[Talk-GB] Turn Restrictions at roundabouts

[James Derrick]

On 04/10/2020 07:42, Edward Bainton wrote:
> I've been marking them as false positives as to my mind it's obvious 
> that you wouldn't U-turn there (but equally, it would be legal to do so).

You would also probably need a vehicle with a tight turning circle, and 
a quiet road - so agree it would be an unusual choice. Agree false 
positives.

> But the points about machine routing make me think maybe I shouldn't 
> be closing these off? Any thoughts?

Your example looks like a very common roundabout flare 3-way node with a 
cycleway crossing node. Taking the JOSM code as an example, perhaps the 
"ImproveOSM" validation also has a segment length test (<20m?) so the 
crossing is suggesting a more complex junction?

> Eg, at node https://www.openstreetmap.org/node/26187838

Personally, adding restrictions to this common a use-case should be 
unnecessary (fix once in the router, not every roundabout on the map). 
Save your effort for more complex junctions where software 
understandably needs a helping hand with real-world oddities.

Happy Mapping,


James
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James Derrick
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