On Feb 19, 2009, at 11:57, Clinton Gladstone wrote:
I appears to work fairly well in mapsource although I have found that for long routes it gives up and draws a straight line even though it can route OK if you add some intervening waypoints.
I can also confirm this behaviour: in a test crossing multiple tiles over a long distance (from Heilbronn to Cologne), Mapsource attempted several recalculations and then drew a straight line from start to destination. When I added an additional point to the route, Mapsource immediately recalculated the route correctly.
If you shift this additional point towards the destination, is there a specific point where it starts going wrong? One possibility is that the routes are just getting too long. I remember somebody saying there's a limit on the number of legs when routing using Garmin units. This might be fixed by writing so-called links (shortcuts in the routing graph), which we're not doing at all at the moment. Unfortunately, they're less well understood. If there's a problem routing from Heilbronn to Cologne, it'd be interesting to see if that also shows up within a single tile. Say, a tile with all of Heilbronn and Cologne, but only motorways in between. Cheers Robert