Citation

Ogawa T, Fisher ES, Oppenlander JC. Highw. Res. Board bull. 1962; 341: 18-29.

Copyright

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

DOI

unavailable

PMID

unavailable

Abstract

Expedient and safe operation of traffic on various highways and streets has necessitated regulation of motor vehicle speeds. Before scientific warrants can be developed for determination of proper and reasonable speed limits, driver response to regulatory speed limit signs must be ascertained to evaluate the effectiveness of these traffic control devices in modifying vehicular speeds. This field investigation was designed to measure the influence of speed limits on individual drivers speed characteristics in a series of contiguous rural and urban areas. The roadway traveled by the observed drivers was relatively homogeneous in the rural areas. Uniformity of travel existed in the urban centers with the exception of different posted speed regulations. Analyses of the speed data by appropriate statistical techniques indicated that speed limit signs had relatively little effect in regulating both the central tendency and the variability of vehicle speeds at urban locations. However, these signs were no doubt effective as a means of advising motorists of prevailing speed conditions. This inference concerning the effectiveness of regulatory speed signs was the result of a before-and-after study made to evaluate the influence of altering speed limits in the urban areas. There was some uniformity in the speed habits of individual drivers in the five rural areas, but little consistency existed in their speeds of travel in the four urban areas. In addition, no significant relationship existed between the individual driver's speeds in rural and urban areas. A fast driver in rural areas was not necessarily a fast driver in urban areas, and vice versa. The condition of chronic speeding was not observed to any marked degree as the individual drivers exceeding the urban and rural speed limits varied from one location to another. Finally, results of statistical tests showed that variations of spot speeds with time of day were not consistent with respect to both times of the day and locations along the study route.