SDCL § 32-18-14: Capability of parking brake--Parking brake assisted by service brake.

The parking brakes shall be capable of being applied in conformance with the requirements of § 32-18-13 by the driver's muscular effort or by spring action or by equivalent means. Their operation may be assisted by the service brakes or other source of power provided that failure of the service brake actuation system or other power assisting mechanism will not prevent the parking brakes from being applied in conformance with the requirements of § 32-18-13.