I think the traditional concept of the railroad yard, at least on a divisional or local level, has pretty much faded. In my lifetime, trains seem to have grown from around 50 cars / 5,000 tons / 3,500 feet to today's monsters at 110 cars / 15,000 tons and 7,000+ feet. It used to be must crew changes had a big enough yard to be able to yard several trains during a MOW window, holiday, waiting for rested crews or other interruptions. These yard tracks have disappeared for a variety of reasons: failure to maintain and upgrade, too short in today's world, property taxes or just due to stupidity. Most of today's trains are restricted to trying to fit wherever they can close to a terminal, hopefully without cutting any crossings or tying down a zillion handbrakes, or pissing off the neighbors with idling/restarting diesels.

Basic problem is this - all these college kid managers (no practicable on the ground experience) and bean counters were quick to point out how much labor could be eliminated by running DPU and monster trains, but did not take into account, admit to or were even aware of the need to make the other improvements needed to keep the railroad fluid.

Could you imagine most of today's railroaders trying to run trains in dark territory with retainers, train orders/timetables, flagging, no radios and all the while dodging multiple passenger and superior trains rarely delaying them? I know railroads are more efficient in today's world, but they are still missing the mark in safety and efficiency in my opinion.