[OSM-talk] Observed vs. official designation [was: Oxford High Street classification (Was: Bus sluice/gate)]

[David Earl]

On 01/12/2007 10:01, Gervase Markham wrote:
> But the open question is, should 
> highway tags be defined for the benefit of routing algorithms and/or map 
> rendering (one possible view) or should they be defined according to 
> legal classifications, and additional auxiliary clarification tags used 
> in the occasional situation where the legal classification would mislead 
> rendering/routing software.
> 
> Granted, I'm new to OSM, but I'd argue for the latter.

I disagree.

(1) It is singularly unhelpful for a user of a map to find that the 
situation on the ground is different from what the map says. It is 
unlikely OSM would find its primary market in officialdom where such 
distinctions do matter.

(2) It is very hard to get the "official" information. Most of us only 
have what we see in front of us to work from. It is impractical.

(3) The vast amount of data already there is tagged by observation. 
While no doubt we could change a certain amount automatically, there 
would always be loose ends - especially for the cases affected by the 
reason the change was being made. And even having changed, some people 
will continue to tag things the way they want rather than following a 
consensus (though that already applies the other way round too).

Having said that, I see no problem in having some additional information 
which gives the "official" designation if different. For example - 
"ref:official=A120" or "highway:official=primary".

David