[Tagging] Micro Mapping, was Race track

John Smith deltafoxtrot256 at gmail.com
Fri Feb 5 01:32:36 GMT 2010

On 5 February 2010 06:13, Roy Wallace <waldo000000 at gmail.com> wrote:
> But it seems like you're suggesting that the OSM way instead should represent:
> a) if a oneway feature: the centerline
> b) if a twoway feature: the divider between traffic travelling in each direction

I already map the node at the centreline, which isn't nessicarily the
same thing as the midle of the road, this is more likely to be
somewhat accurate if you are driving along the lanes either side of
the centre line, but since we don't have super accurate GPS units yet
it won't be that apparent.

>>>  <way id='-1' visible='true'>
>>>    <nd ref='-1' width='50' lanes:left='2' lanes:right='3' />
>>>    <nd ref='-2' width='40' lanes:left='2' lanes:right='2'  />
>>>  </way>
> Ah now I see what you mean. Can you add all of the necessary tags to
> the example in your diagram? In particular:
> 1) please indicate the geometric interpretation of "width='50'" and
> "width='40'"
> 2) write out the lane tags next to each node. I think you'll quickly
> see that it's difficult to decide how many lanes:right the middle node
> has, i.e. 2 or 3?

The example above was before I realised you'd need 2 widths to
describe things properly in the case of asymmetric lanes. I also
realise the description isn't the best way to do things but I'm having
a hard time thinking of something better, although if we use the
direction of the way we could just tag it left/right...

However to describe the previous diagram in XML it might be something like this:

<?xml version='1.0' encoding='UTF-8'?>
<osm version='0.6' generator='JOSM'>
  <node id='-1' visible='true' lat='-0.17652801739620505'
lon='-3.788568828743543' />
  <node id='-2' visible='true' lat='1.1360435677193206'
lon='-1.0003270145189043' />
  <node id='-4' visible='true' lat='1.1179416038429335'
lon='3.0009810435567132' />
  <way id='-3' action='modify' visible='true'>
    <nd ref='-1'>
       <left lanes='1' width='5' />
       <right lanes='1' width='5' />
    <nd ref='-2'>
       <left lanes='1' width='5' />
       <right lanes='1' width='5' />
    <nd ref='-4'>
       <left lanes='2' width='10' />
       <right lanes='1' width='5' />

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