Safety Evaluation Effect of Variable Speed-Limit Control System Based on the Empirical Bayesian Model

摘要

The highway safety evaluation method based on empirical Bayes is put forward in order to make quantitative analysis of the influence of variable speed system on expressway traffic accidents. A control group and a reference group are introduced, with the empirical Bayes model to predict the number of traffic accidents in the facilities group without variable speed limit signs being installed, then to determine the rate drop in traffic accidents after the installation of variable speed limit signs, and to avoid the problem of accident data of mean reversion. Based on the data of the 476 traffic accidents of Xibao Highway and Baohan Highway in Shaanxi Province, the case analysis results show that the traffic accident rate decreased by about 32% on average with the installation of a variable speed system. The highway safety evaluation methods are more persuasive than the before-and-after evaluation method.