Semi-fantasy proposal:
The track between Guelph and Georgetown is terrible, a single-track line with poor track quality, outdated signals, sharp turns and tons of level crossings. As we want to implement decent service between Kitchener and Toronto, the line would need to be upgraded, but most of the sharp curves are within towns, so widening them is not an option. Even with banked corners, I doubt those curves could be taken at more than
45mph (EDIT: 80mph).
Rather than spending tons of money to upgrade the GEXR Guelph sub, Metrolinx can use that money to build an entirely new rail line between Guelph and Georgetown. It could be built to medium high-speed standard (125-160mph, 200-260km/h) in anticipation of higher speed rail on the corridor. The Electrification report recommended electrifying as far as Georgetown, but if we build this rail line, it would be silly not to electrify it as well.
Below is the proposed route in purple, with the existing line in green.
full size image
Where the line splits off in Guelph, there happens to be a perfectly positioned vacant corridor for it to run through. The sooner the line is built, the less likely it is that something will get built in that corridor.
Once GO starts running electric trains, the line will begin to be used to its full potential. While our current VIA/GO trains have top speeds of 110mph/93mph (177km/h; 150km/h), most new electric locomotives have a top speed of at least 125mph (200km/h).
Trip times between Guelph and Georgetown would be cut from 26min (VIA) to 12min.
If trains also skip Georgetown station, travel time from Guelph to Brampton would drop from 37min to 20min.*
*Numbers are calculated based on Northeast Corridor services between stops a similar distance apart, with line speeds of 125mph/135mph (Northeast Regional/Acela). Trains stopping in Georgetown are assumed to have a top speed of 125mph, and trains skipping Georgetown are assumed to have a top speed of 135mph.