Doing a direct way from Toronto,to Quebec city is a bit complicated to do..
Fisrt,the way the track are done,we have no choice to get in and after,do a back-up to get out,but by leaving a light loco on the right way at the station and use it to get off on the other way could be faster,but,passenger will be contract to do the second part of the ride by backward way,peopple will say that must have to turn the seats..
By back-ing up to continue,the train have to do the back up pretty far,by using the same way,to swith,but have to back-up a bit over the Welligton CN bridge,near PSC yard and after,move back on foward to pass behind the yard and take Victoria bridge.
The second way is to skip the Montreal Central station,but need to built a new station near Victoria bridge,the require a bus service to do the shuttle between Montreal Central station to the other station,it's a lot of thing to do..
By the same,By asking the question directly to a VIA Rail employee,I get for answer that the trains can't to the direct ride,cause lot of passenger does'nt go to Quebec and the ones wo want to go to have to transfert of train..
First,the train is fusbrished to do a specific ride,so,on the way,they could be on shortage of food,drinks or alcool..
And by making stop al the trains to the Montreal Central station,that make a chance to the travelers to have a lunch,cigarette and get a short remain time,to get a little walk,sometime,when sitting 4 or 5 hours of time,peopple need to walk a bit to strech threir legs a little bit..
Probably,If the governement finally realise the TGV line,that could be possible to see a direct connection from Windsor to Quebec city.But for the TGV,we could dream about it for a while...
And VIA Rail still using LRC car on Montreal-Quebec trains,at least,once a day..
VIA 27 have most of the time,LRC car...
I did the ride a few times,here on of them,where I shooted some videos from the train..
http://www.youtube.com/watch?v=b_PBvJOla4s