[Tagging] Primary or Trunk?

Fernando Trebien fernando.trebien at gmail.com
Sun Nov 3 19:13:49 UTC 2013

+1 (similar to our discussion here in Brazil)

On Sun, Nov 3, 2013 at 5:07 PM, Jonathan <bigfatfrog67 at gmail.com> wrote:
> Sorry if I've not seen the old posts on this, the wiki pages are
> contradictory which is why I asked the question.
> In the UK we are defining Trunk or Primary based on some arbitrary
> definition not on anything that is of use to any user or renderer.
> What we should be mapping is reality, so that people can use that data to
> build on.  Whether a road is signed in Green, Pink or Purple tells a user
> nothing, it may have a legal definition but that is all.  The tag we give it
> should tell the user something about the road's capabilities, importance,
> size and potential timings/traffic flow.  A Trunk road that is a dual
> carriageway with a maxspeed of 70 mph is very different to a Trunk road that
> winds around fields and has a maxspeed of 50 mph or less!
> Jonathan
> http://bigfatfrog67.me
> On 03/11/2013 00:14, Tom Hughes wrote:
>> On 02/11/13 18:47, Jonathan wrote:
>>> I'm not clear with the distinction of a Trunk road in the UK. The wiki
>>> suggests a trunk road is "high performance roads that don't meet the
>>> requirement for highway
>>> <http://wiki.openstreetmap.org/wiki/Key:highway>=motorway
>>> <http://wiki.openstreetmap.org/wiki/Tag:highway%3Dmotorway>" which to me
>>> would suggest an A road that is a dual carriageway.  Further on in the
>>> wiki it says that any A road in the UK  signed with "Green" signs is a
>>> "Trunk" road.
>>> I know of many "Green" "A" roads that aren't much more than country
>>> lanes, they are definitely not "high performance" and I don't feel they
>>> should be "Trunk" roads, I feel they should be "Primary" roads.
>> It's really very simple, and has been discussed here many, many times
>> before and I'm sure there are multiple pages on the wiki covering it.
>> First, forget the question of which roads are formally designated as trunk
>> roads by the Department for Transport (which is not very many these days).
>> Second, understand that there is something called the Primary Route
>> Network defined by DfT which covers those A roads connecting specific major
>> towns. Those are the A roads with the green signs, and are what we tag as
>> highway=trunk. Other A roads are highway=primary.
>> In many cases those will be major roads, often ex trunk roads, but in more
>> rural areas like the highlands they might look more like a B road does in
>> other parts of the country. That is irrelevant though.
>> In the UK it is really only residential/unclassified/tertiary where you
>> need to make a judgement call. Everything else has a well defined mapping:
>>   Motorways => highway=motorway
>>   Green Signed A Roads => highway=trunk
>>   White Signed A Roads => highway=primary
>>   B Roads => highway=secondary
>> Hopefully that will explain everything ;-)
>> Tom
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Fernando Trebien
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