E.g. Gamlebrua is a bridge that is physically limited to 200 cm width. Passing it with a 2m wide vehicle is legal, but my guess is that most GPS users would prefer an alternative route. How should I mark up that? Marking it as 'cars not allowed' would be useful, but not entirely true. asked 04 Aug '16, 10:39  Styrheim edited 04 Aug '16, 18:54  aseerel4c26 ♦ |
3 Answers:
Use maxwidth=2 if this is the legal limit. Usually we tag the legal state as well as the physical state of the road (surface, smoothness, tracktype, maxspeed, maxspeed:practical, maxheight, maxweight and so on). We don't tag "suggestions" like "avoid the road if possible", this is the task of the routing engine. answered 04 Aug '16, 10:51  scai ♦ edited 07 Aug '16, 15:57 showing 5 of 6 show 1 more comments |
You could use I guess the bridge is physically at least some centimetres wider than the legal restriction. So, maybe this:
answered 04 Aug '16, 18:56 aseerel4c26 ♦ edited 05 Aug '16, 19:52 |
In that case use the answered 04 Aug '16, 12:16  rorym |
Wait, OP didn't confirm that there is a legal max width. We can only put maxwidth=200 if there is a sign, right? In case of just a practical limit, then it should be maxwidth:physical= or just width= if I understand the wiki correctly. For that matter, I don't see why we would need the new and seldom used maxwidth:physical= when we already have width=.
You are right. If there is no legal limit then maxwidth is wrong and should not be used.
Regarding width and maxwidth:physical: This is a good question and the wiki description is not clear. In my opinion width specifies the width of the road/path. This is equal to the maximum possible track width of the vehicle passing this road. However the vehicle itself could be somewhat larger. Imagine a road being 2 meters width, thus allowing only vehicles with a track width of 2 meters. Still it could allow vehicles with an actual width of 2.2 meters to pass. In this case one could use the tags width=2 and maxwitdh:physical=2.2. But that's just a guess, not sure if this would be really correct. This is better asked in a separate question.
@scai: I would think of
maxwidth:pysicalof the maximal width a vehicle could have.widthis the width of the feature. In case of a bridge that may be significantly more due to construction elements/cage. Or iswidthon a typical bridge object in OSM the "track width" as you reason? I think it is not clear. What is the extent ofwidthfor that bridge picture?maxwidth:physicalseems to be more clear to me. Full disclosure: I created that wiki page of a not yet widely used tag … as I just noticed. ;-)@aseerel4c26 That's what I tried (and maybe failed) to explain. Yes, in my opinion
widthis the same as the track width of a vehicle since a vehicle can't drive on a road that is smaller than it's track width. For the bridge in your picturemaxwidth:physicalis IHMO a few centimeters larger thanwidth.@scai: thanks. And the track width is the outside width of the track/tires?
I think
widthis quite undefined what it means if tagged to a bridge. Which is the feature, which is described by width? Is ithighway=unclassified(for example) or is it the wholehighway=unclassified+bridge=yes?In the past, when I tagged
widthonto ahighway=residentialI measured the width of the road, from curb to curb. If that is right – I do not know. What ifsidewalk=bothis tagged, too?@@aseerel4c26 Yes, track width is the distance between the vehicle's tyres. But I think it is usually calculated based on the wheel's center which makes it a little more awkward.
If a road has a
widthtag and alsosidewalktags then in my opinion thewidthjust applies to the actual road and not to the sidewalk. The sidewalk's width must be tagged separately usingsidewalk:widthorsidewalk:left:width+sidewalk:right:width. So measuring a road's width from curb to curb sounds right.