A method and apparatus for determining a lane identity of a vehicle travelling in a roadway where the roadway contains a plurality of lanes is determined based on information from sensors associated with the vehicle and map data for detecting the lane marker type to a left side and right side of the vehicle, any lane crossings during travel of the vehicle along the roadway, a history of lane marker type up to a predetermined travel distance along the roadway, and the lane marker type at the instantaneous position of the vehicle in the roadway. The lane identity method and apparatus outputs a confidence belief identifying the probability that the vehicle is traveling in one particular lane of the roadway.