but I think all the access tags you’re looking for are in use and documented on the access key wiki page. Access tags for the examples you mentioned are:
- Motorcycles -
motorcycle=yes/no
- <50 inch off road vehicles -
atv=yes/no
- 4WD vehicles only
[4wd_only=yes](https://wiki.openstreetmap.org/wiki/Key:4wd_only)
besides the 4wd tag these are legal access tags, right? (excuse my ignorance, but neither 4wd nor atv are vehicle classes in my area). If it would be legal but physically impossibile or dangerous to use such vehicles, the value would be “yes”?
(I checked the wiki and 4wd_only is not a restriction but a recommendation)