On 5 Sep 2009, at 9:15 , Steve Ratcliffe wrote:
Hi Mark
On 05/09/09 11:44, Mark Burton wrote:
Playing with my shiny new Nuvi 255, I notice that it can route across an OSM map of the UK pretty well. It can find long routes reasonably quickly. In comparison, mapsource 6.13.6 often fails to determine a route at all and when it does it is rather slow about it.
Previously someone claimed that on mapsource you needed a routable basemap to get good inter-tile routing, but that on a GPS device you don't. As the basemap is not sent to the device that makes sense.
Not sure about Mapsource. Roadmap for Mac has the basemap. But still routing doesn't work as good as on the Vista. Wild guess the Vista uses the basemap but Roadmap doesn't.
On the other hand the device may already have a routable base map and so perhaps it uses that if it has one and is the source of the observation.
I know that on my Legend Cx which does not have a UK base map I do not get very good routing across tiles.
does anyone know how to disable the basemap on a Vista? Another wild guess can it be that Garmin adjusts the basemap names/ boundary nodes .... with their map products on tile boundaries to help routing?
..Steve _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev