title: A comparative study of count models: application to pedestrian-vehicle crashes along Malaysia federal roads.
abstract: OBJECTIVE
  The objective of this study was to examine the effects of various roadway characteristics on the incidence of pedestrian-vehicle crashes by developing a set of crash prediction models on 543 km of Malaysia federal roads over a 4-year time span between 2007 and 2010.
  
  
  METHODS
  Four count models including the Poisson, negative binomial (NB), hurdle Poisson (HP), and hurdle negative binomial (HNB) models were developed and compared to model the number of pedestrian crashes.
  
  
  CONCLUSIONS
  The results indicated the presence of overdispersion in the pedestrian crashes (PCs) and showed that it is due to excess zero rather than variability in the crash data. To handle the issue, the hurdle Poisson model was found to be the best model among the considered models in terms of comparative measures. Moreover, the variables average daily traffic, heavy vehicle traffic, speed limit, land use, and area type were significantly associated with PCs.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Hosseinpour
authors.affiliation: School of Civil Engineering , Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia. h_mehdi61@yahoo.com
authors.forename: Mehdi Hossein
authors.initials: MH
authors.lastname: Pour
authors.forename: Joewono
authors.initials: J
authors.lastname: Prasetijo
authors.forename: Ahmad Shukri
authors.initials: AS
authors.lastname: Yahaya
authors.forename: Seyed Mohammad Reza
authors.initials: SM
authors.lastname: Ghadiri
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D016010:Binomial Distribution; D004779:Environment Design / Q000706:statistics & numerical data*; D006801:Humans; D008296:Malaysia; D015233:Models, Statistical; D016012:Poisson Distribution; D015203:Reproducibility of Results; D016138:Walking / Q000293:injuries*