A navigation system for use in a vehicle (402). The system includes an absolute position sensor, such as GPS, in addition to one or more additional sensors, such as a camera, laser scanner, or radar. The system further comprises a digital map or database that includes records for at least some of the vehicle's surrounding objects (400). These records can include relative positional attributes with respect to a reference axis (404). As the vehicle (402) moves, sensors sense the presence of at least some of these objects (400), and measure the vehicle's relative position to those objects. This information is used to determine the vehicle's instantaneous lateral offset (428) relative to the reference axis (404), and support features such as enhanced driving directions, collision avoidance, or automatic assisted driving. The system also allows new objects (408, 414) to be attributed using relative positioning, and thereby factored into the enhanced navigation features.