I would suggest it is not necessary to replace the simple node with a circular way. I think it is perfectly acceptable if it is considered as a simple turn instead of negotiating a roundabout, from a routing perspective. An instruction to turn right at the junction would not be improved by an instruction to take the third exit. If the navigator knows that a junction is a mini roundabout, an instruction to turn right at the (mini) roundabout would probably be optimal.
On 23 October 2019 11:35:53 CEST, Florian Lohoff <[email protected]> wrote: >On Wed, Oct 23, 2019 at 09:24:30AM +0000, Philip Barnes wrote: >> On Wednesday, 23 October 2019, Jez Nicholson wrote: >> > So, for those who like definitions: In the UK, a "mini roundabout" >is >> > simply a small roundabout that is either flush to the road or >slightly >> > raised so that large/long vehicles are able drive over it if they >need to. >> > If it has anything on it, like a lamp post, it is a "roundabout". >It is not >> > the size, it is the being able to drive over it that matters >> > >https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/561491/mini-roundabouts-report.pdf >> > >> There is also the rule that you should not do U turns at mini >roundabouts, so it is important that mapping retains this important >distinction. >> >> These are a very common feature, it does seem odd that routers are >not supporting them. > >The point is that a mini roundabout does need a LOT of preprocessing to >put it into some graph for your classical A* or Dijkstra. You need to >eliminate the node and replace it with a circular road much like a >junction. > >Flo >-- >Florian Lohoff [email protected] > UTF-8 Test: The 🐈 ran after a 🐁, but the 🐁 ran away
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