Highway-rail grade crossing safety: An examination of view obstruction and crossing angle using aerial photography

This study examines how characteristics of highway-rail grade crossings contribute to intersection collision frequency. Specific attention is focused on view obstructions. A view obstruction refers to any object that blocks line-of-sight between the driver of a motor vehicle and the path of the train. The analysis is based on a sample of highway-rail grade intersections drawn from a collision dataset compiled by the Federal Railroad Administration (FRA). Roughly two-thirds of the intersections were sites of collisions. These are contrasted to a control group of intersections having had no recorded train-automobile collisions. Line-of-sight data were developed from measurements and imagery obtained in GIS. Driver visibility is characterized in terms of two attributes: track angle and distance to the obstructing object. Other characteristics of the rail-highway intersection are drawn from the FRA database. A logistic regression models the likelihood of a train-automobile collision (drawn from historic FRA data) against characteristics of the grade crossing intersection, including the derived attributes of angle and distance to visual obstructions.