New Mexico Statutes Chapter 66. Motor Vehicles § 66-7-305. Minimum speed regulation

A. A person shall not 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 to be in compliance with law.

B. Whenever the state transportation commission or local authorities within their respective jurisdictions determine on the basis of an engineering and traffic investigation that slow speeds on any part of a highway consistently impede the normal and reasonable movement of traffic, the commission or the 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 to be in compliance with law; provided that local authorities in municipalities of more than one hundred thousand population may prohibit vehicles that by virtue of weight or design are slow moving on local arterials during peak hours of traffic.