I know I've said it before, but in the light of current events, I feel like I can't stress it enough: If you can't drive your bike faster than a pedestrian walks, then GET THE F*** OFF THAT BIKE AND GO BY FOOT! There should be an official minimum speed for bikes on the road, and parents with children shouldn't be allowed there at all until the little ones learn that driving alongside big, heavy cars isn't a game.
And for those that can't go any faster because they're sooo old: If you're old enough to be at risk of a heart attack at any moment, what are you doing on a bike in high traffic anyway? You might cause an accident and get not only yourself killed, but a couple of other people as well! If you don't want to walk, there's still busses and trams and the underground for you.
People have already said about me that I must have been absent when "God" distributed tolerance, but at least I was present when he handed out brains.