^It's hard to argue with him. I actually cant think of another GTA transit project in the past 30 years (outside of GO expansion) that was at least partially worth the investment.
I think the most significant project was Spadina ROW. Then there's Sheppard Subway.
Spadina streetcar and Sheppard subway are 6.2km and 5.5km lines with 44k and 50k boardings per weekday respectively. Mississauga Transitway won't come close. I doubt that, despite their much longer lengths, the future MiExpress 100, 107, 109 together will reach 44k or 50k (the 107 and 109 had close to 3k boardings combined in 2012).
No, I think the full potential of this transitway lies in 407 Transitway. Imagine a crosstown GO BRT spine for, between Mississauga and Markham and beyond, to complement the GO Trains to downtown (GO buses on the transitway will stop at 5 stations: Winston Churchill, Erin Mills, CCTT/Square One, Dixie, and Renforth).
But it is too bad the above-ground Eglinton Crosstown won't be full grade-separated like the Mississauga Transitway. No use of the Richview Corridor. With TTC, everything has to be on-street now.
But I think the transitway already is useful enough to connect to the airport. Also helps to connect Malton to the rest of Mississauga. Malton is not connected well to Mississauga, but at the same time the TTC doesn't serve Malton. So Malton is isolated from Mississauga, from Toronto, from Brampton, and that has resulted in many social and economic problems as you may know. Maybe this transitway will help fix this. It is a very important problem to fix.