Dividing train

A dividing train is a passenger train that separates into two trains partway along its route, so as to serve two destinations. Inversely, two trains from different origins may be coupled together mid-route to reach a common endpoint. Trains on complex routes may divide or couple multiple times. The general term for coupling two or more trains along their shared route sections is portion working.

For example, the westbound Empire Builder travels from Chicago Union Station to Spokane, Washington, where its cars are divided into two trains: one continues to Portland Union Station and one to King Street Station, Seattle. On the eastbound trip, trains from Portland and Seattle are coupled at Spokane before traveling as one train to Chicago.

Dividing trains are useful where line capacity is limited, allowing multiple trains to use the same path over a congested part of a network. The common sections will often be the busiest parts of the routes.