S.D. Codified Laws § 31-29-80.1
The transportation commission shall promulgate rules, pursuant to chapter 1-26, to provide for a directional sign program to provide directional information on the right-of-way on the interstate and primary highway system for any business establishment, including any attraction, offering goods and services in the interest of the traveling public. The rules shall be developed in conformance with the manual on uniform traffic control devices and shall address permit application criteria; sign message and types of qualifying services; hours and periods of operation; qualifying distance to services; business sign priority; sign and panel locations and spacing; number and priority of signs per panel; sign and panel composition, size and color requirements; legend requirements; exit ramp sign size, spacing and message content; covering or removal of business signs; and erection and maintenance of signs and panels.
SDCL 31-29-80.1