In a country where they went from virtually no cars to more cars and bikes than the road infrastructure can handle, it happened so fast that they never really incorporated a general driving protocol.
So while a cop will stop you if a motorcycle 'driver' is not wearing a helmet, it's ok to have 4 on a bike with no one else wearing one; in fact it is common place to see an entire family -- father, mother and several kids -- all jammed on a scooter.
Weaving in and out of traffic doesn't get a second look either, nor does speeding: I've buzzed by many a motorcycle cop without them caring.
There are really only rules when driving a motorcycle here: don't get caught without a helmet, and try your best not to get killed by a driver doing something stupid, and stupid drivers doing stupid things are everywhere. What do I consider stupid? Stopping in the middle of a four lane road because the driver sees a friend and wants to chat; diagonally crossing the road while driving against traffic; making a K turn in the middle of a busy intersection, for example. Its semi-organized chaos driving here, which I why I love it so -- after all, crazy is right in my comfort zone.
I spoke about driving in Bangalore before, but now having been here for two years I've come to understand the flow of madness a little better. The trick is to never stop: you have to move and merge. If you come to a corner and stop, finding an opening to get going again is a huge task, Instead, you slow down as you approach an intersection, assess the spacing and speed of those in the cross road and just merge in.
There is basically no 'right of way' rules here, so as you're traveling a main thoroughfare you can't assume an approaching vehicle on a side-road will stop; if they feel they are going to hit the intersection first they'll just keep going.
Secondly, you have to always be alert on city and country roads alike for oncoming vehicles, especially buses; they will come head-on at you in YOUR LANE as though they have a right to be there. Rickshaws and motorcycles will cut across in the wrong direction WITH THEIR LIGHTS OFF! Suddenly you feel the wind of someone who just cut in front of you and realize it was vehicle you never saw.
Welcome to driving in Bangalore, India