1. A method executed by a processor for forming a sensor bias measurement for a target moving on a road, the method comprising: obtaining by the processor, road location data from a database; obtaining by the processor, sensor observation data from a plurality of sensors; identifying by the processor, a sensor observation that corresponds to the target on the road to obtain an observation-to-road pairing; forming by the processor, a one-dimensional sensor bias measurement by calculating a perpendicular distance from an observation point to the road; and, storing and accumulating a plurality of the one-dimensional sensor bias measurements in a storage medium to form an estimated multi-dimensional sensor bias measurement.