[OSM-talk] Misclassified roads

Steve Hill steve at nexusuk.org
Fri Jul 11 10:19:10 BST 2008

On Fri, 11 Jul 2008, Martijn van Oosterhout wrote:

> But from the your description here, what do you tag
> roads that are 30mph and don't have a centre line? i.e. the single
> most common type here.

That's a bit of a judgement call depending on the situation I think.  Most 
of the streets on housing estates around the UK are wide 20-30mph and many 
have no centre line.  However, they are wide enough to have a centre line 
- I guess the council don't bother painting the lines because they see it 
as unnecessary on a low-speed, low-traffic road and don't want the extra 
costs involved.  I tag these roads as "residential" if they are lined with 

If the road is for just for non-residential access (e.g. access to a 
school, or for deliveries to some shops) and it isn't a through road, I 
tag it as "service"

Some housing estates have quite narrow roads (just wide enough for 2 cars 
to pass) and no footways (so it is a shared surface for cars and 
pedestrians) - I'd tag these as residential.

Rural areas are a bit more problematic - they sometimes have fairly 
narrow roads which are most definately not residential but may have fairly 
low speed limits (30mph), especially around village centres.  I guess I'd 
err on the "unclassified" side even though the speed limit is low.

I hit a problem a few days ago of not quite knowing how to handle the 
difference between an unclassified road (high speed limit, just wide 
enough for cars to pass each other but no centre line) and a very narrow 
road (still a high speed limit, but only 1 car wide and with no passing 
places - if you meet someone coming the other way you'll be reversing for 
a couple of miles!).  In the end I settled on tagging them both as 
unclassified, but setting lanes=1 on the narrow one, but I'm still not 
entirely happy with this since it renders the same.  There was some debate 
as to whether it should be marked as a "track" instead, but tracks are 
supposed to be unsurfaced (and also, they render very similar to 
footpaths which gives the impression that you can't drive down them 
unless you look at the map key).

> Ok, as long as you change nothing in NL I don't really mind one way or
> the other :)


  - Steve
    xmpp:steve at nexusuk.org   sip:steve at nexusuk.org   http://www.nexusuk.org/

      Servatis a periculum, servatis a maleficum - Whisper, Evanescence

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