[OSM-talk] re-using segments

[Karl Newman]

On Jan 5, 2008 2:24 AM, Karl Eichwalder <ke at gnu.franken.de> wrote:
> >> Am I btw correct in thinking that with the new three-layered way of
> >> tagging things (nodes-ways-relations) that it's best to have split ways
> >> on every node where another way meets it? So, instead of one big way
> >> long as I used to tag things, now a separate way between every
> >> crossroad?
>
> > I hope that's not being encouraged. Ways should not be split just
> > because there's an intersection. Ways should be split only when the
> > properties of the way change (i.e., speed limit changes, or way goes
> > over a bridge, etc.). Having lots of little streets is almost like
> > having segments again. It's not very efficient.
>
> It depends.  If you agree to split streets because of bridges or
> speed limit changes, you should also allow splitting because of
> routes.  Take into account that speed limits are often useful for
> fuel powered vehicles.

Splitting ways for a route seems to be necessary. I was primarily
objecting to splitting the way at every intersection, for no other
reason than it's an intersection. But this trend of splitting ways is
troubling. In the degenerate case, ways become what segments were.
Split ways are much harder to maintain than one long way. Maybe we
should consider a method of tagging sub-sections of a way (i.e., this
route is part of that way from node A to node B), although I know that
has its own problems.

Karl