[OSM-talk] Routing on OSM maps on a Garmin device

[Maarten Deen]

I have a Garmin Nüvi 205 which I normally load with an OSM map if I go to
Germany. The standard map on the device is NL-BE-FR with bordersections of
DE. Usually I get the tiles I need from Lambertus, but yesterday I took the
basemap for germany from All_in_one_Garmin_Map.
While I was at the far point of my trip and wanted to go home (about 275
km), my Garmin was unable to calculate a route. It came up to 99% and then
failed. This also happened in the morning on the way to the first waypoint:
the Garmin made a dumb routing choice (for the locals: A40 Dutch border to
A4 Engelskirchen via A57 and the center of Cologne) and I drove the route
that I knew was best, and as soon as the device noticed that I didn't take
the route it calculated, it calculated again and failed. A route of just
100 km.

In both cases, as I got closer, the route could be calculated.

The Garmin has 3 routing modes: fastest, shortest and most economic route.
I normally have it on fastest route, but when I put it on most economic
route for the way back, it did calculate a route (and wanted to get me off
the motorway at every turn), while it still did not want to route me on
fastest route (that was between Soest and Dortmund).

Does anyone have similar experiences, and maybe an explanation why this
happenes? Are the OSM maps too detailed for a simple device like this to
calculate?
Cloudmade calculates both routes as expected, so I would exclude data
error (e.g. non-connected roads) from the problem.

Regards,
Maarten