S.D. Codified Laws § 32-28-8.2
Procedure when traffic lights malfunctioning
If a traffic control signal is out of operation or is not functioning properly, the vehicle traffic facing a:
(1) Green signal may proceed with caution as indicated in § 32-28-2 ;
(2) Yellow signal may proceed with caution as indicated in § 32-28-3 ; and
(3) Red or completely unlighted signal stop shall stop in the same manner as if the vehicle is at a stop sign.
Source: SL 2000, ch 160, § 1.