[talk-au] 4wd_only

[John Smith]

While it's not my proposal I updated it to match the current aussie guidelines. Please vote for it if you are in favour of this tag so we can get 4WD Only tacked on the end of road ways.

http://wiki.openstreetmap.org/wiki/Proposed_features/4WD_Only

Australian Tagging Guidelines, based on talk-au threads.

http://wiki.openstreetmap.org/wiki/Australian_Tagging_Guidelines#4WD_only_track