Development of Safety Performance Functions for Restricted Crossing U-Turn Intersections

Abstract

Conventional intersection designs are known to be problematic and unreliable when handling the complexity associated with the heavy traffic volume and travel demand on today’s roadways. Alternative innovative and safer designs such as the restricted crossing U-turn (RCUT) intersection can address these complex problems. However, there is still a gap in the literature concerning the safety performance analysis of RCUT intersections. Consistent with this goal, a comprehensive search was performed to identify RCUTs in the US and collect the relevant data needed to create appropriate safety performance functions and crash modification factors/functions for RCUTs. As such, different safety performance function (SPF) and crash modification factors/function (CMF) models were developed for signalized and unsignalized RCUTs with a focus on all crashes or fatal and injury crashes only, which span from complex models to relatively simple and easily implementable models. This can aid in creating a flexibility for safety agencies or officials that can prefer more complex models when sufficient data are available. Findings indicate that RCUTs have the potential to reduce the number of fatal and injury (F&I) crashes substantially at problematic locations and specifically illustrate that the selection of RCUT location depends significantly on the traffic volumes of major and minor approaches as well as their ratios. The developed SPFs and CMFs can be successfully used by transportation agencies to make informed decisions on the evaluation and justification of the installation of RCUTs.