[Routing] Improving quality of OSM data for routing.

[Nic Roets]

Let's suppose you physically traveled along road A and where it ends
you turned left in road B (T junction). Except the node at the end of
way A isn't a member of way B according to the OSM database.

For the first 2 points, my program will call Route(). Route() looks
for nodes near these 2 points and see that A is closest to both. So
the route returned is very, very simple and does not even involve an
OSM node.  If A has a slight bend, Route() may say return a route will
1 OSM node. But still no segment.

So the first n points 'belong' to A. But when it's called with n and
n+1, Route() will see n is closest to A and n+1 is closest to B. And
the answer will be to travel back up A, perhaps using a number of
other ways to get to B. Many segments, so these 2 nodes gets flagged
for manual inspection.

On Sun, Aug 24, 2008 at 8:00 PM, David MENTRE <dmentre at linux-france.org> wrote:
> Hello,
>
> "Nic Roets" <nroets at gmail.com> writes:
>
>> So as an application, I wrote a program (osmunda) that scans a GPX
>> tracklog for maneuvers that are 'impossible' according to the given
>> OSM data. Specifically, it takes any two consecutive tracklog points
>> and calculates the route according to OSM data between the two. If
>> this route includes one or more complete segment, it flags the two
>> tracklog points by writing them to another GPX file.
>
> Sorry, I don't understand what you are doing. I understand that you take
> each consecutive pair of GPX points and check them against OSM data. But
> I don't understand your criterion to flag those points as erroneous.
>
> Sincerely yours,
> david
> --
> GPG/PGP key: A3AD7A2A David MENTRE <dmentre at linux-france.org>
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>
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