I don't know what you're trying to say here... As far as I care, we can just ban cars entirely, but until then, separating the multi-ton metal boxes traveling at over 100 km/h operated by barely qualified teenagers from the squishy cyclists and pedestrians seems like a pretty obvious solution.
If roads are for cars, then you will have no problems with abolishing people being inside of them while they drive on your sacred car only roads?
> Add more walking and cycling paths and bikes/pedestrians won't have to use the roads.
Add them where? Because in your scenario it's either cars or pedestrians and guess who have better lobbyists?