Its not they are all the worst drivers of the world, its that the city has undergone a mass influx of immigration over the last 25 years. You have every conceivable driving style from all over the world at once. You have no idea if the guy in front of your is an insane Brazillian sprinter, or an Iowa random lanechange grandma, or a New York lane grab/harsh braker, or a Texas 'five cars past the red' roadwarrior. The person driving next to you might be the best driver in the world; there is no way to consistently judge it. Its all frenetic and psychotic.