[Talk-GB] Mapquest routing

Philip Barnes phil at trigpoint.me.uk
Fri Mar 9 16:20:37 GMT 2012

On Fri, 2012-03-09 at 13:22 +0000, Andrew wrote:
> Andy Allan <gravitystorm at ...> writes:
> > 
> > I'll bet it's to do with the US.
> > 
> > I think that in the US we are mapping "freeways" as either
> > highway=motorway (for freeways that cross state lines, i.e.
> > Interstates) or highway=trunk (for freeways that don't). So,
> > translating it to the UK, the "avoid freeways" option becomes "avoid
> > motorways", but still disables both highway=motorway and
> > highway=trunk.
> > 
> This is the same problem as Openmtbmap sending bicycles away from 
> highway=trunk roads and is really an ambiguity in the tag. In the US and 
> Germany it is used for less-than-motorway roads but in Britain, although some 
> roads tagged that way are like that, it is very often more-than-primary.
Thanks for that information Andy and Andrew.

That probably explains the reasons, and having looked at areas of Canada
and Germany I am familiar with I can see that the usage of road
classification tags is really not what I was expecting. I have never
driven in the US so cannot really compare anything. 

In Canada the freeways are motorways, but green trunk roads are very few
and far between. The roads I would expect to be trunk are primary, red.
Many roads I would consider tertiary are marked as secondary, I really
would not consider many of them to be B roads. I cannot find any
tertiary roads at all. 

In Germany, the less than motorway road I am familiar with (Blue sign
with a car) between Freiburg and Hinterzarten is tagged as Trunk where
it is a dual carriageway and primary on the single carriagway sections.
If I had been mapping it I would have used the motorway tag, as it has
motorway prohibitions.

Thanks again

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