Re: [Talk-GB] Turn Restrictions at roundabouts
Hi Dave, Thanks for answering my original router logic question! :-) On 03/10/2020 17:52, Dave F via Talk-GB wrote: I've just tested in JOSM. It flagged no such validation warning. https://www.openstreetmap.org/way/3403352 Interesting - you're right, I couldn't easily reproduce the 'Sharp Angle' validation warning in the latest JOSM either. After hunting out the code, the warning currently isn't triggered unless the segment leading to a <45deg angle is <10m: https://josm.openstreetmap.de/browser/josm/trunk/src/org/openstreetmap/josm/data/validation/tests/SharpAngles.java Looking at a couple of local roundabouts via imagery, a flare this short verges on a single node highway=mini_roundabout, unless lots of extra nodes have been added to the flare to give a curved approach. After over a dozen years of using JOSM, it still surprises me with extra features. Happy Mapping, James -- James Derrick li...@jamesderrick.org, Cramlington, England I wouldn't be a volunteer if you paid me... https://www.openstreetmap.org/user/James%20Derrick ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
About the only change I've made in years of mapping 'non-mini' roundabouts is to split the oneway=yes flare 'V' into two segments. JOSM validation started flagging the junction node of the V as too tight a bend, which I suppose makes sense. This is a good example of how routing is misunderstood. A continuous way does not imply it should be the preferred route. Likewise, splitting a way doesn't inhibit routing that direction either; it would still be a "sharp angle". I've just tested in JOSM. It flagged no such validation warning. https://www.openstreetmap.org/way/3403352 DaveF ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On Sat, 2020-10-03 at 18:36 +0200, Colin Smale wrote: > On 2020-10-03 18:16, Tom Hughes via Talk-GB wrote: > > On 03/10/2020 16:57, Philip Barnes wrote: > > > > > > > They are intended to stop this type of routing > > > https://www.openstreetmap.org/directions?engine=graphhopper_car=52.64994%2C-1.20491%3B52.64983%2C-1.2049 > > > > > > Which is techincally not illegal and in real world usage is not > > > going to happen. > > > > But unless the start or end point is on the flare why would a > > router do that over the shorter route on the roundabout... I mean > > maybe there are a few cases where the flare is shorter somehow? > > > > If you take that exit by accident, a fast router may tell you to take > the sharp turn back to the roundabout. Some flares are longer than > others, and some routers take longer than others to trigger the "off- > route" stuff. > > But then is it actually illegal? I am begining to wonder if these are mostly attempts to make QA tool tight turn warnings go away? Phil (trigpoint) ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On 2020-10-03 18:16, Tom Hughes via Talk-GB wrote: > On 03/10/2020 16:57, Philip Barnes wrote: > >> They are intended to stop this type of routing >> https://www.openstreetmap.org/directions?engine=graphhopper_car=52.64994%2C-1.20491%3B52.64983%2C-1.2049 >> >> Which is techincally not illegal and in real world usage is not going to >> happen. > > But unless the start or end point is on the flare why would a > router do that over the shorter route on the roundabout... I mean > maybe there are a few cases where the flare is shorter somehow? If you take that exit by accident, a fast router may tell you to take the sharp turn back to the roundabout. Some flares are longer than others, and some routers take longer than others to trigger the "off-route" stuff.___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On 03/10/2020 16:57, Philip Barnes wrote: They are intended to stop this type of routing https://www.openstreetmap.org/directions?engine=graphhopper_car=52.64994%2C-1.20491%3B52.64983%2C-1.2049 Which is techincally not illegal and in real world usage is not going to happen. But unless the start or end point is on the flare why would a router do that over the shorter route on the roundabout... I mean maybe there are a few cases where the flare is shorter somehow? Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On Sat, 2020-10-03 at 16:50 +0100, Tom Hughes via Talk-GB wrote: > On 03/10/2020 14:05, Brian Prangle wrote: > > > There seems to be a predilection for adding turn restrictions , > > either > > no right rurns or no U turns at the exit flares of roundabouts to > > prevent turning back into the entry flares where there are no > > explicit > > signed restrictions. I suspect this is "rendering for routers". Do > > routers actually need this data? I'm tempted just to delete them > > all > > wherever I meet them, but I suspect there are thousands of them > > and > > there'll be howls of complaint. > > Surely if there is a flare then the entry half of the flare will > be one-way against anybody turning off which should exclude it from Tom They are intended to stop this type of routing https://www.openstreetmap.org/directions?engine=graphhopper_car=52.64994%2C-1.20491%3B52.64983%2C-1.2049 Which is techincally not illegal and in real world usage is not going to happen. Phil (trigpoint) ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
