title: Competing risks mixture model for traffic incident duration prediction.
abstract: Traffic incident duration is known to result from a combination of multiple factors, including covariates such as spatial and temporal characteristics, traffic conditions, and existence of secondary accidents but also the clearance method itself. In this paper, a competing risks mixture model is used to investigate the influence of clearance methods and various covariates on the duration of traffic incidents and predict traffic incident duration. The proposed mixture model considers the uncertainty in any of five clearance methods that occurred. The probability of the clearance method is specified in the mixture by using a multinomial logistic model. Three candidate distributions, namely, generalized gamma, Weibull, and log-logistic are tested to determine the most appropriate probability density function of the parametric survival analysis model. The unobserved heterogeneity is also incorporated into the mixture model in a way that allows parameters to vary across observations based on the three candidate distributions. The methods are illustrated with incident data from Singaporean expressways from January 2010 to December 2011. Regression analysis reveals that the probability of different clearance methods and the duration of traffic incidents are both significantly affected by various factors, such as traffic conditions and incident characteristics. Results show that the proposed mixture model is better than the traditional accelerated failure time model, and it predicts traffic incident duration with reasonable accuracy, as shown by the mean average percent error.
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA 0219, USA; Department of Civil Engineering, Tsinghua University, Beijing, 100084, China. Electronic address: lrmin@tsinghua.edu.cn.
authors.forename: Ruimin
authors.initials: R
authors.lastname: Li
authors.affiliation: Singapore-MIT Alliance for Research and Technology (SMART), 1 CREATE Way, #09-02 CREATE Tower, Singapore 138602, Singapore. Electronic address: camara@smart.mit.edu.
authors.forename: Francisco C
authors.initials: FC
authors.lastname: Pereira
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Room 1-181, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. Electronic address: mba@mit.edu.
authors.forename: Moshe E
authors.initials: ME
authors.lastname: Ben-Akiva
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D006801:Humans; D008962:Models, Theoretical; D012044:Regression Analysis; D012306:Risk; D012846:Singapore; D016019:Survival Analysis; D013997:Time Factors
keywords: Competing risks; Mixture model; Traffic incident duration prediction; Traffic incident management