Study Details

Study Title: Bayesian Analysis for Zero-Inflated Regression Models with the Power Prior: Applications to Road Safety Countermeasures

Authors: Jang et al.

Publication Date:MAR, 2010

Abstract: We consider zero-inflated Poisson and zero-inflated negative binomial regression models to analyze discrete count data containing a considerable amount of zero observations. Analysis of current data could be empirically feasible if we utilize similar data based on previous studies. Ibrahim and Chen (2000) proposed the power prior to incorporate certain information from the historical data available from previous studies. The power prior is constructed by raising the likelihood function of the historical data to the power a(0), where 0< or =a(0)or =1. The power prior is a useful informative prior in Bayesian inference. We estimate regression coefficients associated with several safety countermeasures. We use Markov chain and Monte Carlo techniques to execute some computations. The empirical results show that the zero-inflated models with the power prior perform better than the frequentist approach.

Study Citation: Jang, H., Lee, S., and Kim, S. W., "Bayesian Analysis for Zero-Inflated Regression Models with the Power Prior: Applications to Road Safety Countermeasures." Accident Analysis and Prevention, Vol. 42 (2010) pp. 540-547.


CMFs Associated With This Study

Category: Alignment

Countermeasure: Increase in horizontal curvature from X to Y degrees (assuming 100 meter arc length)

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
CMF EquationCRF Equation1 StarAllAllNot SpecifiedRural

Category:Roadside

Countermeasure: Install Guardrail (unspecified hazard)

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.42582 StarsAllAllNot SpecifiedRural

Countermeasure: Install median barrier

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.23772 StarsAllAllNot SpecifiedRural