Further notes on the application of zero-inflated models in highway safety

Accid Anal Prev. 2007 Jan;39(1):53-7. doi: 10.1016/j.aap.2006.06.004. Epub 2006 Sep 1.


The intent of this note is to succinctly articulate additional points that were not provided in the original paper (Lord et al., 2005) and to help clarify a collective reluctance to adopt zero-inflated (ZI) models for modeling highway safety data. A dialogue on this important issue, just one of many important safety modeling issues, is healthy discourse on the path towards improved safety modeling. This note first provides a summary of prior findings and conclusions of the original paper. It then presents two critical and relevant issues: the maximizing statistical fit fallacy and logic problems with the ZI model in highway safety modeling. Finally, we provide brief conclusions.

Publication types

  • Review

MeSH terms

  • Accidents, Traffic / statistics & numerical data*
  • Binomial Distribution
  • Humans
  • Poisson Distribution
  • Regression Analysis
  • Safety / statistics & numerical data*
  • Transportation / standards*