The invention provides a method of resolving a location in a second digital map from an ordered list of location reference points determined from a first digital map. The method involves identifying candidate lines and nodes in the second digital map, and using curvature, height and gradient information associated with the location reference points to identify the most likely candidate nodes or lines in the second digital map corresponding to the nodes represented by the location reference points and to lines emanating from or incident at the node in the first digital map. The method involves carrying out a route search between the most likely identified candidate node or line identified for one location reference point, and the corresponding node or line associated with the next reference point in the list, and repeating this step for consecutive pairs of reference points until the final location reference point is reached.