Investigating the relationship between freeway rear-end crash rates and macroscopically modeled reaction time. Issue 3 (2nd December 2022)

• Record Type: Journal Article
• Authors: Ahmed, Ishtiak; Williams, Billy M.; Samandar, M. Shoaib; Chun, Gyounghoon
• Is Part Of: Transportmetrica. Volume 18:Issue 3(2022)
• Page Start: 1001
• Page End: 1024
• Publication Date: 2022-12-02
• Subjects: Required reaction time -- car-following -- discontinuous traffic flow model -- rear-end crashes -- traffic stream stability; Transportation -- Periodicals; Transportation -- Research -- Periodicals; 388.072
• DOI: 10.1080/23249935.2021.1914769
• Languages: English
• ISSNs: 2324-9935

Abstract

Abstract : This study tests the hypothesis that an analytically estimated driver reaction time required for asymptotic stability, based on the macroscopic Gazis-Herman-Rothery (GHR) model, serves as an indicator of the impact of traffic oscillations on rear-end crashes. If separate GHR models are fit discontinuously for different traffic regimes, the local drop in required reaction time between these regimes can also be estimated. This study evaluates the relationship between rear-end crash rates and that drop in required reaction time. Traffic data from 28 sensors were used to fit the GHR model. Rear-end crash rates, estimated from four years of crash data, exhibited a positive correlation with the drop in required reaction time at the congested regime's density-breakpoint. A linear relationship provided the best fit. These results motivate follow-on research to incorporate macroscopically derived reaction time in road-safety planning. More generally, the study demonstrates a useful application of a discontinuous macroscopic traffic model.