Re: [Routing] Roundabouts - why is a separate segment required?
If an entering way shares a node with an exiting way there is no need to pass through a roundabout way to navigate between them hence the roundabout will not be seen. It also messes up the exit count in navigation instructions. Phil (trigpoint) On 14 February 2018 15:38:01 GMT+00:00, Dave F wrote: >To be doubly clear, this is an example of a road entering a roundabout >& >sharing a node with it: > >https://www.openstreetmap.org/node/19091900 > >Dave F. > >On 14/02/2018 15:21, Dave F wrote: >> On 14/02/2018 15:02, Marcus Wolschon wrote: >>> What you describe is a mini-roundabout. >> >> No it wasn't. >> It was perfectly clear as I posted the 'junction=roundabout ' page. >> >> Much of the following is incoherent to me. The rest is irrelevant to >> my point. >> >> DaveF >> >>> That has a different geometry as the center of that one is >traversable. >>> https://wiki.openstreetmap.org/wiki/Tag:highway%3Dmini_roundabout >>> >>> a) >>> I don't see a node as anything you "are on" at any time. Only >segments. >>> At most nodes are considered for calculating the metric of making >>> certain turns >>> between segments. >>> b) >>> Routing algorithms that don't know or deal with roundabouts would >>> still work >>> perfectly well with a circle of segments and give proper >instructions. >>> c) >>> In reality this is a circle of road-segments. So segments represent >>> reality more closely. >>> So for the purpose of the map as a representation of real world >>> geometry, this is simply >>> a much better approximation. This is not only for routing but also >>> for map-rendering >>> to scale the size of the roundabout correctly. (There are vast >>> differences in possible sizes.) >>> d) >>> These segments have a significantly different metric then an >>> intersection (much slower traffic >>> in the roundabout then the surrounding roads). >>> They have an angle to the entering and exiting road that can be used > >>> in a metric because you >>> need to slow down to make such hard turns, limiting your average >>> speed in the segments before and >>> after the roundabout (lookahead). >>> There may be traffic jams or construction sites blocking part of a >>> roundabout but still >>> allowing certain turns to be made. This can not be described with a >>> simple node. >>> >>> >>> On 2018-02-14 15:40, Dave F wrote: Hi Could anyone give me an explanation for this line from https://wiki.openstreetmap.org/wiki/Tag:junction=roundabout "Each road has to be connected with the roundabout in a separate node—that is, between these nodes a segment of the roundabout is required." I see no requirement for a separate segment: * When a entering road shares a node with a roundabout then >the router knows it's entered that roundabout by reading the tags on >the circular way. * Whilst on that node, the router checks to see if there are >any suitable exits. If there are, then it leaves the roundabout. * If not, it continues going around until it finds an >appropriate exit. Cheers DaveF ___ Routing mailing list Routing@openstreetmap.org https://lists.openstreetmap.org/listinfo/routing >> >> >> ___ >> Routing mailing list >> Routing@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/routing > > >___ >Routing mailing list >Routing@openstreetmap.org >https://lists.openstreetmap.org/listinfo/routing -- Sent from my Android device with K-9 Mail. Please excuse my brevity.___ Routing mailing list Routing@openstreetmap.org https://lists.openstreetmap.org/listinfo/routing
Re: [Routing] Routers ignoring speed limits
Thanks Dennis I only tried OSRM in this case, although the original problem of using the A5, rather than A55 was from skobler. I think that one needs some survey work. One thing that was concerning me was the use of maxspeed=signals on the M42. I would have assumed the speed limit should be 70 mph, with a note or some other tag regarding active traffic management? Thanks Phil -- Sent from my Nokia N9 On 04/01/2013 11:39 Dennis Luxen wrote: Hi, the bug was found and fixed in develop branch. https://github.com/DennisOSRM/Project-OSRM/commit/7c54d4e62fc84b29915dc618fd3dba2962752e92 It will be visible on the routing site in the coming 24 hours. Did the bug only affect OSRM or was it visible somewhere else, too? Best regards, Dennis On 04.01.2013 00:48, Philip Barnes wrote: > I began trying this investigation with a bug report in mapdust reporting > a problem with the route calculated between Banbury and Holyhead. It is > using 2 lane trunk roads, in preference to the longer motorway / > expressway route one would expect. > > https://github.com/DennisOSRM/Project-OSRM/commit/7c54d4e62fc84b29915dc618fd3dba2962752e92 > > That maybe ok, its certainly scenic and fun, I then found the real > problem. Speed limits probably need updating, but that is a summer drive > project. > > In forcing the route expected, it came up with the real issue. Instead > of using the motorway around Birmingham, it has used the A34 and gone > straight through the city, projecting both an illegal and impossible > time estimate. > > I have selected a small subset: > https://github.com/DennisOSRM/Project-OSRM/commit/7c54d4e62fc84b29915dc618fd3dba2962752e92 > The route is exactly 1 mile long. > The entire route is tagged as maxspeed=30 mph. > The time estimate is 1 minute, meaning OSRM has assumed an average speed > of 60 mph. > > This is really not good, as far as I can tell the mappers have made a > first rate job. > > Any ideas how we improve? > > > > ___ > Routing mailing list > Routing@openstreetmap.org > https://github.com/DennisOSRM/Project-OSRM/commit/7c54d4e62fc84b29915dc618fd3dba2962752e92 > ___ Routing mailing list Routing@openstreetmap.org https://github.com/DennisOSRM/Project-OSRM/commit/7c54d4e62fc84b29915dc618fd3dba2962752e92 ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
[Routing] Routers ignoring speed limits
I began trying this investigation with a bug report in mapdust reporting a problem with the route calculated between Banbury and Holyhead. It is using 2 lane trunk roads, in preference to the longer motorway / expressway route one would expect. http://map.project-osrm.org/?hl=en&loc=52.072150,-1.317280&loc=53.307430,-4.630270&z=8¢er=52.546296,-4.191284&alt=0&df=0&re=0 That maybe ok, its certainly scenic and fun, I then found the real problem. Speed limits probably need updating, but that is a summer drive project. In forcing the route expected, it came up with the real issue. Instead of using the motorway around Birmingham, it has used the A34 and gone straight through the city, projecting both an illegal and impossible time estimate. I have selected a small subset: http://map.project-osrm.org/?hl=en&loc=52.455950,-1.868190&loc=52.443520,-1.856910&z=15¢er=52.450360,-1.873298&alt=0&df=1&re=0 The route is exactly 1 mile long. The entire route is tagged as maxspeed=30 mph. The time estimate is 1 minute, meaning OSRM has assumed an average speed of 60 mph. This is really not good, as far as I can tell the mappers have made a first rate job. Any ideas how we improve? ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
Re: [Routing] Missing a turn?
