...or the simple solution of rumble strips. But that's way to cost effective for TorontoThe problem with most of the Hybrid options I've seen from non-technical people is they assume the expressway can make a sharp bend at the bottom of the Don Valley and right along the edge of the railway. The reason the Gardiner swings so far south, next to the channel, is because that's how much room it needs to make the curve at 80kmph.
There are a number of potential solutions. One is to make the curve a lot slower. That means slowing traffic down somehow (maybe even a traffic light or roundabout). .
Let me guess that they wills start the 50 zone at Jarvis and at Dundas. After all we need 2 km to make sure we are going slower! (which will make it more dangerous not less since it will be a ludicrous speed limit for 1.5 of the 2 km)