Re: [Talk-GB] Rebooting the NAPTAN import?
On 03/04/11 14:19, Stuart Grimshaw wrote: On Sat, Apr 2, 2011 at 4:37 PM, Jerry Clough : SK53 on OSM wrote: a) Do not import any NaPTAN data in areas where imports have already taken place. Experience shows that detailed survey& correction of NaPTAN data is not to be undertaken lightly. IIRC about 10% is wrong. The best data are for Hullwhere Chris Hill surveyed the lot. I have done only about 20% of Nottingham's NaPTAN stops and have a similar error rate. Unfortunately processing NaPTAN alongside primary surveying just didnt prove viable, but there are plenty of stops which no longer exist, have moved or dont exist on the ground. b) Check with any mappers in the area before performing an import. There may be good reasons why they have not requested one in the past. c) The best approach would be to host current NaPTAN data in a location where OSM data can be compared& then mappers could choose to import it. Having an application which did this would be way more useful than shoehorning NaPTAN data in on its own. I think this is a great idea Jerry, an app for people to compare what OSM holds already against what's in the latest version of NAPTAN, the data we were looking at was a few days old. What's the maximum area or number of points a tool like this would normally import? You don't want someone just selecting the whole of the UK& then importing them. I much prefer Andy's idea of an editor overlay. Then no data is directly imported into OSM, but data can be selectively compared and copied from a data layer to use stops and other features, such as stop areas, where someone is interested. Surveying the whole of a city, even a smallish one having about 1300 stops, to verify its NaPTAN import was a ridiculously large task, being able to copy a much smaller area would have made much more sense. That way someone could copy the stops for a bus route or around a neighbourhood and work on those and it would be easier to manage for multiple people working in one area. -- Cheers, Chris user: chillly ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Rebooting the NAPTAN import?
On Sat, Apr 2, 2011 at 4:37 PM, Jerry Clough : SK53 on OSM wrote: > > a) Do not import any NaPTAN data in areas where imports have already taken > place. Experience shows that detailed survey & correction of NaPTAN data is > not to be undertaken lightly. IIRC about 10% is wrong. The best data are for > Hullwhere Chris Hill surveyed the lot. I have done only about 20% of > Nottingham's NaPTAN stops and have a similar error rate. Unfortunately > processing NaPTAN alongside primary surveying just didnt prove viable, but > there are plenty of stops which no longer exist, have moved or dont exist on > the ground. > b) Check with any mappers in the area before performing an import. There may > be good reasons why they have not requested one in the past. > c) The best approach would be to host current NaPTAN data in a location > where OSM data can be compared & then mappers could choose to import it. > Having an application which did this would be way more useful than > shoehorning NaPTAN data in on its own. I think this is a great idea Jerry, an app for people to compare what OSM holds already against what's in the latest version of NAPTAN, the data we were looking at was a few days old. What's the maximum area or number of points a tool like this would normally import? You don't want someone just selecting the whole of the UK & then importing them. ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Rebooting the NAPTAN import?
The "audit" might also identify area champions. I feel that I have a pretty good eye on what is happening in my Borough (Enfield) and try to be actively maintaining the data for it (possibly less well in southern edge of Borough). Would it help to see what parts of London have similar active community monitors in place? Cheers STEVE From: Tom Chance [t...@acrewoods.net] Sent: Sunday, April 03, 2011 11:28 AM To: Andy Allan Cc: talk-gb@openstreetmap.org Subject: Re: [Talk-GB] Rebooting the NAPTAN import? On 3 April 2011 10:28, Andy Allan mailto:gravityst...@gmail.com>> wrote: I've found this in swathes of south London - pairs of naptan and non-naptan bus stops along major roads, suggesting that it's been years of things not being fixed up before I noticed. I was quite surprised to see that given that London is one of our most actively-mapped areas! One reason is probably that swathes of south London were mapped in parties pre:NAPTAN and haven't seen much comprehensive love since then from local mappers. I've noticed many of the bus stop pairs in areas that also still have TimC's very roughly traced residential areas and a thin smattering of POIs. It would be interesting to use these bus stop pairs (and the verified tag on NAPTAP stops); the OS Locator comparison tools; perhaps POI density and TimC's residential areas; all to produce an audit of the OSM community in London... which areas are receiving active attention, and which are just improved occasionally by people passing through? My perception is that in Southwark, for example, only about a third of it is "actively mapped". Regards, Tom -- http://tom.acrewoods.net http://twitter.com/tom_chance ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Rebooting the NAPTAN import?
On 3 April 2011 10:28, Andy Allan wrote: > I've found this in swathes of south London - pairs of naptan and > non-naptan bus stops along major roads, suggesting that it's been > years of things not being fixed up before I noticed. I was quite > surprised to see that given that London is one of our most > actively-mapped areas! One reason is probably that swathes of south London were mapped in parties pre:NAPTAN and haven't seen much comprehensive love since then from local mappers. I've noticed many of the bus stop pairs in areas that also still have TimC's very roughly traced residential areas and a thin smattering of POIs. It would be interesting to use these bus stop pairs (and the verified tag on NAPTAP stops); the OS Locator comparison tools; perhaps POI density and TimC's residential areas; all to produce an audit of the OSM community in London... which areas are receiving active attention, and which are just improved occasionally by people passing through? My perception is that in Southwark, for example, only about a third of it is "actively mapped". Regards, Tom -- http://tom.acrewoods.net http://twitter.com/tom_chance ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Rebooting the NAPTAN import?
On Sat, Apr 2, 2011 at 4:37 PM, Jerry Clough : SK53 on OSM wrote: > c) The best approach would be to host current NaPTAN data in a location > where OSM data can be compared & then mappers could choose to import it. > Having an application which did this would be way more useful than > shoehorning NaPTAN data in on its own. Potlatch2 has the ability to read appropriately-preprocessed Vector Background layers, which allows mappers to pick and choose which bits of a datasource to "import" and where to simply copy tags over. It's a promising approach to follow. > You can see this where a NaPTAN stop & a previously mapped stop exist close > together. An import will either sit in the database gathering dust, or it > will impose a substantial workload on local mappers if they want to check > it. I've found this in swathes of south London - pairs of naptan and non-naptan bus stops along major roads, suggesting that it's been years of things not being fixed up before I noticed. I was quite surprised to see that given that London is one of our most actively-mapped areas! Cheers, Andy ___ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
