[Talk-GB] Primary or Trunk?

[Shaun McDonald]

On 3 Nov 2013, at 20:17, Robert Norris <rw_norris at hotmail.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!
> 
> Other tags such as lanes=*, width=*, surface=*, maxspeed=* etc... are for more the detailed nuances of route calculations based on the physical properties of the road. Or for how a renderer could choose to emphasize certain roads over others.
> 
> Of course the bendyness of the road should be interfered from the geometry of the node positions themselves.
> 

ITO World make a series of maps which highlight some of the above additional tags that can be added to OSM so that routers can decide whether each road is suitable based on objective data, rather than broad generalisations.

http://www.itoworld.com/map/group/2

Shaun McDonald
Developer
ITO World