I'm trying to get all trails in the Middlesex Fells mapped using GPS tracks. I'm writing this down so that I can be consistent, and so that if I'm doing anything wrong, hopefully someone can correct me. This is a revision of a previous diary entry, after getting feedback, and more closely reading wiki pages.

The Fells has a bunch of trails whose main uses are (light) hiking and mountain biking. Near the reservoirs, there are areas that are off-limits to all users. There are also some offical-use-only access roads to various reservoir-related buildings and facilities.

So, first thing is that anything behind the "no trespassing" signs near the reservoirs gets "access=no".

Next, since the "highway" tag is documented as a "description of the importance of the highway for the road grid", and since the main uses of all the trails are hiking and mountain biking, the vast majority of them will be tagged as "highway=path".

The only exceptions to "highway=path" will be the access roads. The only motor vehicles allowed on these are official park vehicles, but they are otherwise open to hikers and bikers, except of course in the "access=no" areas.

These access roads are the only ways in the park with maintained surfaces. These will either get "highway=service" ("generally for access to a building") or "highway=track" ("gravel roads in the forest") depending on their condition and use. If not already "access=no", then they will also get "motorcar=no" and "motorcycle=no", because motorized vehicle use by the public is always forbidden (but might be otherwise implied by "service" or "track"). They will also get "tracktype" and "surface" tags, as appropriate.

Next, any way that is part of a signed, named trail will get "foot=designated". If it's also part of the "Mountain Bike Loop", it will get "bicycle=designated". Each of the named trails will have its own relation, and ways will get linked to them.

Finally, bicycles are allowed on any trail officially designated as a "Fire Road", so these ways will get "bicycle=yes". Anything not a fire road, and not on the "Mountain Bike Loop" is off-limits for bikes, and will get "bicycle=no".