On Sat, 2012-11-24 at 18:55 +0100, Colin Smale wrote: > This is probably triggered by the fact that there are two legs of the > junction named Thornton Lane which are assumed to form the > straight-through route, making Main Street a "side road". > > Mkgmap recognises a relation with type=through_route, having two ways > and a node as members (roles not needed) for exactly this case. It works > fine in mkgmap, but I don't believe it is documented anywhere properly > at the moment. Thanks Colin That looks like what we need. I suspect in the dim and distant past this junction was re-engineered to ease traffic flow, my memory goes back about 30 years and it has not changed in that time. Looking at it on the ground, that is clearly what has happened, the right turn from Main Street would have been evil at rush hour. I will investigate through_route further. Thanks Phil ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
[Routing] Missing a turn?
I have been trying to fix this routing problem reported on mapdust, http://www.mapdust.com/detail/3004250. On OSM, it can be seen here http://osm.org/go/eu5TeWZR. Despite its minimal description, I can see exactly what the problem is. Thornton Lane, from the south continues into Main Street. Thornton Lane from the north gives way at the junction. The problem is that routers ignore this turn, I know it is virtually straight, but it is a turn. Travelling north, http://osrm.at/1MH, in the absence of a turn instruction drivers are likely to continue onto Main Street. Is there a way to tag this? Thanks Phil ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
Re: [Routing] Correctness of turn restrictions
On Fri, 2012-11-16 at 10:16 +0100, Tobias Knerr wrote: > On 15.11.2012 05:51, Nelson A. de Oliveira wrote: > > Are there any tools to test the correctness of turn restrictions? (not > > if they are valid (JOSM can validates this), but if the restrictions > > are indeed restricting/allowing what they are supposed to) > > The GraphView plugin for JOSM is intended for this purpose. It makes an > attempt to visualize the routing graph: > > http://wiki.openstreetmap.org/wiki/JOSM/Plugins/GraphView > > It works on the data in JOSM with all local changes, so it doesn't > require the mapper to upload or wait to get a result. > > Whether it's helpful for you probably depends on how easy you find it to > read the visualization. Looks interesting, but one vital thing missing from the wiki page. A download link? Phil ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
Re: [Routing] Ferry routing
On Sun, 2012-07-29 at 01:04 +0200, Nic Roets wrote: > On Sat, Jul 28, 2012 at 11:52 PM, Philip Barnes > wrote: > > Example 3 > http://map.project-osrm.org/10L > > Its that gate I cannot generate a link if I place the > start on the > one-way. But the route generated is via > Hollyhead/Fishguard/Rosslare. > > > http://www.openstreetmap.org/browse/node/1506883412 > access: destination > barrier: gate > > > Are you comfortable changing it to access:yes ? Then that should solve > the routing problem. > Thank you, I am happy to change it. Phil ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
Re: [Routing] Ferry routing
This thread has prompted me to start looking at ferry routing around the UK. I have been using OSRM and have been finding that a big problem is gates and barriers rather than the actual ferry itself. An example is in Dublin, the Hollyhead ferry will route you into the port. But as there is a gate tagged where you leave, routing stops. Example 1 http://map.project-osrm.org/10J Routing is fine, as destination is inside the port. Example 2 http://map.project-osrm.org/10K Routing is via Rosslare. Example 3 http://map.project-osrm.org/10L Its that gate I cannot generate a link if I place the start on the one-way. But the route generated is via Hollyhead/Fishguard/Rosslare. Do I delete the gate, or is there a way to tag it so that it doesn't break routing? I know it is there from a micromapping point of view, but it will be open when a ferry unloads. Phil (trig222) ___ Routing mailing list Routing@openstreetmap.org http://lists.openstreetmap.org/listinfo/routing
