[Talk-GB] Speed limits on private roads - maxspeed:advisory or maxspeed?

[Robert Skedgell]

We have quite a lot of private roads signed as and tagged with maxspeed
values below 20 mph, however the wiki description for maxspeed includes
"maximum legal speed limit".

Many speed limits on private roads should probably be tagged with
maxspeed:advisory, unless there is both:
1) a traffic order setting the speed limit
and
2) an authorised speed limit sign, either GB:670 or GB:674 (20 mph zones
only).

DfT Circular 01/2013 also states that "Any speed limits below 30 mph,
other than 20 mph limits or 20 mph zones, require individual consent
from the Secretary of State."
https://www.gov.uk/government/publications/setting-local-speed-limits/setting-local-speed-limits

An example local to me, which I have tagged as maxspeed:advisory=5 mph.
There is no traffic order and the sign is not GB:670. The legal and
enforceable speed limit is probably GB:nsl_restricted, i.e. 30 mph.
https://www.openstreetmap.org/way/707266569
https://westnordost.de/p/27324.jpg

-- 
Robert Skedgell (rskedgell)