My experience of commuting by bike across London for five years is that the real problem is not that other road users don’t see cyclists - they see them perfectly well, but they see them with only their eyes, they don’t see them with their brains.
They’re looking only for things - basically motorised traffic - that can harm them; consequently they don’t take the appropriate avoiding action with regard to cyclists.
I lost count of the number of times pedestrians looked me straight in my eyes, paused, and then stepped off the kerb right in front of me (and in broad daylight). Invariably there was either no motorised traffic behind me or none close enough to warrant the pedestrian waiting. I read only last week (in Cycling Weekly was it?) of an accident involving someone moving into the path of an oncoming rider; it was “Sorry mate, I was looking for cars”!
All the “safety for cyclists” infrastructure and paraphernalia in the world, short of totally segregating bikes from other traffic (which I’m not arguing for) won’t make a blind bit of difference until drivers are properly penalised for careless driving. That means either severe financial penalties or banging ‘em up for a few months. Not just trivial fines and a few points on the licence. A few instances of “Christ, did you hear about [Tom, Dick, Harry] - he hit a cyclist and he’s in clink, lost his job, can’t pay his mortgage and his wife’s’ on the street” and people will soon start paying attention. Basically, just like they do if someone’s hammered for getting caught causing injury whilst driving without insurance.
Ooooh, sorry ............. went off on a Daily Mail rant there !