All calculations are based on an intelligent, multi-layer routing algorithm. For very long routes, the system may rely on a supra-layer that only includes motorways or major roads for route calculation. Map files are compiled in a way that the country tiles can be arranged according to available storage space. This allows seamless navigation across country borders and map tiles. For a wrong turn or at deviations, the routing algorithm performs an instant re-routing. Due to a distance-based background routing algorithm the re-routing doesn’t take longer than a fraction of a second. The routing algorithm defines an area around the current car position and calculates all possible routes that lead to the destination inside this area. If the car moves along the route and approaches the border of the defined area, a new area with all possible routes is calculated in the background. If the car leaves the route, a new route is immediately available, because one of the pre-calculated routes can be taken from the defined area. A new area with all possible routes is calculated in the background. This way, the navigation software can immediately provide a new route with minimal calculation time.
As the car moves, a bounding rectangle is constantly updated to cover the area from the current position to the destination. This bounding rectangle can be used to create a view that shows the driver the route from the current position to the destination. For example, you can have a split screen, with maneuver arrows on the first screen and a route overview given by the bounding rectangle on the second screen. Parts of the route can be excluded from the route calculation. This feature is particularly useful for detours or closed roads. Excluded parts can be defined by specifying a bounding rectangle (all roads inside the rectangle are blocked) or by selecting a route segment. For time-restricted roads, the navigation provides a horizon-based