3. The method of claim 2 , further comprising: determining (i) a first road corresponding to the longitude and latitude specified by the first positional data element and (ii) a second road corresponding to the longitude and latitude specified by the second positional data element; and correlating the first and second roads with mapping data to identify the first and second route links, the first route link being associated with the first road, and the second route link being associated with the second road.
4. The method of claim 3 , further comprising: determining whether the first road intersects the second road; and generating a portion of the routing graph that includes the first and second route links when the first and second roads intersect, the first and second route links being connected within the routing graph by a node.