Lol a 6 to 8 lane boulevard with massive backlogs seems like a nightmare.
It cant be high speed and would have to be pedestrian friendly meaning it be very bad at moving traffic.
Now if we make it with pedestrians bridges then it be good maybe.
Best option would be to tunnel it from cne to DVp with exit only at spadina York and jarvis.
That's the only real long term solution.
There is no justification for that east of Jarvis.
East of Jarvis the Gardiner doesn't really move all that many people.
West of Jarvis would require replacement capacity. That replacement need not be tunneled highway, though certainly some road capacity is part of the equation.