Re: [OSM-talk] finding settlements where the highways do connect across the settlement
On 04/07/18 20:01, john whelan wrote: I connect them as I come across them I just wondered if anyone had a magic spell to find them? There's a few ways. KeepRight has a "floating islands" feature. OSM Inspect has "Island" (under Routing). But both are only really useful when you're zoomed in a lot, and will show *lots* of errors. There was a site which processed OSM data, and generated "routing islands" listing per country, and listed them all, sorted by length, allowing you to fix the biggest problems first. But I can't find that website! It had a bare bones HTML look, and I know it did Ireland. Rory ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] finding settlements where the highways do connect across the settlement
Hi, On 07/04/2018 10:30 PM, Frederik Ramm wrote: > Andy Allan, > then working for CloudMade, ran a connectivity check Turns out the Wiki is good for something: https://wiki.openstreetmap.org/wiki/TIGER_fixup/250_cities https://wiki.openstreetmap.org/wiki/TIGER_fixup/250_cities/routing_grid 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
Re: [OSM-talk] finding settlements where the highways do connect across the settlement
Hi, On 07/04/2018 06:12 PM, john whelan wrote: > I'm using JOSM and find unconnected highways is useful but in Africa I'm > seeing a number of settlements that have highways entering on both sides > but nothing connecting them which poses problems for routing software. A very very long time ago, when the US data consisted of about 99.9% untouched TIGER import, all road connectivity was broken at every county border. County borders had not yet been imported so you couldn't just mosey along the county boundaries and mend roads either. Andy Allan, then working for CloudMade, ran a connectivity check by building a matrix of (100 by 100? don't remember) bigger cities and compared the routing distance to the bee line distance. Where the routing distance was larger than bee line by a factor of larger than something like 1.5 (don't remember), the entry was highlighted as "potentially affected by a connectivity issue" that humans could then hunt down. I fear the approach will need quite some adaptation to work in rural Africa but maybe it works on the small scale. 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
Re: [OSM-talk] finding settlements where the highways do connect across the settlement
Hi John, This sounds like a fun problem. Thinking as I type, you could... 1. Generate a list of all place names in the area you are interested in, plus a lat/lon location 2. Use the GraphHopper API to route from a known good location to each location in step 1 3. For every location that can be routed to, remove that entry from list generated in step 1 4. Review remaining locations, keep mapping 5. Return to the start This should be reasonable to achieve in your favourite scripting language. Although this is not likely to be the most efficient method, I'm doing something similar for a different problem with reasonable success. I can see this being an enjoyable exercise at least. You may also find KeepRight's "floating islands" check useful: https://wiki.openstreetmap.org/wiki/Keep_Right/130_floating_islands Cheers, Joseph On Wed, 4 Jul 2018 at 19:03, john whelan wrote: > I connect them as I come across them I just wondered if anyone had a magic > spell to find them? > > Thanks John > > On 4 July 2018 at 13:33, Jean-Marc Liotier wrote: > >> On Wed, July 4, 2018 6:12 pm, john whelan wrote: >> > I'm using JOSM and find unconnected highways is useful but in Africa I'm >> > seeing a number of settlements that have highways entering on both sides >> > but nothing connecting them which poses problems for routing software. >> > >> > Any suggestions ? >> >> Connect them ! >> >> Seriously, even if you don't feel like detailing their path across the >> settlement, road network connectivity is worth the urban imprecision... In >> the beginning of Openstreetmap, major ways coming into major cities would >> just meet in the middle ! >> >> Playing with routers such as OSRM is a way I have sometimes stumbled upon >> such cases of disconnection. >> >> > ___ > talk mailing list > talk@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk > ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] finding settlements where the highways do connect across the settlement
I connect them as I come across them I just wondered if anyone had a magic spell to find them? Thanks John On 4 July 2018 at 13:33, Jean-Marc Liotier wrote: > On Wed, July 4, 2018 6:12 pm, john whelan wrote: > > I'm using JOSM and find unconnected highways is useful but in Africa I'm > > seeing a number of settlements that have highways entering on both sides > > but nothing connecting them which poses problems for routing software. > > > > Any suggestions ? > > Connect them ! > > Seriously, even if you don't feel like detailing their path across the > settlement, road network connectivity is worth the urban imprecision... In > the beginning of Openstreetmap, major ways coming into major cities would > just meet in the middle ! > > Playing with routers such as OSRM is a way I have sometimes stumbled upon > such cases of disconnection. > > ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
Re: [OSM-talk] finding settlements where the highways do connect across the settlement
On Wed, July 4, 2018 6:12 pm, john whelan wrote: > I'm using JOSM and find unconnected highways is useful but in Africa I'm > seeing a number of settlements that have highways entering on both sides > but nothing connecting them which poses problems for routing software. > > Any suggestions ? Connect them ! Seriously, even if you don't feel like detailing their path across the settlement, road network connectivity is worth the urban imprecision... In the beginning of Openstreetmap, major ways coming into major cities would just meet in the middle ! Playing with routers such as OSRM is a way I have sometimes stumbled upon such cases of disconnection. ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
[OSM-talk] finding settlements where the highways do connect across the settlement
I'm using JOSM and find unconnected highways is useful but in Africa I'm seeing a number of settlements that have highways entering on both sides but nothing connecting them which poses problems for routing software. Any suggestions? Thanks John ___ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk
