Impact of Hourly Measured Speed on Accident Risk in the Netherlands

Abstract

Several scholars have defined the urgent need for more research to identify more fully the precise relationship between speed and crash involvement. This paper presents the first results of an exploratory study carried out in the Brabant Southeast police region in the Netherlands. Hourly speed measurement data over a period of 2 years were collected from loop detectors on the municipal and provincial road network and were related to crashes. Different aspects of traffic intensity, speed, and their impact on crashes, including absolute speed, speed variation, and the proportion of excessive speeders, for vehicles less than and more than 5.2 m long, were studied. The study also discusses a number of methodological aspects associated with this kind of analysis. The results show that although absolute speed plays a more important role on roads where speed limits are low, the variation in speed correlates more with crashes when speed limits are higher. Given the limited study area, the results of this work cannot be generalized without risk. However, they offer interesting insights that deserve further investigation in a nationwide cross-sectional study.