On Fri, Jan 10, 2020 at 10:48:02AM +0100, Marc Gemis wrote:
> > OTOH in the dense urban areas you have the problem of Address for road A
> > nearer to Road B. So you get navigated to the wrong spot on the road
> > network.
> I don't understand what this has to do with addresses on buildings vs.
> nodes. I would expect that an address is converted to coordinates. Then a
> route is created to get as close as possible to that point, regardless of
> the street names.
> So yes, if the router does not take services roads, footpaths etc. into
> account (or when they are not mapped), you might end up in the wrong
> street.

Footways are not part of the by car routeable network. And
access=no/access=private or highway=track and neither.

> IMHO, this also does not matter for POIs with an address on a building. The
> satnav should take the coordinates of the POI, not the centre of the
> building in which it is placed. Taking the centre of the (large) building
> might lead to problems.
> So yes, one should try to map as many service roads, paths, internal
> corridors as possible to help routers. And yes, the coordinates taken by
> the router for the endpoint are important.
> but is this caused by addresses on buildings vs. on nodes ? no, not always,
> e.g for (apartment) buildings with multiple entrances with only address
> info on the building, it can go wrong. Not for small detached family houses.

Commercial dataset map addresses back to nodes on the road - On specific
points. We as OSM rely on algorithms to do this automatically - And
fail in an astonishing large amount of cases.

If you go to the center of a park by car there is no way the algorithm
can decide on the best spot to go there by _car_. So it uses the centroid
of the park, tries to find the nearest highway usable by your mode of
transportation. If that happens to be by car you might end up multiple
kilometers away from the optimal place to be. And there is nothing
we can do about it with this level of data abstraction.

The only decision is right now "nearest road with matching mode of
transport" and nearest is in a large number of cases not the place to

Florian Lohoff                                                 f...@zz.de
        UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away

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