Cycle campaigning

I remember a group (can't remember who) suggested complete separation for some roads, ie where some roads are in a grid pattern, such as zone 1, have the whole road closed to cars and signage point cyclists to their specific road. That idea did sound kind of appealing but seems to have gone quiet so must have run into trouble.

Some of the London Cycle Network is almost like that minus the closure to motorised traffic.

They use smaller road that run parallel to says, CS7 while it take probably between 5 to 10 more minutes to cycle, is a lots quieter, easier and comfortable to ride on, especially when some road are a dead-end consisted of bollard on the middle of the road enabling only cycle traffic through.