[Talk-GB] maxspeed changes
Philip Barnes
phil at trigpoint.me.uk
Tue Sep 25 09:01:00 BST 2012
I can think of quite a few border roads that will need signposts before that happens.
Phil
--
Sent from my Nokia N9
On 25/09/2012 1:38 SomeoneElse wrote:
Peter Miller wrote:
>
> Correct. I did however use alternative maxspeed:type at times which
> also appears in the DB and which I feel is better than source:maxspeed
> which to my mind should be used for 'source:maxspeed=survey' or
> 'source:maxspeed=local authority spreadsheet-Dec12' or similar.
> However... lets leave that discussion to another day but either way
> not information has been lost by my edits and the data has been made
> more consistent.
>
The problem with e.g. "source:maxspeed = uk:nsl_single" is exactly as
you describe it - it doesn't actually describe the source of the
maxspeed, merely its type. For example, in this case:
http://www.openstreetmap.org/browse/way/135256609/history
"source:maxspeed = sign at E" would be correct, rather than as currently
tagged. If I want to add that bit of information, I now can't.
In terms of UK maxspeed tagging, according to taginfo there are around
10k UK "source:maxspeed=UK:nsl_single" or similar values, and around 5k
instances of "maxspeed:type" - both relatively large numbers. The
largest number of "source:maxspeed" is still "sign".
Presumably the argument for tagging "maxspeed=60mph" where it's actually
signed as "national" is that it's too hard for routers to figure out
whether something's a single or dual carriageway? I'm not sure why we
have to depart from the "on-the-ground" rule in this case - if it's not
obvious that something's a dual carriageway surely that's a tag that
should be added, not some curious code value stored against a tag
(source:maxspeed) that's usually used for something else entirely?
With that in mind, I don't personally see a problem with "national" -
After all, there are certainly plenty of other speed limits that aren't
a nice number - UK motorways with active traffic management, French
motorways when it's raining, and (according to the wiki) German iving
streets.
The other issue, of course, is how long "UK:nsl_single" (or
GB:nsl_single, which is also used) will continue to be meaningful; it
wouldn't surprise me to see different "national" single carriageway
limits in Scotland or Wales within 3-5 years.
Cheers,
Andy
_______________________________________________
Talk-GB mailing list
Talk-GB at openstreetmap.org
http://www.openstreetmap.org/browse/way/135256609/history
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-gb/attachments/20120925/5dcb7737/attachment.html>
More information about the Talk-GB
mailing list