Painted bicycle lanes are actually dangerous in my opinion. I cycle almost every day in London for now about 6 years. I avoid streets with painted cycle paths if I can (and take parallel side roads instead). The way I see it, painted cycle lanes makes cyclists feel secure, but does not create much awareness by motorists. They are mainly used on roads with a lot of traffic. Because they are painted they have sometimes…
If I want to cycle fairly briskly - say 15MPH - that can't be done on cycle lanes that share a pavement. It can be done on the road.