“…Logistic regression is a maximum-likelihood method that has been used in hundreds of studies of crash outcome (e.g., Hours et al, 2010;Robertson and Vanlaar, 2008;Schiff et al, 2008). For a binary response variable the linear logistic regression model, expressed in terms of the logit transformation of the ith individual's response probability, p i (e.g., probability of severe injury), is a linear function of the vector of explanatory variables or,…”