In reply to neilinut:
The trouble with being completely separate from the road is that if the cycle lane is on the pavement the lemmings, sorry pedestrians, wander all over it in unpredictable ways, and when you get to a junction drivers pulling out don't look for you, and usually have right of way so you have to keep stopping. If the lane is on the road, but separated by a raised kerb then the street cleaners can't clean them and they get filled with rubbish and glass.