Shortlines, Industries, and Empties

[Brakie]

No railroad is in business to store locomotives or rolling stock, and especially not someone else's rolling stock.

Actually, don't some shortlines make money by storing other lines' cars?

Yes many do charge a fee for storing cars..

However,

If a normal empty foreign road car isn't returned to its home rails then the railroad that still has that car on its rails gets stuck paying a Demurrage fee for holding that car...This is why empty foreign road cars are quickly returned to their home rails or pass on to the next direct route connecting road which becomes responsible for returning that car.