Whereas I like the theory of safe cycle lanes (although I am not able to use them), the whole thing in most towns and cities has been badly managed. Cycle lanes should be quite separate from roads, not just the inside (nearest to kerb area), coned off for them. It is almost impossible to make such alterations in our already far too busy town streets without virtually starting from scratch. The London borough in which I used to live, narrowed extremely busy roads, but just making a cycle lane along the edge. This has resulted in so much traffic congestion along the main roads, that air quality has got very much worse.
To start with, it needs a really excellent and reliable and economic public transport system. This would encourage people not to use their cars. Of course, vans for tradesmen, and lorries for deliveries are still going to need roads, as will buses. Because of the cycle lane, narrowing the main roads so much, the buses are not able to keep to any sort of proper timetable - so people trying to use these to get to and from work have been unable to do so - so back into their cars!!!
In any case, it is not healthy for cyclists to have to go along the side of those vans, lorries and buses. They need totally separate areas.
I do think bus lanes have a place - to permit this sort of public transport to proceed quickly and easily. I find it strange how in some places these bus lanes seem to start and stop as no road widening has taken place, or else the road has actually been narrowed with the cycle lanes.