32-25-5. Minimum speeds on interstate highways--Violation as misdemeanor.
It is a Class 2 misdemeanor at any time for a person to drive or operate a motor vehicle upon the national system of interstate highways at a speed less than forty miles per hour unless such vehicle is so operated pursuant to a permit, issued by the Department of Transportation.
Source: SDC Supp 1960, §44.0303 (8) as added by SL 1963, ch 253; SL 1964, ch 123, §1; SL 1989, ch 255, §125.