The big issue is at St Clair, as it will be impossible to make a right hand turn from a road that is at 45%+ for tucks and buses. Even for cars, you still need a large turning area and not enough room to allow for it. Also, the westbound platform will be in the way.
Even the plan widening of the overpass will not resolve issues for turning right.
Having 2 intersection so close to each other will have an impact on traffic flow.
Trucks would have to use the Gunns connection only. This is the best option than try to take the road south of there to Davenport. If you want to take it to Davenport, needs to be a raise overpass with no connection to St Clair.
The old Hepburn Lands now the Bingo Hall and the old Cadets land will provide room for the extension, but will have to tear down at least 10 houses and no great lost based on condition.
Doing this will increase traffic more on Davenport and its bad now without trying to add bike lane. Bike lanes will require the removal of on street park and no great lost.
Also, how do you deal with Union & Townsley connection as they would be come dead end streets with this extension. As for Turnberry, it will see increase in traffic if extended to Gunns for people who use Rogers Rd route.
With the Gunns connection, TTC would remove the current northbound route for 41 and that service will be replace by other service and shorten travel time. 41 south would move from Weston Rd and have a shorter route and runtime.
https://maps.google.ca/maps?oe=utf-...=ca&ei=vMmYUtWuKNDzoATZqYGACA&ved=0CC0Q8gEwAA