Paul - thanks for the response. I struggle with the idea that someone would know that a route is electrified with a ground level contact system, but not how many rails there are. The possible sources are a) local knowledge, b) wikipedia and c) aerial imagery. All of these will, 9 times out of 10, define the system. Also, there are only 2 networks that I can identify worldwide that are 4th rail, and I've tagged them both already. :-)
best regards, Garry On Thu, 11 Jun 2020 at 12:49, Paul Allen <pla16...@gmail.com> wrote: > On Thu, 11 Jun 2020 at 08:57, Garry Keenor <garry.kee...@gmail.com> wrote: > >> >> Re: using electrified=rail to mean (3rd or 4th rail) >> I'm not in favour of this one - railway electrification engineers (of >> which I am one) do not consider 4th rail to be a special case of 3rd rail, >> but rather a distinct system with its own electrical feeding arrangement. >> It would also run the risk of confusion in the mappers mind - they would >> read as far as electrified=rail in the tag wiki and miss the later option >> for 4th rail. I'm happy to leave electrified=rail to mean 3rd rail if that >> is what the group prefers. >> > > Using electrified=rail to mean 3 rails and having a sub-tag for 4 rails is > a bad > thing. But perhaps there is a case for retaining electrified=rail to mean > "It's > electrified using rails rather than contact line but I don't know how many > rails." > You mentioned that contact lines are often visible on aerial imagery. > Mappers > may know a route is electrified by other means (such as a newspaper article > saying the route has been electrified) but don't know how many rails there > are, > only that there is no sign of a contact line. > > Argument against it: there may be a contact line but the imagery is too > coarse for it to be visible or the mapper doesn't have the skill to > interpret the image correctly so uses electrified=rail where it > should be electrified=yes. > > -- > Paul > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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