Hi, On 28.09.2018 23:21, john whelan wrote: > Many cities have had their bus stops imported.
And even more cities have their bus stops mapped in the traditional fashion, like, riding a bus and recording where it stops. It's amazing how much you can do with one day pass :) > what else is needed to work it out? Many standard routing tools (Graphhopper, OSRM, Valhalla) can do "isochrones", that is essentially what you are looking for for one single bus stop. You would simply run that for every bus stop and join the results together. Since you don't need instant results and you don't want to run this for a whole country, the algorithm to use is really simple - build a routing graph, annotate each bus stop node with a travel time of "0", and travel outwards along all reachable nodes, increasing your travel time by the time it takes to walk the edge you are using, until you reach a node that already has a smaller time annotation than you have accumulated. There's a simple Perl implementation in svn.openstreetmap.org/applications/utils/distance_maps that could be used as a basis if Perl is your thing but you could use pg_routing just as well. Having said that: 1. In the concrete example of a hospital, I would expect the local bus operator to create a new bus stop or even change a bus route to accommodate the hospital. Of course this would not work if you wanted to set up a bakery. 2. The existence of a bus stop in OSM does not mean it is actually served by a route; and the existence of a route in OSM that serves the bus stop does not necessarily say what frequency - it could be the school bus that only goes three times a day, or the night bus, or the bus extension to the pool that only goes in summer. Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33" _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk