Section 17C-6-3a - Minimum speed regulations; penalty(a) No person shall drive a motor vehicle at such a slow speed as to impede the normal and reasonable movement of traffic except when reduced speed is necessary for safe operation or in compliance with law.(b) Whenever the commissioner or local authorities within their respective jurisdiction determine on the basis of an engineering and traffic investigation that slow speeds on any part of the highway consistently impede the normal and reasonable movement of traffic, the commissioner or such local authority may determine and declare a minimum speed limit below which no person shall drive a vehicle except when necessary for safe operation or in compliance with law.(c) Any person who violates the provisions of this section is guilty of a misdemeanor and, upon conviction thereof, shall be fined not more than one hundred dollars; upon a second conviction within one year thereafter, shall be fined not more than two hundred dollars; and upon a third or subsequent conviction within two years thereafter, shall be fined not more than five hundred dollars.