Key South Dakota Trailer Laws And Regulations

Trailers are a great way to transport heavy loads without putting too much stress on your vehicle. However, there are laws and regulations governing their use, which you need to be aware of before you hit the open road. In this article, we will discuss some of the key South Dakota trailer laws and regulations that you need to be aware of.

Do South Dakota Trailers Need To Be Licensed?

If you own a trailer that weighs less than 6,000 pounds and uses it with an automobile, pickup truck, or van, you must purchase a regular annual trailer plate. There are no weight restrictions on trailers that are licensed in this manner. Vehicles that are licensed for the gross weight (commercial and non-commercial) may tow any regularly licensed trailer as long as the weight of the trailer plus its load is included in the towing vehicle's gross weight license.

If a trailer being pulled by a truck or commercial vehicle is registered under the declared gross weight schedule, then it's allowed to have a trailer identification plate displayed instead of the standard license identification.

The $10 fee is a one-time charge, provided the trailer is owned by the applicant. No license plate can be displayed on a recreational vehicle. If the trailer's license Plate is lost, the licensee must fill out a duplicate affidavit and submit another $10 fee to their county treasurer.

South Dakota Trailer Laws & Regulations


For every trailer you wish to tow on a public highway at a speed exceeding 20 mph, in addition to the regular hitch or coupling device, you must also connect it to the tow vehicle with either chain, cables, or another equivalent safety measure. The only exception to this rule is if your semitrailer has a connecting device that consists of both a 5th wheel and kingpin assembly which abides by Interstate Commerce Commission standards.


The maximum length for a trailer (including bumpers and excluding all safety and energy conservation devices) is 75 feet, with the overall length not exceeding 75 feet when combined with a second trailer that does not exceed 24 feet in length. The width of trailers must be 102 inches (excluding all safety and energy conservation devices), while the height limit is set at 14 feet.


All trailers and semitrailers must have a braking system that can be controlled with one device.

Trailers that weigh less than 3,000lbs and semitrailers that weigh no more than 7,000lbs do not have to be equipped with brakes on all wheels if: (1) the weight of the trailer's wheels does not exceed 40% of the gross weight of the vehicle pulling it when connected; and (2) The vehicle-trailer combination can meet all other performance requirements.

Hitch and Signals

You can mount the ball hitch on the bumper or frame; a safety chain is required in either case.


All motor vehicles that are tow other vehicles must have a mirror installed in a way where the driver can see 200 feet behind them.


Older trailers and semitrailers (manufactured before July 1, 1973) are only allowed to have one red tail lamp on the left side. The light must be visible from 500 feet away.

Speed Limits

The speed limit is 65 mph on all secondary highways unless indicated otherwise by a posted sign. The speed limit is 75 mph on interstate highways, Again, unless there is a posted sign saying differently.

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