[OSM-talk] Vertical ways (staircase)

[Lester Caine]

Ture Pålsson wrote:
> How should I map a staircase connecting a bridge to a street below? My
> initial thought was to approximate it with a vertical way with
> highway=steps, but is it even possible to have a vertical way? I.e,
> can you have two nodes at the same lat/lon but with different layers?
> (Do nodes even have layers?) Or should I try to map the actual
> zigzagging/spiralling of the steps? But that, too, leaves me with the
> question of how to map things that project on the same spot on the
> ground. Cheat completely and map it as a steep, but not vertical, way?
> 
> The route in [1] would be considerably shorter if the router "knew"
> that there are stairs between Norrbackagatan and the bridge.

Just as we are discussing how to get 2d shapes linked to ways, you come up with 
the perfect argument for 3d models ;)
There does need to be SOME level information in the tagging. The top end has to 
be on a level above the bottom, and the ways that are linking together obviously 
pass one another in different planes. A short diagonal way between the two will 
provide routing data, but while the ends may in practice be directly above on 
another, offsetting them in the area occupied by the steps gets around the 
editor limitations?

-- 
Lester Caine - G8HFL
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