I’m not sure if my problem has been a topic here, searching the forum didn’t give me an answer.
I used “ready made” OSM maps of germany from different makers on my Zumo550 for many years with great success.
Now I let build a map on http://garmin.openstreetmap.nl (Generic Routable (new style)), containing germany/austria/switzerland, put it on the SD card and have two strange behaviours:
(the original Garmin map (City Navigator Europe NT 2008) resides in the internal memory, but is switched off).
I made a route from Hamburg to Weimar (containing only start and destination points, option fast) and it goes a long way via Berlin which is definitely neither the fastest nor the shortest route.
I added a third point on the Autobahn (of course on the south going lane) near Hannover which made the route nearly 50% shorter and faster. But now there are parts of the route consisting of strait lines going right beside the roads.
I checked some other routes and this behaviour (route is leaving the road) occurs again.
Does anybody have an idea, what might be the reason?
Thank you in advance an regards