[OSM-talk-be] Routing in Liège

[Marc Gemis]

Here's Michael's answer: I haven't read it thoroughly yet, so I leave
the interpretation to each of you.

-----
Your impression and the two answers make sence to me. It's hard to
decide the road classification by aerial view. A look beside to google
streetview also doesn't help (and I never would map what I found
there).

May I clear some about that overpass-query?
It only searches for residential, unclassified and tertiary. Higher
road classes are good visible in standard mapstile and lower doesn't
interrest in this case. The colours are blue for residential, orange
for unclassified and green for tertiary. If you zoom in all the
circles get to lines marking the kind of highway. You can move the
bbox on the map and start the query again for any area you want. Don't
use to big areas avoiding brakedown of query.

Okay, most roads have mainly resident buildings beside, but that's not
the only thing to decide about the category. The function in traffic
use is the leading choice for highway value. If a road with lots of
residential buildings beside is connecting towns, villages or parts of
them and is mainly used that way, mapping as a residential makes no
sence, because good routers (and drivers) should try to avoid them if
they don't are at the start or target of route. I often had this
residential mapping at countryside and got strange routes for my
"fast" scooter profile without using motorway and motorroad. That was
the reason I had a look to it. But the problem exists also for cars as
the thread in Mapfactor's forum shows.

And reading the post of Julien, it's clear for my why mappers in
Belgium use the value residential often not in the way the should
according the "leading" english wiki. But discussing about some wiki
specials would fill books and we better use the time to correct
OSM-data and -wiki.

Hope that helped
Regards and wish you get a nice day
---


On Wed, Sep 14, 2016 at 5:52 AM, Marc Gemis <marc.gemis at gmail.com> wrote:
> André, Julien,
>
> thanks for the replies. I've forwarded them to Michael and let hem
> answer your questions/remarks/concerns.
>
> My impression, based on aerial imagery, was that only a couple of
> streets might be classified incorrectly, But it hard to tell without
> knowing the area.
> As for the circles in Overpass, they are caused by very small (OSM)
> ways. There is a command that you can add to the css of Overpass to
> avoid them, but I leave it to Michael to solve.
>
> regards
>
> m