TY - JOUR PY - 2006// TI - Bayesian Multivariate Poisson Regression for Models of Injury Count, by Severity JO - Transportation research record A1 - Ma, Junlai A1 - Kockelman, Kara Maria SP - 24 EP - 34 VL - 1950 IS - N2 - In practice, crash and injury counts are modeled by using a single equation or a series of independently specified equations, which may neglect shared information in unobserved error terms, reduce efficiency in parameter estimates, and lead to biases in sample databases. This paper offers a multivariate Poisson specification that simultaneously models injuries by severity. Parameter estimation is performed within the Bayesian paradigm with a Gibbs sampler for crashes on Washington State highways. Parameter estimates and goodness-of-fit measures are compared with a series of independent Poisson equations, and a cost-benefit analysis of a 10-mph speed limit change is provided as an example application.

LA - en SN - 0361-1981 UR - http://dx.doi.org/ ID - ref1 ER -