2008/10/7 Ed Loach <[EMAIL PROTECTED]>: > This is a roundabout where you can go either way around the "big" > roundabout, and at each junction with a road there is a > mini-roundabout. When these sort of roundabouts, often nicknamed > "Magic Roundabouts" > http://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempstead) > cropped up on this other email list I wondered how they were tagged > in OSM, because of the implied oneway of junction=roundabout.
http://www.openstreetmap.org/?lat=51.562812&lon=-1.77143&zoom=18&layers=B000FTF This is the original Magic Roundabout in Swindon. Here, some licence has been taken with the ways, as you'll see that the "two-way" nature of the flow is implemented here as separate one-way ways. On some sections, this is accurate, as there are real traffic islands. In others, there is just hatching, but since you may not cross it, it's not the biggest tagging sin imaginable. Strictly speaking, the mini-roundabouts should be tagged as such, but I can imagine that would be difficult to do nicely given the dual ways that would converge at each one. Road geeks would contend that Magic Roundabouts are not really roundabouts (apart from the outer minis), but "gyratory traffic systems". The distinction being that they diverge from standard roundabout rules of flow, right-of-way, layout etc., but are still circular. The API seems to be antisocial at the moment, so I can't check the tagging, but my inclination here would be not to tag anything but the 5 outer roundabouts with junction=roundabout. Think of what a routing application might make of it... Dermot -- -------------------------------------- Iren sind menschlich _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
