A method and apparatus are provided for calculating potential paths through
a roadway network defined at least partially by separate, but adjacent
data maps. First and second data maps are provided that are indicative of
roadway networks for different geographic regions bounded by region edges,
at least one of which is common to both geographic regions. The data maps
are adjacent, and one data map contains the first location while the other
data map contains a roadway segment over which the potential paths may
travel. Potential paths are planned from the first location through the
first data map. When a current potential path intersects an edge of the
first data map, the intersection is identified by coordinate data. A
transition point is located in an adjacent data map based on the location
where the current potential path intersects the edge of the firs data map.
The calculation method and apparatus continue from the transition point
through the second data map toward the second location.
