[OSM-talk] The Return of the Highway tags and other junk

[Andy Allan]

On 12/18/06, Ben Robbins <ben_robbins_ at hotmail.com> wrote:
> They are phisical objects that have widths and lengths taht can varie.
> Therfore I would never tag them as a node, just as a building would be an
> area.

That's not going to work. Let's a gate is 2.65m wide, that's important
enough to be noted in the database, but the accuracy on each node
(from GPS, maps, imagery or wherever) is much less, There's no way you
can give the exact latitude and longitude of the right hand gatepost
and the left hand gatepost separately. So we mark the gate as a node,
and we can give the width as an atttribute. Moreover, if I come along,
realise you've got it in the wrong place, there's no way to tell that
you had the two nodes exactly 2.65m apart for a reason. Ditto cattle
grids, and buildings that are less than 50-100m in length.

> Well thats one of the points I'm debating.  The track contiues well beyong
> the permissivie footway.  So if i just tag the track, and asume it has some
> access right (wich I would like someone to state), then I cannot use this
> where its private.  Alternatively it doesnt state access in wich case
> footway is the higher.

There are certain properties for each of the highway tags that are
assumed by default. However, the defaults are poorly defined (if at
all) currently.

Please, if you have a track that is private, define it as highway =
track access=private, or any of the related access restrictions as
defined on the Map Features pages. You're unlikely to get any further
response when you keep complaining that highway = track has vague
access implications. It might well do, but you clarify and put
whatever restrictions you like - really, really easily - using
existing tags.

Hope this helps,
Andy