[OSM-talk] Changed highway=*_link meaning?!

John Smith deltafoxtrot256 at gmail.com
Fri Jun 25 07:30:36 BST 2010

On 25 June 2010 16:10, Ed Avis <eda at waniasset.com> wrote:
> I think you misunderstand my proposal.  I agree that is_in is redundant and
> should not be added to the map.  As you say, it can be derived from admin
> boundaries.  However, not every programmer might want to have to download all
> the admin boundaries and work out what is in what.  Conceivably, it might help
> some applications if there were an option for the server to automatically add
> is_in tags, generated from admin boundaries, when some map XML is downloaded.
> That way the code to work it out only has to be written once.

You are talking about pre-processing, that is taking the data and
manipulating it and then doing something in another app with it, and
this isn't something that has to be done with OSM directly, or even at

> A road could appear as a dead end because of bad mapping - but then anything else
> on the map could also be bad mapping rather than reality.  Anyway it's just an
> example.

I doubt you can make an assumption of a dead end, it might be a
mapping mistake, or a way that hasn't been surveyed completely.

> True, but if a way is tagged highway=steps or slope=yes, it's a pretty safe bet
> that going from layer 0 to 1 is uphill, and 1 to 0 is downhill.  Even though in
> theory there is nothing to guarantee that.  (And if elevation is tagged, uphill
> and downhill markers can be deduced for certain.)

Most layer tags apply to bridges, not to steps because they don't go
over the top of anything else.

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