Abstract: A method of determining a correspondence between first and second digital maps is disclosed. Each map comprises a plurality of arcs connected by nodes representing the road network in a geographic area. A line location representing a route with respect to the first digital map for which a correspondence is required with respect to the second digital map is input to a correspondence module. The module uses map linkage data to determine corresponding location data with respect to the second digital map for use in providing a vehicle horizon. The map linkage data comprises data indicative of a plurality of arc sections of the first digital map, and, for each arc section of the first digital map, data indicative of a corresponding arc section of the second digital map. The map linkage data enables, for a starting arc section in either one of the first and second digital maps, a corresponding arc section in the other one of the first and second digital maps to be obtained.

Abstract: Disclosed herein is a technique for processing map change data in a map client that uses the map changes to apply changes and updates to current map data. The map client provides the updated map data to other components in an autonomous vehicle. The map change data describes the processing in the map client to obtain updated map data from the map data.

Abstract: Disclosed herein is a technique for generating and providing an indication to an autonomous vehicle regarding the confidence level for the accuracy or quality of the map data in which the indication is determined from observation data received from other vehicles.