File(s) under permanent embargo

Reason: This item is currently closed access.

Applying the random effect negative binomial model to examine traffic accident occurrence at signalized intersections

journal contribution
posted on 04.09.2009, 09:02 by Hoong Chor Chin, Mohammed A. Quddus
Poisson and negative binomial (NB) models have been used to analyze traffic accident occurrence at intersections for several years. There are however, limitations in the use of such models. The Poisson model requires the variance-to-mean ratio of the accident data to be about 1. Both the Poisson and the NB models require the accident data to be uncorrelated in time. Due to unobserved heterogeneity and serial correlation in the accident data, both models seem to be inappropriate.Amore suitable alternative is the random effect negative binomial (RENB) model, which by treating the data in a time-series cross-section panel, will be able to deal with the spatial and temporal effects in the data. This paper describes the use of RENB model to identify the elements that affect intersection safety. To establish the suitability of the model, several goodness-of-fit statistics are used. The model is then applied to investigate the relationship between accident occurrence and the geometric, traffic and control characteristics of signalized intersections in Singapore. The results showed that 11 variables significantly affected the safety at the intersections. The total approach volumes, the numbers of phases per cycle, the uncontrolled left-turn lane and the presence of a surveillance camera are among the variables that are the highly significant.



  • Architecture, Building and Civil Engineering


CHIN, H.C. and QUDDUS, M.A., 2003. Applying the random effect negative binomial model to examine traffic accident occurrence at signalized intersections. Accident Analysis and Prevention, 35(2), pp. 253-259


© Elsevier


NA (Not Applicable or Unknown)

Publication date



This article is Closed Access. It was published in the journal, Accident Analysis and Prevention [© Elsevier] and is available at: