While the transit authority owns the railway lines, private companies owns the trains that would transport shipping containers. The private company must also have their own engine. They are responsible for maintenance, and the vehicles must be reliably running. If they are having problems while on the tracks, they must be replaced as quickly as possible to prevent a train from breaking down on the tracks. Freight trains are likely to operate at night, and will give preference to passenger trains. Since passenger trains always have priority, they will always go first when using the same tracks as the freight line.