FYI, I've added a feature request to nominatim https://github.com/twain47/Nominatim/issues/536
michal On Wed, Aug 17, 2016 at 11:00:27PM +0200, Florian Lohoff wrote: > On Wed, Aug 17, 2016 at 01:26:44PM -0700, Daniel Patterson wrote: > > Hi Florian, > > > > This sounds like more of a geocoding problem than a routing problem. > > OSRM itself doesn't know anything about addresses, it only works > > with coordinates and road geometry. All OSRM has internally are > > street names, not street numbers or place names. > > > > In order to route from "Münsterstraße 15a", it must first be turned > > into a coordinate. On the OSM website, the Nominatim service is > > used to do this. Once the web interface has a coordinate for an > > address, it gives that to OSRM for routing. OSRM snaps that point > > to the nearest road, then finds a route. > > > > You might want to do some digging into how Nominatim determines > > address coordinates, and possibly consider adding > > `building=entrance` nodes - this (I think) will cause Nominatim to > > return a more specific location rather than the centroid of the > > building/airport polygon. > > > > Geocoding is a related, but separate problem. There are a bunch of > > tags in OSM that are used by Nominatim, including `building=entrace` > > on nodes, `addr:*` on ways/nodes/relations/areas, etc. Determining > > the best coordinate to return to the user is itself a difficult > > problem. > > I have done a lot of geocoding and i have several OSRM instances running > for different purposes - mostly infrastructure calculation - I am pretty > shure i know the seperate issues well. > > The point is thats an unsolved problem. And its a day to day problem > for me as when i do calculate telecoms cable distances i want the > nearest point on a public road - not the backyard - same problem. > > So yes - Geocoding helps me to find a POI, Address whatever. OSRM is > responsible to bring me there. > > Something in the middle is missing. OSRM/Mapzen/Graphhopper solves halve > of the problem by "snapping to road" which is the brute force > response to this problem - or - to solve the problem of finding the > nearest reachable point on the route graph. Reality is more complex. > > Either routing engines need to get more intelligent or more dumb by > reducing the snap size drastically. Then we would need some "middleware" > which has its own dataset which might be returned by a geocoder > as extended attributes. > > An example response would be: > > I know where "London Zoo" is - Its at lat,lon. If you want to go there > by car use lat2,lon2 - if you want to go there by foot go to lat3,lon3." > > That could be extended for multiple types of transports, infrastructure > connect points whatever. > > In my primary mapping area we decided to avoid "area style POIs" > whenever possible for exactly this reason. Building a centroid on > an area and routing to the nearest point on the routeable network > is most of the time not the right answer. You dont want to end up > in the middle of a multi-acre campsite - you want to be sent to the > reception. > > Flo > -- > Florian Lohoff f...@zz.de > UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away > _______________________________________________ > OSRM-talk mailing list > OSRM-talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/osrm-talk -- michal palenik www.freemap.sk www.oma.sk _______________________________________________ OSRM-talk mailing list OSRM-talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/osrm-talk
