Effects of access, geometric design, and heterogeneous traffic on safety performance of divided multilane highways in India

Abstract

ABSTRACTSafety of the national highways (NHs) has been a major concern in India. Using 5 years of crash data from a 65-km stretch of a divided multilane NH, this study employs random parameter panel data models to identify factors affecting total crashes, rear-end and head-on crashes. Besides geometric design elements, this study focuses on the effect of access management strategies such as provision of service lane and presence of median opening on crash types. To capture the effect of mixed traffic on crash occurrence, vehicle composition is considered in addition to average daily traffic (ADT). Results suggest that the effects of segment length and ADT are generally fixed and consistent across crash types, but there exists variation in safety performance of horizontal alignment, access management strategies, and type of vehicles. Although the coefficient for proportion of motorized two wheelers is found to be random for rear-end crashes, higher proportions of truck traffic are found to be always associated with higher head-on collisions. Although segments with service lanes are associated with fewer rear-end and head-on crashes, median opening presence is found to increase both of these crash types even though the effect on total crashes is random.