title: A Hybrid Latent Class Analysis Modeling Approach to Analyze Urban Expressway Crash Risk.
abstract: Crash risk analysis is rising as a hot research topic as it could reveal the relationships between traffic flow characteristics and crash occurrence risk, which is beneficial to understand crash mechanisms which would further refine the design of Active Traffic Management System (ATMS). However, the majority of the current crash risk analysis studies have ignored the impact of geometric characteristics on crash risk estimation while recent studies proved that crash occurrence risk was affected by the various alignment features. In this study, a hybrid Latent Class Analysis (LCA) modeling approach was proposed to account for the heterogeneous effects of geometric characteristics. Crashes were first segmented into homogenous subgroups, where the optimal number of latent classes was identified based on bootstrap likelihood ratio tests. Then, separate crash risk analysis models were developed using Bayesian random parameter logistic regression technique; data from Shanghai urban expressway system were employed to conduct the empirical study. Different crash risk contributing factors were unveiled by the hybrid LCA approach and better model goodness-of-fit was obtained while comparing to an overall total crash model. Finally, benefits of the proposed hybrid LCA approach were discussed.
authors.affiliation: Road and Traffic Key Laboratory, Ministry of Education, Shanghai 201804, China; College of Transportation Engineering, Tongji University,4800 Cao'an Road, Shanghai 201804, China.
authors.forename: Rongjie
authors.initials: R
authors.lastname: Yu
authors.affiliation: Road and Traffic Key Laboratory, Ministry of Education, Shanghai 201804, China; College of Transportation Engineering, Tongji University,4800 Cao'an Road, Shanghai 201804, China. Electronic address: wangxs@tongji.edu.cn.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Civil, Environmental and Construction Engineering, University of Central Florida Orlando, FL 32826-2450, United States.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdel-Aty
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D001499:Bayes Theorem; D002681:China; D004779:Environment Design; D006801:Humans; D016015:Logistic Models; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014505:Urban Population
keywords: Bayesian random parameter model; Crash risk analysis; Latent class analysis; Unobserved heterogeneity