[talk-au] Roundabout tagging

Brent Easton b.easton at exemail.com.au
Thu Sep 20 04:17:31 BST 2007

*********** REPLY SEPARATOR  ***********

On 20/09/2007 at 1:02 PM Ian Sergeant  wrote:

>b.easton at uws.edu.au wrote:
>> Use highway=mini_roundabout for all roundabouts except the largest
>> variety involving dual carriage ways and/or having a sizeable (?)
>> piece of land in the middle.
>> As opposed to the current guidelines of:
>> Use junction=roundabout for anything larger than a circle of white
>> paint on the ground.
>A mini_roundabout in the UK can be a white painted circle but a
>mini_roundabout in Australia is likely to be a round concrete mound around
>3-5m in diameter generally within the road width.

Yep, those are the ones I am thinking of.

>Anything more than that, and I tend to try and map the roundabout if I have
>a complete trace of the roundabout. However, I can understand why its
>sometimes easier to just use mini_roundabout as a first pass.
>"Franc Carter" <franc.carter at gmail.com>  wrote:
>> Just to throw the initial thought process out there, let's think about
>what a
>> 'wayed roundabout' gives us that a noded-one doesn't - any ideas other
>> than size ?
>I'm a card carrying memeber of the "Just map what is on the ground, and let
>the user/renderer/router worry about everything else" faction.

Yes, but there is a limit to that. In reality, we do not map every single turning lane, slip lane etc. I think it is more important to map the 'funcionality' of a junction, rather than the precise alignment of every piece of asphalt.

>But for example, while cycling, I would cycle with the kids through a
>mini_roundabout on a quiet road, even if it was a major road juntion.  If
>there was a larger roundabout crossing a major road, I would avoid it, as I
>would have to cycle with the traffic around the roundabout.

Exactly. I am not saying make every roundabout a mini-roundabout, but as you say above, there is a class of roundabouts that are 'more than a white circle of paint on the road' that we should consider as mini-roundabouts. 

I think your comment about 'within the road width' is key. 

>P.S. In my experience the JOSM "arrange nodes in a circle" generates nice
>roundabouts, usually.

Brent Easton                       
University of Western Sydney                                   
Email: b.easton at uws.edu.au

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