South Dakota Pilot Cars / Escort Vechicle Requirements

When escort vehicles are required:

Escort vehicles are required in front on two-lane highways or in the rear on divided highways. Vehicles over 16 feet wide traveling on the interstate highway system require an escort. Vehicles over 20 feet wide traveling on the state highway system require an escort. The permit-issuing authority may also require escort vehicles because of route limitations, traffic conditions, or unusual permit vehicle configuration conditions.

Except on U.S. Highway 16 from Rapid City to the Keystone Wye and on U.S. Highway 18, a vehicle that exceeds a width of 10 feet must be accompanied by a front escort when operating on state highways in the Black Hills area. The Black Hills area is that area south and west of Interstate Highway 90 from the Wyoming state line to Rapid City, west of State Trunk Highway 79 from Rapid City to the junction of State Trunk Highway 79 and U.S. Highway 18, west of U.S. Highway 18 from the junction of State Trunk Highway 79 and U.S. Highway 18 to Oelrichs, and west of U.S. Highway 385 from Oelrichs to the Nebraska state line. A local highway patrol trooper may waive the front escort requirement for a specified period of time on any section of state highway in the Black Hills area if the highway has adequate geometrics to provide for the safe operation of the vehicle.

Escort Vehicles - Minimum requirements

The following are the minimum requirements for escort vehicles except as otherwise provided for in this chapter:

• Escort vehicles must be licensed motor vehicles. Motorcycles may not serve as escort vehicles;
• Escort vehicles must display a revolving amber light or two two-way flashing amber lights. The lights must be at least four inches in diameter;
• Escort vehicles must have signs with wording such as "WIDE LOAD AHEAD" or "WIDE LONG LOAD" in letters at least 12 inches high. The sign "WIDE LONG LOAD" shall be mounted on the front of the leading escort vehicle and the sign "WIDE LOAD AHEAD" shall be mounted on the back of the trailing escort vehicle;
• Bright red or orange flags at least 12 inches square shall be mounted on brackets or standards on each side of the sign; and
• Signs shall be covered or removed when not actually escorting a load.

Source of information: https://sdtruckinfo.sd.gov/laws_rules.aspx