[OSM-talk] Trains and roads

[Cory Lueninghoener]

Here in Chicago we have a fairly well-known elevated train system that
runs in a loop through downtown.  These elevated tracks run exactly
above streets, and thus seem like an easy system to tag: just draw
some segments, and tag a way on them as the street and another way as
the train line.  There's a catch though: several different lines run
on the loop, and they run in different directions.  For example, the
Red Line runs counterclockwise, while the Orange Line runs clockwise.
So, what's the best way to tag this?

Perhaps:
  way 1:
  highway=primary
  name=Wells Street

  way 2:
  railway=subway (yeah, it isn't running underground at the point in question)
  name=Red Line
  oneway=yes

  way 3:
  railway=subway
  name=Orange Line
  direction=reverse
  oneway=yes

Or perhaps more of a divided highway approach is more appropriate,
with each direction of travel having its own set of segments for its
way, as well as a set for the street below them?  I'd prefer to make
use of the same set of segments more than once to more accurately
model the environment though...

-- 
Cory Lueninghoener
Perl, C, & Linux Hacker
http://www.wirelesscouch.net/~cluening/