Hi, On 03/10/2020 14:05, Brian Prangle wrote: There seems to be a predilection for adding turn restrictions , either no right rurns or no U turns at the exit flares of roundabouts to prevent turning back into the entry flares where there are no explicit signed restrictions. I suspect this is "rendering for routers". Do routers actually need this data? I'm tempted just to delete them all wherever I meet them, but I suspect there are thousands of them and there'll be howls of complaint. About the only change I've made in years of mapping 'non-mini' roundabouts is to split the oneway=yes flare 'V' into two segments. JOSM validation started flagging the junction node of the V as too tight a bend, which I suppose makes sense. I wonder if seeing a junction node of three vertices rather than a 300degree turn on one segment make a difference to roundabout unaware routers? Poor attempt at an ASCII diagram explaining what a two segment flare is below! Flare 1 ->---\ * Road 3 continues away from roundabout Flare 2 -<---/ Flares are the oneway=yes roads connecting to the roundabout. These are often a single V shaped segment, rather than two plus the road. James -- James Derrick li...@jamesderrick.org, Cramlington, England I wouldn't be a volunteer if you paid me... https://www.openstreetmap.org/user/James%20Derrick ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On 03/10/2020 14:05, Brian Prangle wrote: There seems to be a predilection for adding turn restrictions , either no right rurns or no U turns at the exit flares of roundabouts to prevent turning back into the entry flares where there are no explicit signed restrictions. I suspect this is "rendering for routers". Do routers actually need this data? I'm tempted just to delete them all wherever I meet them, but I suspect there are thousands of them and there'll be howls of complaint. Surely if there is a flare then the entry half of the flare will be one-way against anybody turning off which should exclude it from any consideration by a router? Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
Where I've seen them they're on every exit On Sat, 3 Oct 2020, 15:49 Dave F via Talk-GB, wrote: > There is a lot of garbage in OSM due to those creating routers being too > lazy to write a few lines of code, or even use common sense. > > However, in this case I believe it's other contributors who think, for > reasons that escape me, routers require it. > > Routing software must be of a poor standard if it returns the commuter to > the roundabout after just 10 metres or so after leaving it. > > I partially agree with Phil's suggestion that they're harmless, if turn > restrictions are by themselves. However if there are multiple at one > junction it can become error prone. Any that aren't required are best > removed. > > DaveF > > > On 03/10/2020 14:05, Brian Prangle wrote: > > Hi > > There seems to be a predilection for adding turn restrictions , either no > right rurns or no U turns at the exit flares of roundabouts to prevent > turning back into the entry flares where there are no explicit signed > restrictions. I suspect this is "rendering for routers". Do routers > actually need this data? I'm tempted just to delete them all wherever I > meet them, but I suspect there are thousands of them and there'll be howls > of complaint. > > Regards > > Brian > > ___ > Talk-GB mailing > listTalk-GB@openstreetmap.orghttps://lists.openstreetmap.org/listinfo/talk-gb > > > ___ > Talk-GB mailing list > Talk-GB@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-gb > ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
There is a lot of garbage in OSM due to those creating routers being too lazy to write a few lines of code, or even use common sense. However, in this case I believe it's other contributors who think, for reasons that escape me, routers require it. Routing software must be of a poor standard if it returns the commuter to the roundabout after just 10 metres or so after leaving it. I partially agree with Phil's suggestion that they're harmless, if turn restrictions are by themselves. However if there are multiple at one junction it can become error prone. Any that aren't required are best removed. DaveF On 03/10/2020 14:05, Brian Prangle wrote: Hi There seems to be a predilection for adding turn restrictions , either no right rurns or no U turns at the exit flares of roundabouts to prevent turning back into the entry flares where there are no explicit signed restrictions. I suspect this is "rendering for routers". Do routers actually need this data? I'm tempted just to delete them all wherever I meet them, but I suspect there are thousands of them and there'll be howls of complaint. Regards Brian ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
Re: [Talk-GB] Turn Restrictions at roundabouts
On Sat, 2020-10-03 at 14:05 +0100, Brian Prangle wrote: > Hi > > There seems to be a predilection for adding turn restrictions , > either no right rurns or no U turns at the exit flares of roundabouts > to prevent turning back into the entry flares where there are no > explicit signed restrictions. I suspect this is "rendering for > routers". Do routers actually need this data? I'm tempted just to > delete them all wherever I meet them, but I suspect there are > thousands of them and there'll be howls of complaint. > They do seem to be unnecessary and are not legal unless signed. Whilst you may find them playing with routers on a pc, no real world satnav will ever detect that you have taken a wrong turning and reroute within a timeframe that these would ever be an issue. I would probably remove them after survey and it could be worth commenting when mapper adds these asking for reasoning. The danger of removing them without survey is that we could remove a rare real restriction. They are unecessary but harmless IMHO. Phil (trigpoint) ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
[Talk-GB] Turn Restrictions at roundabouts
Hi There seems to be a predilection for adding turn restrictions , either no right rurns or no U turns at the exit flares of roundabouts to prevent turning back into the entry flares where there are no explicit signed restrictions. I suspect this is "rendering for routers". Do routers actually need this data? I'm tempted just to delete them all wherever I meet them, but I suspect there are thousands of them and there'll be howls of complaint. Regards Brian ___ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
