Montana Title 61. Motor Vehicles § 61-8-704. Erection of signs--definition

(1) The operator of a motor vehicle may not be arrested under 61-8-703 unless signs have been placed at or near the state line on the primary highway system, outside towns or cities having over 2,500 population, and outside county seats on the primary highways to indicate the legal rate of speed.

(2) Any municipality that uses radio microwaves or another electrical device for law enforcement purposes shall erect and maintain appropriate signs giving notice of that use at a conspicuous place at or near the corporate limits of the municipality, upon each state highway and arterial street or highway entering the municipality, and at other places considered necessary by the municipal authorities for the information of the traveling public.

(3) Signs giving notice that the speed of vehicles may be measured by radio microwaves or other electrical device must be placed as required for speed signs in subsection (1). However, the absence of signs may not in itself invalidate an otherwise proper arrest.

(4) As used in this section, “arterial street” means any federal or state numbered route, controlled-access highway, or other major radial or circumferential street or highway designated by local authorities within their respective jurisdictions as part of a major arterial system or highway.