Something that infuriates motorists, understandably, is when they see cycle facilities that aren't being used. (Freewheeler recently brought a pertinent example to our attention in his home territory of Waltham Forest.)
Here's one in Liverpool Grove, just off Walworth Road in south London. In the ten years I've been around here, I've never seen a single cyclist using this bike lane. It clearly can't be the fault of the parked car - that's in a marked bay, placed quite legally. Use it or lose it, guys!