A map server receives geographic points from a location tracking device located in a vehicle. The received geographic points describe a path that is representative of a pathway of the vehicle used to complete a trip from a starting location to a destination location. The map server identifies candidate geographic points for each received geographic point where each candidate geographic point is associated with a location on a known roadway. The map server determines a graph of the candidate geographic points and identifies different sub-graphs from the graph. The map server iteratively evaluates the sub-graphs to determine a shortest path from the starting location to the destination location without evaluating all the edges in the sub-graphs.