[Talk-GB] routing on the road network
Hi This is a general question about the current state of the maps. When we use our commercial road networks (OS Mastermap Navteq) for road routing we tend to assume that the roads have been analysed for connectivity, that there are no one-way streets leading to dead ends, that you can't turn left off a flyover onto the road underneath and so forth). we also assume that there is only one link connecting two points if there is only one physical road link, and that all intersections are proper intersections. We have written tools to address check these issues in the past (and clearly not all map makers have always addressed them internally). How suitable is OSM GB for routing, right now, with this level of detail? Do corresponding network analysis tools exist? I did try about 3 months ago to follow details for building a routable network using pgrouting and one of the programs in the chain seemed to do thousands of fixups to the data. If we did such an analysis (which would be quite a big investment) and came to the conclusion there were 10s of thousands of errors - which seems to be entirely possible - would there be any appetite in the community for fixing them? Certainly such an endeavour would be way beyond our budget. Tim -- Tim Pigden Optrak Distribution Software Limited +44 (0)1992 517100 http://www.linkedin.com/in/timpigden http://optrak.com Optrak Distribution Software Ltd is a limited company registered in England and Wales. Company Registration No. 2327613 Registered Offices: Orland House, Mead Lane, Hertford, SG13 7AT England This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Optrak Distribution Software Ltd. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
Hi Tim, I expect that you would find a good appetitie to fix any problems if we can see that this will be highly valued (i.e. used in a great tool), and the bug reports are simple to understand. I'll leave comments about the quality to others, suffice to say that in the Midlands the roads and junctions are mapped well, however turn restrictions are the missing component. Regards, Rob ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
Hi, On 05/16/2012 11:56 AM, Tim Pigden wrote: that there are no one-way streets leading to dead ends, This is not common in OSM but I am not aware of anyone doing a network analysis that would fix such a problem. that you can't turn left off a flyover onto the road underneath In OSM, turning is only possible at nodes, not where two roads happen do cross. Some editors and existing QA tools will whine when you have a non-noded intersection between two roads and neither of them is marked a bridge or tunnel. we also assume that there is only one link connecting two points if there is only one physical road link, Opinions as to what makes up a physical road link may differ, especially when pavements or cycle lanes are concerned. In some countries, people map pavements and cycle lanes as separate geometries (eg http://www.openstreetmap.org/?lat=64.138954lon=-21.922888zoom=18layers=M). and that all intersections are proper intersections. In the GIS world, a proper intersection is often one that is not traversed by any geometry, i.e. you will have roads beginning/ending there but not going through it. In OSM this is different; having a way traverse an intersection is normal and not considered an error. How suitable is OSM GB for routing, right now, with this level of detail? Do corresponding network analysis tools exist? Tools exist but not in one central location. Some potential problems are caught by editors. Then there's OSM Inspector (tools.geofabrik.de/osmi) which has the Skobbler-sponsored routing layer that finds un-connected roads; keepright.at has something similar and also checks for suspect things like service roads branching off of motorways. Powerful project-osrm.org routing engine has the potential to be used as an analysis tool but doesn't produce any automated reports. The restriction analyzer at http://osm.virtuelle-loipe.de/restrictions/ specializes in debugging turn restrictions, and I'm sure there will be more tools I haven't mentioned! I did try about 3 months ago to follow details for building a routable network using pgrouting and one of the programs in the chain seemed to do thousands of fixups to the data. Most likely the program broke up the roads into segments starting/ending at intersections, something that might be a required preprocessing step but nobody would suggest doing that in OSM. OSM is pretty suitable for routing in my opinion. If we did such an analysis (which would be quite a big investment) and came to the conclusion there were 10s of thousands of errors - which seems to be entirely possible - would there be any appetite in the community for fixing them? Certainly such an endeavour would be way beyond our budget. Appetite, yes, but you can also easily chase people away if your system detects too many things where people don't think it's a bug at all, so some tuning might be necessary. One of the weaknesses of most of the existing systems (with the exception of checks in the editor) is that once you fixed the bug, it might take hours or even days for the bug to be properly closed. A system that allows users to hit some kind of re-check this, I've just fixed it button would surely create more enthusiasm for cleaning up your area than most of what we currently have. Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09 E008°23'33 ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
On Wed, 2012-05-16 at 13:42 +0200, Frederik Ramm wrote: Appetite, yes, but you can also easily chase people away if your system detects too many things where people don't think it's a bug at all, so some tuning might be necessary. One of the weaknesses of most of the existing systems (with the exception of checks in the editor) is that once you fixed the bug, it might take hours or even days for the bug to be properly closed. A system that allows users to hit some kind of re-check this, I've just fixed it button would surely create more enthusiasm for cleaning up your area than most of what we currently have. +1 I do go through the mapdust bugs reported by scrobbler users, many are routing errors. One of the big problems is that I can see my map changes almost immediatly but have to wait days before the routers start to use the changes and I can test my changes and hence close the bug. Phil ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
As noted there are some tools available to help find potential errors that effect routing. Have a look on the QA page [1], specifically at keepright, OSM Inspector and MapDust. As for editing OSM and proposing new tags, OpenStreetMap works a bit like wikipedia - we have a very flat structure and work together as a community to tackle issues such as whether new tags are needed or not. Discussions can get a little bit lengthy, but I believe we end up with a better solution in the end. Regards, Rob [1] http://wiki.openstreetmap.org/wiki/Quality_Assurance On , Tim Pigden tim.pig...@optrak.com wrote: Error reporting would definitely be a challenge.Are there existing facilities to add suspect type tags to enable OSM itself to be the primary reporting medium? I haven't looked into the details of editing OSM data but adding new tags seems to require a collective decision. (BTW don't get too excited anyone, this is definitely a long-term project). Tim On 16 May 2012 11:41, Rob Nickerson rob.j.nicker...@gmail.com wrote: Hi Tim, I expect that you would find a good appetitie to fix any problems if we can see that this will be highly valued (ie used in a great tool), and the bug reports are simple to understand. I'll leave comments about the quality to others, suffice to say that in the Midlands the roads and junctions are mapped well, however turn restrictions are the missing component. Regards, Rob ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb -- Tim Pigden Optrak Distribution Software Limited +44 (0)1992 517100 http://www.linkedin.com/in/timpigden http://optrak.com Optrak Distribution Software Ltd is a limited company registered in England and Wales. Company Registration No. 2327613 Registered Offices: Orland House, Mead Lane, Hertford, SG13 7AT England This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Optrak Distribution Software Ltd. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
On 16 May 2012 12:42, Frederik Ramm frede...@remote.org wrote: On 05/16/2012 11:56 AM, Tim Pigden wrote: that there are no one-way streets leading to dead ends, This is not common in OSM but I am not aware of anyone doing a network analysis that would fix such a problem. Keepright has this check - dead-ended one-ways Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] routing on the road network
I don't think the email below made it to the list: On , Tim Pigden tim.pig...@optrak.com wrote: Error reporting would definitely be a challenge.Are there existing facilities to add suspect type tags to enable OSM itself to be the primary reporting medium? I haven't looked into the details of editing OSM data but adding new tags seems to require a collective decision. Please don't add bug reports to the OSM database itself, whether through suspect tags or similar. I expect anything like that would lead to getting blocked pretty quickly! There's a variety of existing bug reporting / QA toolchains - Keepright, OSB, Mapdust - for everything from auto-generated calculations to end-user reports. It's best to pick one of them, and add your additional insights to that. Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
