Citation

Oppenlander JC. Highw. Res. Board bull. 1962; 341: 77-91.

Copyright

(Copyright © 1962, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A rational technique was developed designed to ascertain scientific warrants for the regulation of vehicular speeds. The investigation was predicated on the need for an engineering approach to an important problem in the operation of the highway transportation system--proper speed limits. Speed regulations can be developed for any given highway or street location by using the following procedure: (1) the optimal speed that minimizes the cost of highway transportation is first selected, (2) the adjusted speed is derived from the optimal speed by subtracting the reduction in speed occasioned by those driver, vehicle, roadway, traffic, and environmental variables that significantly modify vehicular speeds (which technique accounts for those conditions that differ from the ideal travel conditions for which the optimal speed is determined), and (3) statistical relationships between the upper and lower speed limits and the adjusted speed produce the posted speed regulations. The actual mean speed of the traffic stream should conform to the adjusted speed as the result of proper enforcement and driver education. Statewide speed limits can be evolved from the first and third steps for different vehicle types during daytime or nighttime travel on various roadway facilities in different areas of traffic operation. A technique employing all three steps permits the designation of speed limits (regulatory or advisory) for highway and street locations where various physical and environmental factors influence traffic-stream conditions.