PRIORITY-BASED CLASSIFICATION FOR IMPROVING CONNECTION RELIABILITY IN RAILROAD YARDS. PART II OF II: DYNAMIC BLOCK TO TRACK ASSIGNMENT

A new method of sorting railcars in classification yards is proposed, where the goal is to ensure connections of particular cars to specific outbound trains. This ability would allow railroads to offer reliable service with a guaranteed origin-destination delivery time for each car. Sorting freight cars by both outbound train and destination yard block, rather than by destination yard block only, is proposed to allow railways to gain precision control over the makeup of each train. Cars can be scheduled through yards based on their delivery commitments, rather than on a first-in-first-out basis, so cars having no remaining schedule slack have first access to available train capacity. The paper describes the block to track assignment component of the Terminal Priority Movement Planner, a proof-of-concept decision support system field tested in 1994 at a classification yard and discusses lessons learned from this pilot test.