Civil and Environmental Engineering Commons^™

Validation And Implication Of Segmentation On Empirical Bayes For Highway Safety Studies, Reginald R. Souleyrette, R. P. Haas, Thomas H. Maze

Reginald R. Souleyrette

Typically, crash frequency is modelled as Poison where the variation is the square root of the expected number. If the expected number of crashes is small, the variation is a large percentage of the expected number of crashes, and the observed number of crashes provides a crude estimate for the expected number. A better estimate is obtained when the expected number is large. For a specific location, there are two approaches for performing measurements where the expected number of crashes is large. One approach is to measure over a long period of time. However, data are not often available for …