| +/- access=designated
A way marked for a particular use.
If you are mapping Public Rights of way in the UK (specifically England and Wales) see UK public rights of way.
This tag indicates that a route has been specially designated (typically by a government) for use by a particular mode (or modes) of transport. The specific meaning varies according to jurisdiction. It may imply extra usage rights for the given mode of transport (i.e. normally a vehicle is banned, but in this case it is allowed), or may be just a suggested route (e.g. bicycles can in most jurisdictions ride on any street, but some particular streets are recommended and signed as such.) . To indicate an exclusive access see access=official, or just use access=no in addition to a mode-specific key (foot=designated, bicycle=designated, etc.)
Just as in other cases, if the designating sign implies restrictions on other modes of transport those restrictions should be tagged with their respective tags.
Note that access=designated is not defining what is designated and is meaningless.
Some places have designated snowmobile routes everywhere
The trail marked with the sign shown in the example picture (top right):
A UK bridleway:
A UK cycleway:
A UK footway:
A truck route in the USA: