I appreciate the government's commitment, absolutely.
Your question about a threshold is an interesting one. I think it has less to do with the overall population of a community than it does with the way in which that community is designed. You can have a million people in an area that's spread out uniformly and would never support a subway, but you can have a million people concentrated along one corridor, like Yonge Street in Toronto, that could support two subways. Ultimately, it's a question of the distribution of those people and the way in which they're concentrated.
That gets me back to this whole issue of coordinating the development plans and the growth of a city with the transportation investment you make. If the plan is to develop a uniformly low- to medium-density set of residential, commercial, and industrial subdivisions, then you'll have to invest in a very extensive roadway and parking network that serves the local, the regional, and the high-speed connections with freeways.
If you build clusters of mixed-use medium- to high-density developments in places or along corridors where you can justify building light rail or a subway, and then decline that density as you move away, you can put in that kind of infrastructure. Those are the questions that need to be asked. What kind of future do we want? How do we want to develop our cities? Do we want to develop more automobile-dependent lower-density communities? Or do we want to put those million people around highly efficient and effective public transit?