Back in London I'd be distressed - horns there generally mean anger or imminent collision. Here it feels more that they are simply a way of gently nudging your fellow road users. Nobody follows the rules much, there's no lane discipline, yet curiously no visible anger or discourtesy, no audible screeching of brakes, and the bikes keep weaving through the road with their one, two, three or even four helmet-less passengers chatting away cheerfully.
It seems to me that it's a kind of non-aggressive anarchy. You don't follow the written rules much, but you have a lot of respect for the unwritten ones, of keeping people alive and property undamaged and tempers cool.
I wonder if Gandhi ever talked about the traffic?