Having drove and worked in central London many a time, all I can say is cyclists and motor cyclists there must have a death wish, especially in rush hour traffic. Weaving in and out of vehicles both stationery and moving takes balls of steel. Seen quite a few accidents as a result of impatience and stupidity from cyclists and drivers.
And there's the camera clicking tourists who think nothing of stepping into a busy road to take random photos of nothing in particular. Makes Manchester traffic seem like toy town in comparison. Got offered substantially more money to stay working in London, told them to keep it, too stressful.
Oh, I forgot to mention the overzealous traffic wardens that want to slap a ticket on your screen as soon as you try and park up.