RSA 265:62 Establishment of State Speed Zones.

I. Whenever the commissioner of transportation shall determine, upon the basis of an engineering and traffic investigation, or in the event of vehicle or weather emergencies, that any prima facie speed limit hereinbefore set forth is greater or less than is reasonable or safe under the conditions found to exist at any intersection or other place or upon any part of the state highway system, outside the compact part of cities or towns, said commissioner may determine and declare a reasonable and safe prima facie speed limit thereat which shall be effective when appropriate signs giving notice thereof are erected. Such signs may carry either a fixed speed limit legend or a changeable message so designed as to permit display of different speed limits at various times of the day or nigh