Raise the Hammer

If what you're suggesting is that we pare Main down to three* (or even four) lanes, make some real sidewalks appropriately scaled for an urban thoroughfare, put in a two-way protected bike lane, and add some trees: I could be content with that. It would make Main a hospitable street for all users, and a more pleasant street for residents and businesses nearby. (There is still a lot of evidence that one way streets are far less safe for pedestrians.)

*Three lanes on Main east would result in each lane carrying about the same amount of traffic now carried by Garth and Upper James lanes, assuming traffic volume remains constant (but it has been dropping on Main, and would probably drop further if the road were narrowed). That would be a much more "space efficient" use of that real estate, quite adequate for the car users but also making a lot more space for other users. And the other users would enhance local commerce a lot more than through drivers do, so it would also be an economic boon. Why don't we do it tomorrow?

Now, as for your suggestion (in the next comment) to lower the speed limit, first, I think the speed limit should certainly be lowered. 50 km posted speed gets you 60 km driving, and that's way too fast in so dense an area. But second, the main determinant of how fast drivers go is not the posted speed limit but the "feel" of the road. That's how speed traps work: the road "feels" like a highway, but is posted for a slower speed. Main feels like a highway, and its current configuration, five lanes of one way traffic and relatively few cars compared to the amount of available space, certainly adds to the speedway feel. If you added trees, a protected bike lane, wider sidewalks, you could go a long way to changing the feel of the road. But some such steps would, I think, have to complement lower speed limits, if the lower speed limits are to be effective.