Roughly a dozen dirt bike riders on Wednesday snarled traffic on southbound Highway 101 in San Francisco, before some were caught on camera punching and kicking a Toyota Camry driver, who tried to drive around them, but instead ended up with a broken leg.A man's leg was broken when he was punched and kicked by roughly a dozen dirt bike riders, who snarled traffic by doing wheelies and stunts on southbound Highway 101 in San Francisco Wednesday, before assaulting him.Read more www.nbcbayarea.com/news/local/Roughly-a-Dozen-Dirt-Bike-Ride