First and foremost
Carl can most likely give us much more information here, but in the western 'burbs of Chicagoland we have the U.P. mainline and between Rochelle and Chicago there are usually very many eastbound freights sitting in the "parking lot" waiting for access to the various metro yards and/or transition to one of the other railroads like the EJ&E, BRC, etc.
Carl, care to add to this?
Eolafan (a.k.a. Jim)
