Whenever the board finds and determines upon the basis of an engineering and traffic
survey that the speed limit of 65 miles per hour is more than is reasonable or safe
upon any portion of the highway where such speed limit of 65 miles per hour is applicable
under the State Vehicle Code, and further determines that a speed of 60, 55, 50, 45,
35 or 25 miles per hour is more appropriate to facilitate the orderly movement of
traffic and is reasonable and safe, the commissioner shall post the appropriate signs
upon such highways specifying such speed limits of 60, 55, 50, 45, 40, 35, 30 or 25
miles per hour as the case may be.
