Segregation is very common place here in my little corner of Northern Germany and it works really well. A lot of our cycle paths are actually just designated sections of the pavement. We also have a lot of cyclist only traffic lights dictating our movements. The cycle paths themselves are often marked out by a different style of brick or paving slab, so no slippery paint to negotiate or maintain.
One of the reasons it all works so well here is that we have a very strict law on presumed responsibility, so if a bike hits a pedestrian then you are presumed at fault, likewise if a car hits a bike. Also bikes and pedestrians can cross side roads without stopping. Anything going into a side road must give way to any thing crossing it. We also have a very active Police force here who will ticket and fine you on the spot for transgressions. They even have the power to endorse drivers licences if the offence is big enough.
Another key fact that helps is that we have reached critical mass where by every one cycles, so there is no need for education, because we are all participants.
Until Britain becomes more enlightened, starts to change the law and realises that there is no us and them with any other road/pavement user and gets more folk cycling, then no amount of good infrastructure will fully work.