South Dakota Trailer Laws & Trailer Regulations

South Dakota's laws and regulations for trailers are listed below:


South Dakota Trailer Brake Laws

Every trailer and semitrailer must be equipped with a braking system that is arranged so that 1 control device can be used to operate all of the service brakes.

Trailers, semitrailers, or pole trailers of a maximum gross weight of less than 3,000 lbs. and trailer and semitrailers not exceeding 7,000 lbs. manufactured before July 1, 1974 do not have to be equipped with brake action on all wheels provided that: the total weight on and including the wheels of the trailer or trailers does not exceed 40% of the gross weight of the towing vehicle when connected to the trailer or trailers; and (2) the combination of vehicles consisting of the towing vehicle and its total towed load is capable of complying with all performance requirements.



South Dakota Trailer Dimension Laws

Total length: 75 feet (Includes bumpers; excludes safety and energy conservation devices, including mirrors, turn signals, lamps, and handholds. Overall length cannot exceed 75 feet with second trailer not exceeding 24 feet); trailer length: 53 feet; trailer width: 102 inches (Excludes safety and energy conservation devices.); height: 14 feet. 



South Dakota Trailer Hitch and Signal Laws

Either ball hitch mounted on bumper or secured to frame is permitted; safety chain is required. 



South Dakota Trailer Lighting Laws

Trailers and semitrailers manufactured before July 1, 1973 can have 1 red tail-lamp mounted on the left-hand side which emits a light from a distance of 500 feet.



South Dakota Trailer Mirror Laws

Every motor vehicle when towing another vehicle must be equipped with a mirror located so that the driver has a rear view for a distance of at least 200 feet to the rear of the vehicle. 



South Dakota Trailer Speed Limit Laws

65 mph on secondary highways except where posted. 75 mph on interstate except where posted. 



South Dakota Trailer Towing Laws

In addition to the regular trailer hitch or coupling device, every trailer that is towed on the public highways at a speed of more than 20 mph must be coupled to the towing vehicle with a safety chain, chains, cables, or an equivalent device. This requirement does not apply to a semitrailer having a connecting device composed of a 5th wheel and kingpin assembly that meets the requirements of the Interstate Commerce Commission.  






The United States Trailer Laws and Regulations by State by is not an inclusive list of laws, regulations and it should be used by reference only and not used for any other purpose. is not liable for incorrect or incomplete information. To report an error, incomplete or incorrect information, please send an email to