We need a lot of training of motorists and cyclists in this country. I was in London at the evening peak (at the front of a routemaster!) and the number of cyclists going straight through red lights, across pavements, blindly cycling out between gaps across the road without looking... and also the amount of motorists disobeying Advance Stop Lines, and compulsory cycle lanes...
Police officers need to be employed to have a crackdown on this. And once they're done they can work on people who hold tube train doors open!
Don't even mention London. Go on a cycle forum and you'll get many cyclists claiming it's only a minority of people that break the law. In London (central London at least), it's probably 90% or more and that's NOT an exaggeration. Only the minority will abide by the law, and they get hassle from other cyclists and probably end up joining in eventually.
People hiring Boris Bikes are obviously terrible too - ignoring the 'instructions' given on what you can, and can't, do. Long gone are the days when it was just bicycle couriers that broke all the rules. All they did was set the benchmark for everyone else!
FWIW, the police do sometimes stop people and issue on the spot penalties, often in the City of London, but it's rare and cyclists can probably see them and become like a motorist - become model citizens for a short time.
What's worrying, however, is how many don't comply when they see police and get stopped and then it becomes clear they didn't even know what they couldn't do. After all, anyone can cycle and there's no training required. A lot of cyclists argue that it's safer to jump lights as it can give them a clear route (sod pedestrians).
Pathetically designed cycle paths must contribute to this growing problem, as they 'force' cyclists back onto roads and in the end, they just look for the shortest route which means crossing pavements, up the wrong way on a one way street and taking all sorts of risks. Go abroad where cycle lanes are done properly and it's totally different (The Netherlands excepted; they're just as bad and the Government designs roads to give them priority over everything!).