South Dakota Pilot Car Services

PERMITS
In South Dakota, oversize permits are valid for three days and must be obtained before entering the state.

OPERATING HOURS
Travel is allowed from 30 minutes before sunrise to 30 minutes after sunset, including weekends. Loads up to 10 feet wide, 14 feet 6 inches high, and 110 feet in overall length may operate continuously on Interstate highways and within a 2-mile radius of Interstate interchanges on state routes. Overweight-only loads are permitted to travel 24/7.

LEGAL DIMENSIONS

Length:

• Semi-trailer: 53 feet
• Overall vehicle length: No specific limit
• Overhang: 3 feet front, 4 feet rear
  Note: Items such as poles, pipes, beams, and utility structures are not exempt from length or overhang restrictions.

Width: 8 feet 6 inches
Height: 14 feet
Gross Weight: 80,000 pounds

• Single axle: 20,000 pounds
• Tandem: 34,000 pounds
• Tridem: 42,000 pounds
• Steer axle: Maximum 600 pounds per inch of tire width

DIVISIBLE LOADS OVER 80,000 POUNDS
Divisible loads exceeding 80,000 pounds are allowed on state highways without a permit, provided axle and group weights are legal and registration covers the total gross weight. Interstate routes require an "Interstate Permit."

ROUTINE PERMIT LIMITS
Limits vary based on the route. The permit office determines specifics.

Typical Weight Limits:

• Single axle: 24,000 pounds
• Tandem: 46,000 pounds*
• Tridem: 60,000 pounds*
• Quad: 68,000 pounds*
• Steer axle: 600 pounds per inch (13,200 for 11-inch tires)

*Must be registered for at least the permitted weight or pay extra on a trip permit. Routes may allow higher limits. All axles must be deployed for overweight loads. Tractors must be registered for the weight hauled or will require an extra trip fee.

ESCORT REQUIREMENTS

Length:

• Over 130 feet: 1 escort required

Width:

• Interstate highways: Over 16 feet requires 1 escort
• Most state highways: Over 20 feet requires 1 escort
• Additional escorts may be required if the load extends into adjacent lanes or if vehicles must use the shoulder to pass
• In the Black Hills region (except US16 from Rapid City to Keystone and US18): Over 10 feet requires 1 escort

Height:

• Generally, no escort required

SEASONAL LOAD (WEIGHT) RESTRICTIONS
Spring thaw restrictions may begin any time after February 15. Contact the permit office for current updates.

SIGNS, FLAGS & LIGHTING
All loads exceeding legal dimensions must have flags on all corners if wider than 8 feet 6 inches or if projections extend past the front or rear of the vehicle.

• For projections over 3 feet front or 4 feet rear: Flags are required
• If a projection is under 2 feet wide: 1 flag required
• Over 2 feet wide: 2 flags required
• “Oversize Load” or “Oversized Load” signs are required on the front and rear of vehicles exceeding 12 feet in width, 95 feet in length, or operating at night
• Signs must be reflective for night use and removed or covered when not in use
• Load projections must be equipped with amber and red lights, as well as reflectors, when traveling at night. Night lighting specifications are detailed on the permit.