Interswitching adds into the system the ability for captive shippers to have access to another railway. There are designated interchange points at which the first railway would bring the goods to the interchange point at a regulated rate—now that's out to 160 kilometres—and hand it off to the other railway with which the shipper has contracted.
It really is a provision that allows for access to an additional railway. It's used in making that switch and is also a provision in the legislation allowing those who are using the transportation system to negotiate with that possibility in play.