Samuel Dubose was shot after being pulled over for a missing front license plate. Sandra Bland died in jail after she was pulled over for not signaling a lane change. Walter Scott was shot while running away from an officer, after being pulled over for a broken taillight. These are all black motorists who were pulled over for minor infractions. The traffic stops lead to revenue for cities in the U.S., but they also increase the potential for hostile interactions between cops and citizens.