On 4 July 2012 09:39, Craig Loftus <[email protected]> wrote:
> > However, there are also instances of highway=no, where roads have been > > realigned or ripped up, should these also be removed from the database? > > I think highway=no is typically used as a temporary tag to try to stop > remote mappers from adding something from a source that is not up to > date. In practice they probably sit around in the database in > perpetuity, but it still seems quite different to actively map > dismantled and abandoned railway lines. > highway=no was a dirty hack suggested as a placeholder for a road name that was in OS Locator that related to a road that didn't exist. Rather than manage a separate DB of such features with all the associated complexity someone suggested we pop it in as a non-road. This is currently often essential for people who which to get to 100% on the OSM Analysis stats we run (http://www.itoworld.com/product/data/osm_analysis/main). > As others have mentioned, railway=dismantled seems fine. However, what > is the argument for keeping connections between sections of dismantled > railway, that have since been split by modern developments? > Personally I would love it if we are able to extract a routable rail network from OSM for certain times in the past. I am sure some railway enthusiast groups will love our historic railway mapping which is better if complete. Here is a project I have proposed which is sitting waiting for some love to digitise the world's historic public transport timetables, and in particular some UK historic railway timetables. ( https://openbradshaws.wordpress.com/) > > As an aside, how would one map a dismantled railway bridge? And, how > would one map an intact but disused bridge from which the railway > tracks have been removed? > My personal preference would be to prefix any tag that is no longer relevant with 'historic:' (rather than the :historic postfix). This would fit with prefixes of proposed: and construction: but this is probably getting to be something that would benefit from being discussed on the tagging list.. For your above example I would like to use: railway=dismantled;bridge=yes (or historic:railway=rail;bridge=yes) If the bridge had been removed I would use: railway=dismantled;historic:bridge=yes (or historic:railway=rail;historic:bridge=yes) If there was a proposed cycle route across a former railway bridge which would have to be rebuilt I would be tempted to use: historic:railway=rail;historic:bridge=yes;proposed:bridge=yes;proposed:highway=cycleway Regards, Peter > > Craig > > On 3 July 2012 22:47, Donald Noble <[email protected]> wrote: > > As someone who has added a few railway=dismantled ways to the map, I > > thought I might add in my reasoning. > > > > Railways, by their nature, link places and are pretty much continuous. > > So in areas (like Glasgow) where there are sections of old railway > > infrastructure visible on the ground I have mapped these as r=disused > > or r=abandoned depending on whether the tracks are still in-situ. But > > I find it useful if these can be linked by sections of r=dismantled > > (or some other tag) that reflects that there was a railway there, even > > if all traces are now gone, as this can make sense of the remnants > > that are there. > > > > I appreciate there is a line between mapping what is on the ground and > > creating a database of historic routes, and perhaps dismantled > > railways crosses that line (if you'll excuse the pun). However, there > > are also instances of highway=no, where roads have been realigned or > > ripped up, should these also be removed from the database? > > > > Personally, I wouldn't map a long section where there once was a > > railway but it has now been completely obliterated by this complex > > housing estate and shopping centre, but I have mapped a place where an > > abandoned railway was obliterated by a carpark but the remains of it > > are visible on either side (and on 3ish year old bing imagery). > > > > This doesn't really address the OP regarding railway:historic=rail > > versus railway=dismantled, which I have no real views on, as neither > > appears on most map renderings. Although I have recently changed a > > couple of railway=station+disused=yes nodes to > > railway:historic=station, where there is no visible evidence left on > > the ground (and so they are no use for navigation), so maybe > > railway:historic=rail keeps things tidier. > > > > regards, Donald > > > > > > -- > > Donald Noble > > http://drnoble.co.uk - http://flickr.com/photos/drnoble > > > > _______________________________________________ > > Talk-GB mailing list > > [email protected] > > http://lists.openstreetmap.org/listinfo/talk-gb > > _______________________________________________ > Talk-GB mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-gb >
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