Most of our current infrastructure (highways, subway, raillines, ports, etc.) were built prior to the 1970's and we had no deficit, lower unemployment, better standard of living etc. Have all the costs and delays associated with the EA process really helped us?
I think the difference is a few things:
1) Environmental concerns: Not necessarily EAs, but the level of consciousness that environmental issues have today. Let's face it, if the DVP were on the books today, there would be conservation agencies and environmentally conscious members of the general public doing everything they could to stop that project. There wouldn't be a hope in hell that that project could get built today.
2) Lack of (or willfully ignoring) public consultation: In the 1950s especially, expressways were ripped through inner city neighbourhoods like they were nothing. This wasn't so much the case in Toronto (the DVP was built largely in a river valley and the Gardiner on old railway and industrial land), but many American cities faced this.
The Spadina Expressway really marked the beginning of the public actually having enough of a voice to stop a project. This is also part of the reason why no new expressways have been built in Toronto since then.
3) Labour and construction costs: Cheaper to build (even when adjusted for inflation), and the governments had more money to spend on infrastructure, so more got built.
I think that the drawn out EA process is symptomatic of a different problem in the planning and construction world, especially when dealing with government projects: lack of confidence. I don't mean like "we suck" lack of confidence, but lack of confidence in the political powers to see things through to the end.
The process for public infrastructure projects doesn't have nearly as much timeline overlap in it as private projects do. Why? Because with private projects, unless some disastrous scenario comes to light, the people doing the design work know that it's going to be seen through to the end. With public projects, there's this cloud hanging over the entire project, the feeling that some crackpot politician can come in at nearly any time and pull the funding for the project. This leads to a much greater CYA (cover your ass) approach to the project, and much less overlap. You don't want to start on detailed designs until the funding is 100% secure (and even then it's no guarantee you'll finish final designs).
I think that if there was more stability in terms of the future of public infrastructure projects (not being cancelled on a whim), then more overlap in the process could potentially shorten the design timelines and get shovels in the ground faster.