The scenario: BNSF Argentine Yard in Kansas City is a disaster (according to the dispatcher), and trains are backed up for forty miles on each side, waiting for their turn to get into the yard. BNSF 4242 West is pulling sixty loaded auto racks but is behind five other trains. It stops short of CA Jct. around the corner ahead, so as not to block any road crossings. BNSF 7972 West is a priority Z-train which will bypass Argentine Yard with no more than a crew change and possibly some fuel, before continuing on to Logistics Park Kansas near Gardner. Railroad union work rules decree that although the crews on the delayed trains may not reach the yard for many hours, the trains which pass them also advance their position on the call list for future trains, even ahead of the crews which pass them. On the BNSF, that happens all the time, even with trains which are not delayed except for allowing trains with higher priorities to pass them along the way.