The german city of Stuttgart is just doing this. Their entire downtown rail system
will go underground and create more space for offices, condos and parks.
Check this out:
http://www.spiegel.de/international/germany/0,1518,710388,00.html
That's awesome and seems like a better use of $5.4 billion than the Sheppard subway.
This time, I have a more elaborate megaproject: transform Spadina into a Champs Elysees-style boulevard from the lake to Bloor. Build a subway line with beautiful stations to replace the streetcars, widen the sidewalks to grander proportions with the finest trees, landscaping, stone paving, and public art. Consider also a landscaped median, have segregated bike lanes, and include Japanese-style automated underground bicycle parking silos. Demolish and replace all buildings along the boulevard lacking in historical and architectural significance and replace them with mid-rise modern buildings by the world's greatest architects but with conditions encouraging diverse materials, including natural stone cladding. At several major intersections, allow higher buildings.
Bury the Gardiner to restore vistas of Lake Ontario, and build a stone-paved roundabout at the Gardiner/Lakeshore intersection, with a massive vertical monument that would also be seen from the waterfront. A new park would go over the rail corridor at Spadina, but also buildings with retail. The Spadina south subway line would go to Billy Bishop airport, whose site would possibly already have become a part of the Harbour City megaproject built on Lake Ontario mentioned earlier. It could also then proceed to Centre Island or connect with an LRT line for the Islands. This LRT line would be built from the Port Lands as an eastern link. Ferry service could be retained as a way of linking the central waterfront with the Islands or possibly on an east/west axis of the Islands and new waterfront neighbourhoods: The Port Lands, the Islands, Harbour City in the west, and a mixed-use Ontario Place/CNE.
Finally, in terms of logistics and other megaprojects, it may be impractical to have Spadina become part of the downtown canal network due to its subway and road configuration, but it would intersect at least two east/west canals with grand bridges. The intersection at Bloor would be a monumental roundabout with another tall monument in the centre, which would make for a picturesque vista looking west on Bloor from downtown and east from west end neighbourhoods like the Annex. The name Spadina itself could be changed to reflect a famous Canadian or aspect of culture and mythology.
The great thing is that due to the compact nature of downtown, it's only 4.3 kilometres from Bloor to Queen's Quay according to Google Maps. If the subway was $1.5 billion per kilometre including all public realm improvements and the creation of monumental new plazas and roundabouts, the project would cost $6.45 billion. Add a fraction of a billion for the connection to the Islands and the LRT line on the Islands, and it would come to $7 billion. This project would also be the final nail in the Spadina Expressway's coffin.
