Until there is an Obico Subway yard in place, any new subway cars will be truck in. Once a new Obico yard is up and running, you could ship by rail and reduce the need for escort all the way from X. Regardless if ship by rail or truck, they still have to be put together to make a train. If the new cars can be shipped by rail, more than one car can be ship to the yard with TTC moving cars to the ramp area as needed, not the way it was done for the streetcars. One track would hold all the new cars until they can be off loaded with the empty being move to another track using a track module unit.
Can not see CN delivering cars to the north extension since the line and yard will be underground in the first place. Don't see a branch line being built off CN line into a tunnel to get to the yard. Don't know if the yard would ne able to put a train together there or have to be pull all the way to Wilson. If they have to be pull to Wilson, you are far better off shipping by truck straight to Wilson like it was done for the TR.
The question is, will the new yard be built and in operation before the new cars are order and being delivery? Until that yard is in operation, trucks will be delivering the next new fleet of TR's.
Trucks will be use to delivery the Finch and Hurontario streetcars since there is no rail connection near the yards.