GO Transit

[Bytor]

Of course, I think we should have both Guelph and Milton, and the Lakeshore West Hamilton→Brantford extension that takes back the Paris rail trail and loops up to Cambridge.

You don't have to take back the Cambridge to Paris rail trail, the old line through Branchton and Harrisburg to Lyndon will get you to the same spot in Cambridge without the time consuming jog through Brantford. Will it ever happen? No.

You can have trails beside active rail lines. You could easily shift the walking trail over with enough width for double-tracking all the way from Cambridge to Paris.

And with a proper 110mph (177km/h) intercity rail system, it's not a time-consuming jog through Brantford.

Cambridge → Paris ~21km, ~8 minutes
Paris → Brantford, ~12km, ~6 minutes
Brantford → Hamilton, ~36km, ~13 minutes, using the Hamilton-Brantford rail trail right of way.

With a 1 minute dwell time at Paris and Brantford, that's 29 minutes.

Going through Branchton, Harrisburg and Lynden instead 

Cambridge → Harrisburg Wye, 22km, ~8 minutes
Harrisburg Wye, 2km, 2 minutes
Harrisburg Wye → Lynden ~6km, ~ 4 minutes
Lynden→Hamilton, ~30km, ~14 minutes

With a 1 minute well time at Lynden, that's also 29 minutes. Again, the 90° curves around the RBG and Main / Dundurn, but also a very tight wye track at Harrisburg to turn towards Lynden which reduces one's speed significantly. And that means from the wye to Lynden the train can only get up to ~55mph (87km/h) instead of 110mph.

I rounded the Lynden mileage down and the Brantford route up, and it also depends on the actual geometry of what that wye through Harrisburg was, which I was also generous as to speed for it. It could ad as much as 5 minutes instead of 2 onto the Cambridge to Lynden portion.

So, overall, If both routes existed with modern electric inter-city rail, you'd probably get to Hamilton 5 minutes faster going through Brantford if all these rails had not been abandoned and had been kept in use and upgraded over time.