Investigating different approaches to develop informative priors in hierarchical Bayesian safety performance functions

    Authors

    R. J. Yu;M. Abdel-Aty

    Comments

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    Abbreviated Journal Title

    Accid. Anal. Prev.

    Keywords

    Informative prior; Bayesian inference; Hierarchical Bayesian model; Safety performance functions; Weather and traffic data; FIXED DISPERSION PARAMETER; MOTOR-VEHICLE CRASHES; POISSON-GAMMA MODELS; SAMPLE-MEAN VALUES; MOUNTAINOUS FREEWAY; PERSPECTIVE; FREQUENCY; INFERENCE; SIZE; Ergonomics; Public, Environmental & Occupational Health; Social; Sciences, Interdisciplinary; Transportation

    Abstract

    The Bayesian inference method has been frequently adopted to develop safety performance functions. One advantage of the Bayesian inference is that prior information for the independent variables can be included in the inference procedures. However, there are few studies that discussed how to formulate informative priors for the independent variables and evaluated the effects of incorporating informative priors in developing safety performance functions. This paper addresses this deficiency by introducing four approaches of developing informative priors for the independent variables based on historical data and expert experience. Merits of these informative priors have been tested along with two types of Bayesian hierarchical models (Poisson-gamma and Poisson-lognormal models). Deviance information criterion (DIC), R-square values, and coefficients of variance for the estimations were utilized as evaluation measures to select the best model(s). Comparison across the models indicated that the Poisson-gamma model is superior with a better model fit and it is much more robust with the informative priors. Moreover, the two-stage Bayesian updating informative priors provided the best goodness-of-fit and coefficient estimation accuracies. Furthermore, informative priors for the inverse dispersion parameter have also been introduced and tested. Different types of informative priors' effects on the model estimations and goodness-of-fit have been compared and concluded. Finally, based on the results, recommendations for future research topics and study applications have been made. (C) 2013 Elsevier Ltd. All rights reserved.

    Journal Title

    Accident Analysis and Prevention

    Volume

    56

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    51

    Last Page

    58

    WOS Identifier

    WOS:000319633000005

    ISSN

    0001-4575

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