[PaulHoule]

Some satnavs will let you pull on the route to change it.

We have a running gag about the bad roads in Upstate NY; frequently you see a road on a map that looks passable, but if you try it you may find four-foot potholes. The old USGS maps are often wrong and may not have been corrected if tree cover is sufficient you can't see the road from the sky.

My late-model Garmin is conservative about what roads it takes, avoiding many good roads, but last week I saw some lady get stuck in an unplowed road in the state forest that her GPS sent her down despite a sign that says the road is unmaintained from Dec 1 to Apr 1.