Railroaders use this prepositional shorthand on switch lists, track warrants, and radio chatter to identify a train by where it originated or last picked up cars. Dispatchers and yardmasters track inbound traffic based on these origin points to plan receiving tracks and crew changes. It immediately tells a crew what block of cars they are handling or which inbound drag they are waiting to pass.
Heard on the job
We can't get out of the siding until that ex-Chicago intermodal rolls by.
Insider tip
Using the origin city instead of the alphanumeric train symbol is common among yard crews who care more about where the freight came from than its corporate reporting code.