[Tagging] Divided highways, and not so divided highways, one way or two

Snusmumriken snusmumriken.mapper at runbox.com
Fri Oct 11 08:24:29 UTC 2019

On Thu, 2019-10-10 at 17:57 +0200, Martin Koppenhoefer wrote:
> Am Do., 10. Okt. 2019 um 16:10 Uhr schrieb Snusmumriken <
> snusmumriken.mapper at runbox.com>:
> > For example if you try to create a routing advice for a car
> > journey.
> > Let's say that the journey starts at Main street number 10 and that
> > Main street is a two way street where the two directions are
> > legally
> > separated. Let's say that number 10 is on the right-hand side of
> > the
> > road and we are in a country that drives on the right side. Let's
> > further say that the shortest way to the destination would be to
> > cross
> > the legal separation and take left. But that would be illegal. But
> > there is no way the routing engine could know that. Unless the two
> > directions are separated.
> or the kind of legal separation is mapped so that the software could
> know. 
> Or you park your car on the opposite side of the road and cross it as
> a pedestrian. Or maybe you'll finding a free parking spot much
> farther away and have to walk quite a bit. Or maybe they drive on the
> left, you're the prime minister, and your driver will park the car...
> Of course it does not matter for those cases where you may not cross
> the divider legally and you do not plan to do so, and it is mapped as
> if you could not even physically, but there are usecases where you
> might want to either cross illegally, or you have the special right
> to do so, and then it should be possible to determine whether there
> is a physical possibility or not.

You have to remember that some physical separation are just as easy to
cross as a painted line. 

A level strip of grass can be crossed by any car. With a big SUV you
can cross curbs and so on. It's just a questions about how big your car
is and the nature of the physical separation. But I don't think that
OSM should be about that, but rather to be a map database to be able to
provide a _legal_ route from A to B.

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