So it sounds like the general consensus is that I should probably be using "through;right" at places like shown in my original pic, instead of "none;right", based on the usage rather than the signage (presuming, of course, my tagging doesn't conflict with a sign, which shouldn't happen since everyone should be driving like the signs say in the first place).
On Fri, Aug 26, 2016 at 4:17 PM, Jesse B. Crawford <je...@jbcrawford.us> wrote: > Where I live (San Francisco, CA, USA), lane arrows are generally added > for one of two reasons: > > 1) It isn't obvious what the authorized use of a lane is, when there is > e.g. a right, slight right, and through option with various lanes for > each - especially when there are multiple slight_rights as sometimes > happens. > 2) To provide advanced warning that a lane you're in will have limited > options in the future (such as "HWY ONLY" written in lanes). The > location of these warnings varies, they're sometimes just yards before > the intersection and sometimes a block or two back - presumably > depending on how easy a traffic engineer thinks it will be to change lanes. > > Lane arrows are only present in some cases though - and in my > cross-country driving experience, I have found California to be > unusually thorough about lane arrows, so they're probably present more > of the time here than they are in much of the rest of the country. For > example, lane arrows to indicate a merge_to_left are virtually never > used in the state of Oregon (this may even be ODOT policy?), but are > almost always present in California. > > This is just a difference between two neighboring states in a country > with a reasonably precise traffic control manual. Lane arrow practices > are presumably even more different between countries (e.g. in the parts > of Mexico I visit, I don't think I've ever seen one). > > My point is this: the practice of marking lanes with arrows varies by > jurisdiction and by how recently the intersection has been painted. In > many cases, in the US at least, it depends on whether the intersection > is straightforward to navigate for humans or not. It probably also > depends on whether or not violations have been observed there - here, at > least, they sometimes respond to too many accidents at an intersection > by putting in physically larger stop signs. I suspect the same is done > with land arrows. > > Do any of these factors in road markings change the actual ground truth > of the intersection and its navigation? > > I think this is the point that Rihards was getting at, somewhat > hyperbolically. Road markings like lane use arrows and signs are usually > themselves representations of the intersection to come, much like a map. > When we produce a map, we shouldn't be making a map of someone else's > map of the intersection. We should be reflecting the way the > intersection actually is. Which, yes, is sometimes designated only by > restricting signs, but often it is not, and is instead restricted by > standard rules about the usage of lanes (i.e. no right turns from a lane > other than the right curb lane, UNLESS markings indicate otherwise). > These rules, too, vary by jurisdiction, so if the map is going to be > general for global use it should express them. > > -- > Jesse B. Crawford > > https://jbcrawford.us > je...@jbcrawford.us > GPG 0x4085BDC1 > > On 08/25/2016 11:30 PM, Paul Johnson wrote: > > > > > > On Thu, Aug 25, 2016 at 4:28 PM, Rihards <ric...@nakts.net > > <mailto:ric...@nakts.net>> wrote: > > > > On 2016.08.26. 00 <tel:2016.08.26.%2000>:15, Jack Burke wrote: > > > > Freeway exit tagging > > > > > > I am totally confused. > > > > What is the proper method to use turn:lanes to tag freeway lanes > > approaching an exit, where the exit branches directly from an > > edge lane > > without being part of the freeway itself, but the freeway lanes > > are not > > signed with an arrow, such as this one? > > http://mapillary.com/map/im/7igAGXSa6EsUYlTIujXchw > > <http://mapillary.com/map/im/7igAGXSa6EsUYlTIujXchw> > > > > Through examples[1], the wiki shows that when the freeway lanes > > *are* > > signed, then "through;slight_right" appears to be the correct > value. > > The wiki examples also appear to indicate that "through" is > *only* > > appropriate when there is corresponding signage. The wiki is > > also very > > > > > > referencing the previous topic in talk-us about how lane tagging > > should follow lane _markings_, i'd like to suggest to only map the > > legally allowed driving directions, no matter how we arrive at them. > > > > mapping the road markings seems extremely strange - what if they are > > very faded, when do we map them ? is there a threshold of % of the > > paint left ? > > what is there are no road markings but there are signs ? > > do we remove those tags during the winter in some regions ? > > > > mapping of markings separately also seems to have no functional > > benefit. the information should be useful for navigation software - > > or, more importantly, for the end user (no matter which software > > delivers useful service to them). they don't really care how exactly > > the allowed directions are marked, as long as they get through it > > all without crashes and fines. > > > > > > This is a pretty nice summary of what I was getting at in the previous > > thread on talk-us. Especially given how common it is to not have the > > turn arrows in the first place. I'm a firm believer that the wiki is > > wrong on this one and the ground truth for turn lane tagging should be > > the actual application of the lanes, with or without the presence of > > supporting signage or pavement markings. > > > > > > _______________________________________________ > > Talk-us mailing list > > Talk-us@openstreetmap.org > > https://lists.openstreetmap.org/listinfo/talk-us > > > > _______________________________________________ > Talk-us mailing list > Talk-us@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-us >
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