I was working in the bush today and tested my Garmin Nuvi off-road. If you are on a track and drive off the road it says "Re-calculating" then it shows you driving on a blank screen; the directions in the headliner say "navigate to unpaved road" or to named highway if you are close to one. I was in an area of old overgrown roads and very new roads, the GPS gave me bad information for most of the day. I find it works well on main establihed roads and in towns/cities.

Mike