[OSM-talk] line length; checks in server

[Nicola Ranaldo]

> > forbid segement from a to b, if exists a segment from b to a ?
>
> But only if it has the same tags. Think of:
>  - Two streets above each other. One on each level of a multilevel Bridge.
>    I've seen quite some of those
>  - A footpath under a bridge of a highway
>  - A shopping center/car park/... with multiple lanes on top
>    each other in differnent floors.

the highway may have a segment from a to b and the underlying footpath may 
have the same lat/lon segment from c to d, two different nodes with the same 
lat/lon and different elevations?

howewer if a segment from a to b exists should we avoid  a "logical" 
duplicated segment from b to a (note.. not from a to b)?
This introduces a problem with oneway segments.
You may have a to b oneway and b to a with no restrictions and so on.

> > Actual scheme will suggest this, but i think you have to choose and
> > formalize a robust solution becouse two nodes with the same
> > lat/lon/elevations let users create unconnected paths. If we adopt the
> > duplicated schema all editors should warn users of these nodes while
> > selecting them.
>
> Warn - maybe, but still allow them. I'm just thinking of Boat lifting
> stations with different elevation, elevators with exits in different
> levels, ...
>
> Maybe if there are more than one point at the current location the editors
> have to ask which of those you meant to connect. Other mapping programs

Yes... is what i mean, with a particular care when linking the collapsing node 
to others to make segments.

> like MapSource(Garmin) also ask which attribute you meant if you click on a
> spot where more than one poit/attribute would aply.
>
> And more examples would be POIs:
>  - a Hotel, which has also a restaurant
>  - a Food shop which has a Postal office inside

If you have a valid footpath to reach the restaurant, the same is valid to 
reach the hotel, will you think we have to create a bunch of segments 
togheter to have connections for all duplicated nodes?


	Niko