U.S. passenger railroad Amtrak will cancel all of its long-distance trains Thursday because of a potential freight rail strike that could start as soon as Friday.

Amtrak workers are not involved in the labor dispute, but Amtrak operates almost all of its 21,000 route miles outside the Northeast Corridor on track owned, maintained, and dispatched by freight railroads.

The latest trains that will be canceled starting Thursday are the Auto Train (Washington to Sanford, Florida), Capitol Limited (Washington to Pittsburgh), Cardinal (Washington to Chicago) and the Palmetto (south of Washington).

Some commuter trains like Chicago's Metra have also said they will be forced to begin cutting trains on Thursday.