On Fri, Dec 4, 2009 at 4:21 AM, Anthony <o...@inbox.org> wrote: > And I think that's eventually where we're going. The distance between > the centerlines is only part of the equation, but I wouldn't want to > throw that information away. This is all moot, however, because I now > understand that you have no intention of throwing that information > away. The old way of doing things would still be allowed, and in fact > would not be deprecated, right?
Oh, of course. Sorry, I hadn't made that clear. :) In most cases, the trade-off between extreme accuracy, and usability will lead to the simpler divider=* tag. For more complex cases, or where the shape of the individual lanes matters, I'd still make two individual ways. > I think the biggest downside is that it creates two accepted ways to > map the same thing. Even that, I suppose, is not a problem, if we > make it clear that the old way, which contains more information, is > preferable. I think it depends on the circumstance, and whether that information is valuable. If the community feels strongly that duplicated roads are better in most cases, then the divided tag will be marginalised to only the smallest cases, like painted traffic islands. I suspect it will become more popular than that, though. > Your initial email suggested to me that this method of mapping was > superior to the old one. You made a statement, which I agree with, > that "the current practice of duplicating minor roads when there is a > median strip [is] pretty unsatisfactory". So I thought you were > attempting to replace that current practice. Well, put it this way: if this was implemented, I would duplicate far fewer roads in future. I don't know if I would go around converting existing ones, though. I do think it's superior for minor roads where the division is a modern traffic-calming device. > You've clarified that you're not, and it looks like a router/renderer > would be safe ignoring these new tags, so I guess I don't object. If a router ignores the tags, it will occasionally try and send you through a barrier. If a renderer ignores them, then it might be hiding important information from the consumer. But there are certainly already plenty of divided roads which are not marked as such. >Oh yeah, I forgot to mention a big problem. Using forward/backward >breaks when a way is reversed. So divider=u_turn_forward and >divider=u_turn_backward are a bad idea. Yeah I haven't really thought through the u_turn thing much. I think it's awkward for the reason you describe. It's probably better to just have a junction tag that indicates there is a physical gap, and use turn restrictions if you don't want one direction using it. Or just create two lanes, and put a one-way in the right spot. Steve _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
