[OSM-talk] Turn restriction docs

[David Earl]

On Sunday 30 November 2008 03:07:02 Ulf Lamping wrote:
> I've just added a table to that wiki page that tries to map existing
> road signs to the corresponding restriction values.

In most situations where you see these signs they are used in 
conjunction with a No Entry at the end of a one way street (or in the 
case of 5 and 6 when you are joining such a street). So long as the 
street is tagged oneway then a turn restriction as well seems overkill, 
as all traffic is prohibited from entering. It's not wrong, but it 
doesn't add anything. Presumably the only cases we're really interested 
in are those where traffic from one direction can't do something that 
traffic from another direction can.

Incidentally, there is a set of pictures of UK traffic signs and their 
meanings in the Highway Code, at 
http://www.direct.gov.uk/en/TravelAndTransport/Highwaycode/Signsandmarkings/index.htm

(There is also a very precise definition of every sign and its permitted 
configuration elsewhere on the net, but that's overkill for these purposes).

David