[Tagging] Underground power lines in tunnel

[Martin Koppenhöfer]

Am 05.06.2013 um 10:37 schrieb François Lacombe <francois.lacombe at telecom-bretagne.eu>:

> As you mentionned, the tunnel/bridge name can precise which bridge is
> but it's not a relational (or even spatial) way of bringing objets
> together.
> 
> Ok a tunnel isn't easy to map since we can't use GPS.


yes, but you can easily see whether it is one tube with both directions going through, or if there is one tube per direction (more usual case due to security reasons). Then you still have to define what is one "tunnel", maybe also 2 (or more) distinct tubes could qualify as one tunnel?


> But nothing
> prevent us to create a relation to setup such a link between roads and
> bridge for example.


Yes, you could either use a relation for the bridge (with name, ref, wikipedia and other tags, describing the bridge) and add the highways to the relation with a role running over the bridge, or draw distinct geometry for the bridge perimeter (and eventually geometry for the supports, pylons, etc.). The latter could also be done additionally and added to the relation). The same applies for tunnels besides that we often don't know exactly the shape of the tunnel.

cheers,
Martin