CAR MANAGEMENT OPPORTUNITIES: ACTUAL RETURN MILEAGE VERSUS OPTIMAL RETURN MILEAGE.

Recent developments in the research on car management currently undertaken by Princeton University under the sponsorship of the Association of American Railroads are described. The research makes extensive use of the Princeton Railroad Network Model and Information System. Car management opportunities are examined by comparing simulated actual empty return mileage (ARM) with optimal empty return mileage (ORM). ARM is the mileage obtained when empty cars that terminate on foreign roads are returned home under New Car Service Rule 2 (Rule 2) or Special Car Order 90 (SCO90) or both. ORM is the mileage obtained when empty cars that terminate on foreign roads are returned according to a cost (mileage-based) minimization criterion. The concept of ARM versus ORM is presented for the Southern Pacific Railroad by using 1980 1 percent waybill data for unequipped 50-ft boxcar traffic.