HI Gerd, that looks like a good start. The attached patch improves on it slightly by ignoring highways that do not have access for cars.

Regards,

Mike

From: Gerd Petermann [mailto:GPetermann_muenchen@hotmail.com]
Sent: 03 August 2016 14:40
To: mkgmap-dev@lists.mkgmap.org.uk
Subject: [mkgmap-dev] [Patch v1] improve roundabout checks

Hi all,

attached is a patch for the roundabout checks. It adds a test that will warn when

a node on a roundabout is connected to more than one routable way

(ways which are not accessable are not counted, e.g. highway=construction with the default style)

The check is only performed when option

--check-roundabouts is used, you have  to enable logging to see the result.
The check is implemented in class RouteNode, so a config line in logging.properties might be

uk.me.parabola.imgfmt.app.net.RouteNode.level=WARN

A binary based on r3688 is here:

http://files.mkgmap.org.uk/download/306/mkgmap.jar

Note that this check is very basic, it doesn't ignore when the road is going straight through the roundabout

or when it builds a tagent. If you think that this produces too many false warning I may add

code for this. 

Gerd