Demonstration Project No. 70, Railroad Crossing Corridor Improvements, was developed to encourage State highway agencies to expand their current efforts to encompass significantly more crossings each year by including low-cost improvements at the types of crossings that are not presently being addressed. This report summarizes corridor reviews that were held in six States (Iowa, Florida, Alaska, West Virginia, Louisiana, and California) in late 1985 and early 1986. The final chapter presents a model program which combines the benefits of current individual high-risk crossing programs with those of a corridor approach in which a series of adjacent crossings are reviewed by a diagnostic team.