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 the vehicle is operated pursuant to a permit, issued by the Department of Public Safety. This section does not apply to highway equipment operated by personnel in the performance of highway maintenance duties.

Source: SDC Supp 1960, § 44.0303 (8) as added by SL 1963, ch 253 ; SL 1964, ch 123 , § 1; SL 1989, ch 255 , § 125; SL 2022, ch 100 , § 1.