforcement during mud season. Check with the state DOT for current postings and dates before planning your route.

For the most current weight and size regulations, permit applications, and seasonal restriction updates, visit the official New Hampshire DOT page at https://www.nh.gov/dot/org/operations/highwaymaintenance/oversizeoverweight/. Contact the New Hampshire Department of Transportation for specific routing questions.