title: Examining driver injury severity in two vehicle crashes - a copula based approach.
abstract: A most commonly identified exogenous factor that significantly affects traffic crash injury severity sustained is the collision type variable. Most studies consider collision type only as an explanatory variable in modeling injury. However, it is possible that each collision type has a fundamentally distinct effect on injury severity sustained in the crash. In this paper, we examine the hypothesis that collision type fundamentally alters the injury severity pattern under consideration. Toward this end, we propose a joint modeling framework to study collision type and injury severity sustained as two dimensions of the severity process. We employ a copula based joint framework that ties the collision type (represented as a multinomial logit model) and injury severity (represented as an ordered logit model) through a closed form flexible dependency structure to study the injury severity process. The proposed approach also accommodates the potential heterogeneity (across drivers) in the dependency structure. Further, the study incorporates collision type as a vehicle-level, as opposed to a crash-level variable as hitherto assumed in earlier research, while also examining the impact of a comprehensive set of exogenous factors on driver injury severity. The proposed modeling system is estimated using collision data from the province of Victoria, Australia for the years 2006 through 2010.
authors: Department of Civil Engineering & Applied Mechanics, McGill University, Suite 483, 817 Sherbrooke St. W., Montréal, Canada. Electronic address: shamsunnahar.yasmin@mail.mcgill.ca.
authors: Shamsunnahar
authors: S
authors: Yasmin
authors: Department of Civil Engineering & Applied Mechanics, McGill University, Suite 483, 817 Sherbrooke St. W., Montréal, Canada. Electronic address: naveen.eluru@mcgill.ca.
authors: Naveen
authors: N
authors: Eluru
authors: Department of Civil and Environmental Engineering, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620, United States. Electronic address: apinjari@eng.usf.edu.
authors: Abdul R
authors: AR
authors: Pinjari
authors: Faculty of Business, Economics and Law, La Trobe University, Melbourne, Victoria 3086, Australia. Electronic address: r.tay@latrobe.edu.au.
authors: Richard
authors: R
authors: Tay
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D004777:Environment; D006801:Humans; D016015:Logistic Models; D015233:Models, Statistical; D012307:Risk Factors; D015599:Trauma Severity Indices
keywords: Copula methods; Injury severity profiles; Joint multinomial logit and ordered logit model; Two vehicle crashes