[Talk-us] braided streets

[Ian Dees]

I've done this before by:

For two split roads intersecting, I make all 4 ways intersect with nodes.
For one split road intersecting with one non-split road, I make 2 nodes for
the intersection.

Does that make sense?

On Mon, Apr 7, 2008 at 7:12 PM, Alan Millar <am12 at bolis.com> wrote:

> > so I see that braided streets are 'officially' a problem
> >
> > http://wiki.openstreetmap.org/index.php/TIGER_fixup
>
> Interesting.  Looking at Google Street View, it looks like these are
> divided streets with an island or restriction running down the middle.  It
> appears the Tiger data has separate segments for each side, with
> intersection nodes where there is a break in the island.
>
> AFAIK Tiger doesn't have the concept of ways like we do; it just has the
> short segments.  I expect that our script takes Tiger segments and
> assembles them into longer ways.  In this case, it appears our script
> didn't know which segments went with which logical ways.
>
> > anyone have a good way of fixing them? I'm happy to have a go in SF.
>
> With 165 streets like that listed on the wiki, I wouldn't want to edit
> them by hand myself.  And those listed are just in SF.  I suspect the
> problem may exist elsewhere also.
>
> I think deleting them and re-uploading them with the script might be
> worthwhile, if there could be some more discrimination or constraints.  I
> could see it being tricky, though.
>
> I can imagine a script that goes through the two ways and identifies the
> average angle of the street, and swaps node membership in the ways to
> match which side it should be on.
>
> Perhaps Dave Hansen has some insight on the Tiger upload script.
>
> Another question is what do we want to do with the intersections?  Should
> it be a single node, or two nodes?  I just dealt with this at:
>
>
> http://informationfreeway.org/?lat=45.553593680216935&lon=-122.68115036884754&zoom=17&layers=B000F000F
>
> In this case it is a split street with light rail tracks down the middle.
> I made it three nodes where the two directions of the street and the
> tracks cross the perpendicular street.  Although logically it is one
> intersection, I think it looks better on the map this way.
>
> - Alan
>
>
>
> _______________________________________________
> Talk-us mailing list
> Talk-us at openstreetmap.org
> http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk-us
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-us/attachments/20080407/f74f5bd5/attachment.html>