• Title/Summary/Keyword: ZIMB(zero-inflated negative binomial)

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Developing Rear-End Collision Models of Roundabouts in Korea (국내 회전교차로의 추돌사고 모형 개발)

  • Park, Byung Ho;Beak, Tae Hun
    • Journal of the Korean Society of Safety
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    • v.29 no.6
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    • pp.151-157
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    • 2014
  • This study deals with the rear-end collision at roundabouts. The purpose of this study is to develop the accident models of rear-end collision in Korea. In pursuing the above, this study gives particular attention to developing the appropriate models using Poisson, negative binomial model, ZAM, multiple linear and nonlinear regression models, and statistical analysis tools. The main results are as follows. First, the Vuong statistics and overdispersion parameters indicate that ZIP is the most appropriate model among count data models. Second, RMSE, MPB, MAD and correlation coefficient tests show that the multiple nonlinear model is the most suitable to the rear-end collision data. Finally, such the independent variables as traffic volume, ratio of heavy vehicle, number of circulatory roadway lane, number of crosswalk and stop line are adopted in the optimal model.