VIA used to run trainsets in from Mimico in bunches, usually with a loco leading, They also used to have a reverse loop right at Union, but they sold it off for a football stadium.
The Canadian at one point ran in a big loop, starting north of Lake Simcoe, coming south down one side, through Union, then north up the other side.Then the track through Barrie was abandoned and they had to use the one track both ways, but they still started north aimed at Barrie and did a messy back and forth movement to reach the other sub (backing through the curves at one junction). Not sure what happens now.