Thanks Jeff, for making sense of those arcane I.C.C. rules and decisions. I have read of various financially troubled Eastern railroads making the special effort to return " foreign road " empties to their designated interchange point BEFORE MIDNIGHT, to avoid having to pay another days' per diem. Also, when E.H. Harriman created Pacific Fruit Express it was decided the 1 cent per car mile rate would apply to empty as well as loaded reefers, as an incentive to return empties promptly to a PFE interchange point.