Why do we need to slow down and even stop cars if we in your proposal even have a dedicated bike lane? Why not put up a small barrier between cars and bikes and have everyone go their own way? Speed limits on the US already are insanely slow compared to most of Europe and the bike thing seems to work better their regardless. We need more diverse infrastructure for different modes of transportation. I want trains that go 200mp/h, dedicated bike routes, and smaller dedicated roads for cars that are better organized with much higher speed limits and walkable city centers where pedestrians can feel safe from cars AND bicyclists. Sounds crazy but works in parts of Europe.

As a cyclist I've seen too many barriered-off cycle lanes that left me trapped and unable to go where I wanted to go, so if my choice is the main road or a cycle lane behind a barrier, I'll stick to the road. Separate lanes make sense for between-city highways, but inside the town speeds are already low enough - and space limited - that we ought to be able to share.