I think this has been discussed here (somewhere) before, but I think the Leaside Spur Trail is still zoned in a way that it could be converted back to a transport corridor. You'd have about 140 homes (and one condo) that probably wouldn't be happy, but I wouldn't it be hard to justify a $1B tunnel here. IF Metrolinx someday decided to bring it back to get the more efficient route downtown, do they go surface level, trench, raised or tunnel? Or will it just not happen? My sibling's in-laws are one of those 140 homes.