And when UP melted down circa 2004/2005, part of the problem was that Roseville was blocking trains for more locations than they had bowl tracks even before considering tracks out of service for maintenance or being pulled by a trim job.

I've always wondered if the practice of assigning cars as empties enroute makes sense? It used to be that a major yard only had to dump the common empties onto a few tracks. As the locals or haulers were made up, they could just grab X number of boxes, flats, hoppers, etc. to fill their work orders. Now most particular cars have to be not only assigned to a certain local or roadswitch but are already assigned to a particular customer instead of conductor's choice. Add all the private leased cars, and I think railroads have actually made loose/single car traffic far more inefficient than it needs to be.

Oh well, all the railroads really want to move are unit trains and those don't need no stinkin yards, switch engines or crews to be switched.