[Talk-GB] Maxspeed tagging for the UK

[Chris Hill]

On 09/04/11 08:20, Peter Miller wrote:
>
>
> On 9 April 2011 08:15, Peter Miller <peter.miller at itoworld.com 
> <mailto:peter.miller at itoworld.com>> wrote:
>
>
>
>     On 6 April 2011 16:53, Ed Loach <ed at loach.me.uk
>     <mailto:ed at loach.me.uk>> wrote:
>
>         Richard wrote:
>
>         > I'd put the number for cars (ie 70mph for a dual
>         carriageway), and
>         > the source if it's not the number that's on the sign.
>
>         This is similar to what I've done. For areas where a national
>         speed
>         limit applies I have used
>                maxspeed= (maximum speed for cars, which is the maximum
>         maximum I believe, if you see what I mean)
>         I was also tagging
>                maxspeed:type=national
>         or
>                maxspeed:type=national_dual_carriageway
>         (no others apply locally). I added these mainly for my use in case
>         the government ever change the maximum speed for cars on such
>         roads,
>         as has been rumoured on occasion in the press, so that I can use
>         XAPI or JOSM or similar to update the maxspeed values more
>         easily).
>
>
>     We seem to be nudging towards something close to a conclusion.
>
>     Can I suggest that the following two methods are valid, however
>     the second one should be considered to be 'better' and where it is
>     used then it should be retained to avoid edit warring.
>
>     I have worked a bit on the 'type' tagging to allow it to include
>     the county which might be GB or UK depending on how Northern
>     Ireland interprets the rules - is it always the same as the rest
>     of the UK?
>
>     On reflection the convention used elsewhere to put the IT:urban or
>     whatever into the source:maxspeed tag seems to be misunderstanding
>     the purpose of source tag which should be for such explanations as
>     'survey' or 'TfL open speed data' or whatever. Notice that I am
>     have used 'GB:urban' for the 30mph no sign situation to match up
>     better with 'IT:urban' etc.
>
>
> I have added some more examples for each method for clarity
>
>     Method 1
>     maxspeed=national
>     source:maxspeed=survey
>
>
> maxspeed=xx mph
> source:maxspeed=survey
>
>
>     Method 2
>     maxspeed=60 mph
>     maxspeed:type=GB:dual_carriageway (or GB:motorway, GB:rural, GB:urban)
>     source:maxspeed=survey
>
>
> maxspeed=70 mph
> maxspeed:type=GB:motorway
> source:maxspeed=survey
>
> maxspeed=60 mph
> maxspeed:type=GB:rural
> source:maxspeed=survey
>
> maxspeed=60 mph
> maxspeed:type=numeric sign
> source:maxspeed=survey
>
> maxspeed=30 mph
> maxspeed:type=GB:urban
> source:maxspeed=survey
>
> maxspeed=30 mph
> maxspeed:type=numeric sign
> source:maxspeed=survey
>
I *hate* the idea that signed speed limits that currently just need 
maxspeed=x would now need two extra tags. That is exactly what I meant 
by think of the mapper. Why should I add extra tags?

I have surveyed an area, added the road type, name, and a source tag, 
now to add a speed limit I need to double the number tags?!? This is ill 
conceived.

My suggestion:
maxspeed= x mph where it is signed.

maxspeed=national where NSL applies, with
national=single / dual to distinguish between single and dual 
carriageway limits. Motorways fall out automatically from the highway tag.

Please think of the mapper, and keep it simple. This will also be 
consistent with existing tagging / renderers etc and stands a chance of 
being used.

-- 
Cheers, Chris
user: chillly