[OSM-newbies] Quality data

[ael]

Iván Sánchez Ortega wrote:
> El Lunes, 3 de Noviembre de 2008, ael escribió:
>> Ok, but while I was waiting for a reply, I found the josm validator page
>> and it allows shared nodes if the ways are tagged with different levels.
>>  So it certainly seems to think that is permitted. The router seems to
>> ignore level tags: perhaps they should be checked and a route flagged as
>> suspect if it "jumps" levels at a common node?
> 
> So entering or exiting a bridge (or tunnel) should raise a warning on the 
> router?

The wiki says that junctions with tunnels and bridges should have short
sections to avoid that sort of ambiguity. I was considering where
different levels *cross*, meaning sections of each way with consistent
levels either side of the shared node. Of course, I  worry about the
complexity of the algorithms that the router would need to employ and
the consequent slowing down: at present it seems pleasingly fast.

Reflecting further on how I got into this habit which is basically
unintuitive, I believe it happened right at the very start when I joined
the project. On my first edit, I had lots of crossing ways. The josm
validator then picked them up as errors/warnings (I don't remember
which), refusing to upload them to the database without explicit
confirmation. It included things like boundaries crossing roads without
a common node in its objections which I now think was really misleading.
I was then so new, that I just assumed that the validator knew better
than I did.

ael