On 2018-02-14 15:53, 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.

I'm not sure if you read the requirement right, but this tells mappers not to connect the entry and exit road on the same node. If you were to map it that way, the router will not see that you enter a roundabout and need to exit at the first exit. It will just tell you to go right. It is not (what I think you think) that there needs to be a separate way between entrance and exit, the roundabout can be mapped as one way in total.

Maarten

_______________________________________________
talk mailing list
talk@openstreetmap.org
https://lists.openstreetmap.org/listinfo/talk

Reply via email to