S.D. Codified Laws § 32-17-42
Any motor vehicle authorized by the Department of Transportation, a tow truck or wrecker as defined in § 32-17-10, or a vehicle operated by a member of an organized fire department or organized search and rescue unit or by a person who is an ambulance driver, attendant, or emergency medical technician affiliated with a licensed ambulance service may be equipped with blue lights. This provision does not relieve the driver of the vehicle from the duty to drive with due regard for the safety of all persons using the street nor does it protect the driver from the consequence of a reckless disregard of the safety of others.
No person may use a blue light unless the person is authorized by this chapter and is operating a Department of Transportation vehicle or a county highway vehicle in performance of winter highway maintenance duties, or actually en route to the scene of a fire or other emergency requiring the person's services and the person has been authorized in writing to so use a blue light. Authorization for use of a blue light in accordance with this chapter may be given by the Department of Transportation, highway patrol, county highway superintendent, chief of a fire department, coordinator of a search and rescue unit, or operator or ambulance service director of an ambulance service only to members of the department or service who are in good standing.
The use of a blue light in violation of this section is a Class 2 misdemeanor.
SDCL 32-17-42