> -----Original Message----- > From: talk-boun...@openstreetmap.org [mailto:talk- > boun...@openstreetmap.org] On Behalf Of Shaun McDonald > Sent: 31 March 2009 10:39 > To: Ed Loach > Cc: talk@openstreetmap.org > Subject: Re: [OSM-talk] turn restriction relations: via > > > On 31 Mar 2009, at 10:05, Ed Loach wrote: > > > This talk of turn restriction relations reminds me of a junction > > where I think I need to add loads of relations, but to date haven't > > as many of them will include a roundabout as the from or to part. > > > > http://is.gd/pOrJ (shortened permalink) > > > > As you can see there is a roundabout, but there is also a dual > > carriageway through the middle with the flow controlled by traffic > > lights. If you are in the lanes which go through as the dual > > carriageway you can't turn onto the roundabout, and if you are in > > the lanes that lead onto the roundabout you can't turn onto the dual > > carriageway lanes. I think for the relations to work I might have to > > split the roundabout from a closed way into a number of sections, > > but I've always drawn roundabouts as closed ways before. Will > > splitting it cause issues with anything else? Although I might not > > have to split as the via (node) will indicate where the restriction > > actually applies, even when the dual carriageway lane crosses the > > roundabout at two nodes. Or perhaps I could just split the dual > > carriageway lanes somewhere in the middle of the roundabout to make > > things easier for me to work out what restrictions I need to add. > > > > I have seen some people splitting roundabouts so that the bridge can > be shown properly.
Also, there's a roundabout that's split into three separate ways in Canterbury, because it's actually a different road name for each of those ways. I've also seen several examples of roundabouts being split to accommodate bridges, particularly at motorway junctions. > > Comments welcome. I'm undecided between only_straight_on and > > no_left_turn on the dual carriageway segments where they cross the > > roundabout (and on the roundabout where it crosses the dual > > carriageway). I think perhaps the first. Which I think means I need > > to add 8 relations to the junction. > > I think the only straight on restriction might be a better option. > > Shaun > > > > > Ed _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
