[OSM-newbies] Maxspeed

[Thomas Meller]

> On Tue, Mar 9, 2010 at 7:44 PM, Thomas Meller <thomas.meller at gmx.net>
> wrote:
> 
> > Adding a library function for everyone's use will improve lots of
> programs
> > and surely no-one will tag something explicitly if it isn't explicitly
> there
> > in reality - which will reduce errors, data size and mapping work.
> >
> >
> Ok, I see your point now. I'm not sure that we need another api for that.
> First, we need a good documentation on the wiki. Then one solution is to
> parse the wiki tables (there is an attempt for the maxspeed). Another one
> would be to identify the defaults inside the boundary with additional tags
> in the relation representing that boundary (e.g. in the  country or state
> administrative boundary relation, add a secondary:maxspeed=90, etc).
> 
> Pieren


I don't agree.

;-)

Take a way, found by any algorithm, find whether it is in some boundary object, sort the found boundary objects (ex: by admin_level), add all found tags - least admin_level-tag overwriting the former, and show the resulting set of tags to the application.

There are uses not restricted to using ways.

I climb rocks.
There might be the need to find a climbing facility for the next weekend.
I specify the difficulty level, the radius, the date and let software create a list of suggestions.

Near where I live, there is a rock inside of a game reserve. That is, you are not allowed to leave the ways from octobre til june. Resulting in 'climbing forbidden' til july.

Other example:
Road, find boundaries:
found :
- Boundary_Europe
- Boundary_Switzerland
- Boundary_Kanton_Solothurn
- Boundary_Communal_Grenchen
- Boundary_city_limit
- Boundary_landuse=residential

Road is highway=primary
Europe adds nothing
Switzerland adds maxspeed=80 kph
Solothurn adds nothing
Grenchen adds nothing
city_limit adds nothing (different in other countries)
landuse adds nothing
Road adds maxspeed=50 kph

Result: maxspeed=50kph
If the road wasn't tagged at all, the result would be maxspeed=80 kph.

Up to now, I cannot imagine every use of such functionality. It's extremely flexible and the mapper doesn't need to define begin or endpoint where tags apply. (virtual waypoints created dynamically at intersections of ways and boundaries)

Sort of cascading style sheet.
Up to now, OSM is simple-stitched work. Couple of points in a relation named 'highway', points or highways in different relations with different meanings (in every application interpreted individually), every object can bear name=value properties. Relation inside of relations inside of relations...
A good starting point...

;-)

Defining defaults and tidying them up surely will only work if it is clear which way to use them. Then it is an accompanying work which adds to quality.
But now, I think, we are far enough to switch to the developer's list.
It's getting technical.

-- 
http://www.openstreetmap.org/?lat=47.172&lon=7.4395&zoom=15&layers=B000FTFTT&mlat=47.16677&mlon=7.43513

Sicherer, schneller und einfacher. Die aktuellen Internet-Browser -
jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/chbrowser