A Comparative Study of Count Models: Application to Pedestrian-Vehicle Crashes Along Malaysia Federal Roads

Abstract

Objectives: 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.

Results and 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.

Keywords:

• vehicle–pedestrian crashes
• count models
• overdisperion
• hurdle model
• model selection criteria.

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Corrigendum

Acknowledgments

The authors thank the Malaysia Institute of Safety Research and the Highway Planning Unit for the data used in this research. This study is part of a research project sponsored by the Universiti Sains Malaysia, and their support and assistance is greatly appreciated.