South Dakota

South Dakota interstate GVW limit: 80,000 lbs. State highways allow up to 129,000 lbs with proper axle configuration. Per-axle limits: Single axle 20,000 lbs, Tandem axle 34,000 lbs, Tridem axle 42,000 lbs. Federal bridge formula on interstates; South Dakota allows higher GVW on state highways with additional axles. Enforcement tolerance: No general tolerance during spring restrictions.

Height: 14 ft. Width: 8 ft 6 in. Trailer length: 53 ft (semitrailer). Overall combination length: 100 ft combination (on designated routes).

Oversize/overweight permits through SDDOT online portal; farm machinery dealer and feed hauler exemptions Fees: Single-trip: $20; Annual: $100. North Dakota oversize/overweight permits are honored under reciprocal agreements. Verify specific terms before travel. Apply online: https://dot.sd.gov/transportation/highways/motor-carrier-services/permits Enforcement: SDHP and SDDOT enforcement; weigh stations; fines per pound overweight.

Agricultural: Agricultural vehicles exempt; farm machinery dealers, feed haulers, and mobile home movers have special provisions.

Spring weight restrictions on posted roads; reduced weights during thaw 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 South Dakota DOT page at https://dot.sd.gov/transportation/highways/motor-carrier-services/. Contact the South Dakota Department of Transportation for specific routing questions.