[OSM-talk] Advanced highway tagging

[Andrew MacKinnon]

On Nov 20, 2007 8:07 PM, Thomas Walraet <thomas at walraet.com> wrote:
> Karl Newman wrote:
> >
> >> All commercial online maps decide which roads are major and which are
> >> minor on a subjective basis.
> >
> > I would bet that they actually are derived from some objective
> > factors; those factors just may not be known or obvious.
>
> I'm not so sure. On common printed map, everything seems decided by a
> cartographer (what to draw, where to put the names, etc.). On online
> maps this is probably decided roughly by an algorithm but with the
> addition of manual hinting.

It was precisely this "manual hinting" that I was proposing that we
add. However, the community seems to think that this should be done
completely automatically.

> Doing this automatically from OSM data could be a nice end-project for a
> student.

Now, we need to consider how to represent a highway's official
designation in the database. Clearly, the
motorway/trunk/primary/secondary/tertiary/unclassified scheme isn't
detailed enough. Factors that we might want to indicate in the
database:

- What level of government manages the road? (The national government?
The state/provincial/regional government? The local government? A
private corporation/landholder?)
-- What is the specific jurisdiction that manages the road (so we can
use the correct symbol - e.g. a Quebec autoroute and an Ontario
freeway are signed differently)
- What category of road is it? e.g. for Canada, we have:
-- Provincial motorway
-- Municipal motorway
-- Provincial primary highway
-- Provincial secondary highway
-- Provincial tertiary highway
-- Municipal road - ranging from
- Is it a designated route (e.g. scenic route, "Trans-Canada Highway")?
- What is its former designation? (designations change, often for
political reasons)