Originally Posted by
agenkin
I don't trust Google Maps for cycling trails outside of the city. If it leads you on roads, it's usually fine, but what it designates as "bike trails" are often trouble.
It once lead me and a friend to an abandoned ATV trail running through a private hunting reserve. We found out we were trespassing and there were people with guns and hunting dogs around us.
Another time it lead a friend onto a trail that ended in a swamp. Google Maps thought that the trail continued.
It's highly unlikely that Google is surveying these sorts of ways. Who knows where or how Google gets the data for those. So, yes, you should be wary about the quality of Google maps in those places.
Openstreetmap (OSM) quality is variable but OSM allows people with interest in less popular features to add them to maps. That is, OSM maps might have better information about cycle paths/trails than Google does.