A Framework for Assessing Models that Rank Highway-Rail Grade Crossings for Improvement

In the Midwest, three states in recent years have re-examined their grade crossing model. Illinois conducted a study that developed a new model, the expected accident frequency formula, using a nonlinear regression analysis procedure. Kansas also recently re-examined their model and replaced their design hazard rating formula with a simpler one developed for New Hampshire. Finally, the Missouri Department of Transportation began a similar assessment in 2001. In this paper, we present a framework for assessing grade-crossing models and selecting a preferred model. The methodology consists of five steps that can be adapted to fit most any situation. After presenting this framework, we apply it to Missouri’s evaluation of its exposure index. A major strength of the five-step approach is that it brings together key stakeholders and involves them in the process of establishing characteristics of the “best” model. This dialog strengthens the credibility of any decision to keep or revise a state’s grade crossing model. We are confident that the five-step framework used in this study can be used by any agency seeking to upgrade its grade crossing model.