It's a complete waste of money. There's absolutely nothing up there. I say this as a person who regularly drives to that neck of the woods and grew up in this area. The only stuff that IS up there is only accessible by car (imagine walking to Colossus to watch a movie from Jane and 7, or walking to Ikea even!).
As a person whose office overlooks the future terminus of the extension, I can say that there is more than "nothing up there". Do you think people drive up here because they want to view the scenery and be stuck in terrible traffic? Many people work in the area who live in Toronto and drive because the transit options are currently very limited, but can improve. The congestion is terrible, and it's pretty much all day. True, the area is currently auto-oriented, but that can change. I believe there will be a lot more buses coming feeding into the terminus, plus a ROW on 7. But why would anyone take the subway to go to Colossus? Regardless of the state of the pedestrian environment, it's still pretty far from Millway/7. Ikea will have shuttle buses.
Then there's the cost of it. I can't even imagine how much it's going to cost to tunnel under the 407.
Cost of tunneling under the 407 has already been determined and included in the overall cost. It is no different than tunneling under an empty field. The problem, that has been mentioned many times by others, is the fact that it will be tunneled in some places where cut-and-cover methods would be a lot more feasible.
Furthermore, not only is there nothing up there, there's a LOT of factories surrounding this area. Considering it's a major CN yard, those factories are not going anywhere soon because it's the optimal location for them. There's a LOT of better places to redevelop in Toronto before this area should be abandoned (all those old industrials west of Dufferin along the route of the subway extension for instance).
Downtown Toronto evolved from having major shipping yards along the waterfront. The CN yard is still a bit far away, but nonetheless the factories on either side of yard and along Creditstone can stay where they are for now. But other buildings along Jane can be redeveloped. Toromont is already leaving.
True there are some open fields that Vaughan is planning to make into the VCC, but there aren't even any solid plans yet, and so anything is at least 15-20 years down the road. Not only that, but even if all those empty fields were filled to the brim, there still wouldn't be that many people living there as I doubt Vaughan will opt for 50 story towers, but likely low-rise buildings instead. An even worse thing is that east of Jane is a giant creek, where you're not going to have any development on unless they pave over a creek, which I can't see happening. Beyond that are industrials right next to the CN yard.
Define "solid plans". Building permits, no, but there are a lot of plans in the works, such the Corporate Centre plans. Go tell the City of Vaughan Planning dept. that there are no plans and they will laugh you out the door. There are already approvals for 35-storey residential buildings at Creditstone so 50 storey buildings right at Jane is definitely plausible. There will be office buildings as well since the CC plans are for a major employment district as it's one of the Province's Urban Growth Centres, something that people always leave out in their arguments against the extension. Black Creek is not the Mississippi River. They could even engineer it be an open space area with walking trails and bike paths, or something like the Riverwalk in San Antonio.
Finally, there could be an argument about getting Woodbridge residents to use more transit instead of driving downtown, but then again, would those people really use the subway that much if there's no planned massive parking lot? Finch serves as a good place for Thornhill residents to get downtown because of the parking lot. Since Jane/Hwy 7 won't have a massive parking lot, Woodbridge residents with easy access to the 400 are much less likely to not drive and get dropped off there or take infrequent buses from their suburban locations.
For Woodbridge residents getting downtown, I think the proposed GO line to Bolton is ideal. If not, then improved bus service on 7 (such as the VIVA BRT ROW) can feed into the subway, or further east to a new potential GO station on Barrie Line, east of Keele. There's also going to be a 3,000+ space parking lot at Steeles West in the hydro corridor for those that want to drive to a subway station.
The extension is not just to get people downtown Toronto, but also for people who already commute north to Vaughan.
