Check Your Truck’s Size & Weight Configurations

Carriers operating in South Dakota must operate within the maximum length, height, width and axle limitations and comply with South Dakota bridge and weight laws. Information can be obtained by calling the Motor Carriers Services division of the South Dakota Highway Patrol at 605.224.7364.

Legal Weight Calculator

Sign into out permitting system to use our legal weight calculator. You’ll need your tire sizes for single tire axles and your axle spacings. You can print off the calculations and retain for future reference!

Below is a brief synopsis of size & weight regulations. For complete information and illustrations, please refer to Chapter 5: Size and Weight Regulations of the SD Commercial and Agricultural Vehicle Handbook.

Vehicle Size Regulations

Height Limitations

The maximum height for any vehicle, including load, is 14 feet.
1. A vehicle with a load of baled hay is permissible up to 15 feet
2. Farm Machinery and Fire Equipment: No Height Limit

Width Limitations

The maximum width of any vehicle is 102 inches (8 feet 6 inches).Exception:
1. Farm Machinery Operated by a Farmer: No Width Limitation during daylight hours except on the interstate system

Length Limitations

Length limitations are illustrated in Table 7 of the South Dakota Commercial and Agricultural Vehicle Handbook. Unless specifically addressed, the length limits shown only apply to the vehicle, and not to the load carried on it. They are exclusive of the load overhang, retractable extensions used to support loads, and safety or energy conservation devices such as mirrors, turn signal lamps, hand holds, flexible fender extensions, and mud flaps. Retractable extensions must be retracted if not being used to support overhanging loads.


Loads or retractable extensions on any vehicle may not extend more than four feet beyond the rear bumper, bed, or body, or more than three feet beyond the front bumper, bed or body of the vehicle carrying the load.

Vehicle Weight Regulations

Axle Group Limitations

The maximum allowable weight for all individual axles and axle groups is limited by statute:

Tire Limitations

The weight supported on a tire may not exceed 600 pounds per inch width of tire, if that tire is on:
1. A steering axle
2. An axle equipped with dual tires; or
3. A trailer towed by a vehicle with a Gross Vehicle Weight Rating of 11,000 pounds or less.
The weight supported by tires mounted on other axles may not exceed 500 pounds per inch width of tire.

Posted Structures

Spring Load Restrictions

Here you will find information on spring load limits

Load Postings for Structures on State Routes

Here you will find load postings for structures on state routes across South Dakota

State-Owned Structures Posted for Emergency Vehicles

Here you will find a list of posted structures with exceptions for emergency vehicles