Contributory factors to truck crashes considering enforcement types, accounting for the enforcement endogeneity

Abstract

AbstractThe U.S. economy depends on trucking industry for timely delivery of goods and product. However, the performance of the industry has been crippled by the tremendous costs of crashes. Despite the efforts in studying factors leading to truck crashes, a comprehensive study considering enforcement efforts on the safety of the trucking industry is very limited. Thus, this study contributes to the body of knowledge by studying underling factors causing truck crashes, while considering various types of citations. To account for subjectivity of the highway patrol in allocating their resources to specific locations, such as adjustment of their locations to better capture the violators, we considered the interaction terms between citation types and various geometric characteristics. That is especially important as the majority of past studies ignored the endogeneity of highway patrol in allocating the resources to particular locations. Also, to account for both aspects of truck crashes, including severity and frequency, equivalent property damage only were used as the response. The results highlighted, for instance, that interaction terms between commercial motor vehicle citations and presence of horizontal curve, or the interaction between the curve length and speed‐related citations are factors impacting the safety of truck‐related crashes. The results provided evidence that indeed highway patrol allocates their resources to locations with particular geometric characteristics, and ignoring those interaction terms is likely to result in biased point estimates. We discuss the implications of the findings that solely highlighting that the enforcement resources are negatively or positively correlated with crashes could not provide much information, and the inclusion of particular enforcement types with related interaction term could help highway patrol to amend their performance based on their discretion.