[OSM-talk] Should Bridges be independent of their ways?

[Anthony]

On Sun, Sep 20, 2009 at 10:04 AM, John Smith <deltafoxtrot256 at gmail.com>wrote:

> 2009/9/20 Anthony <osm at inbox.org>:
>
> > Yes they are.  If they weren't physically separated, people would be
> driving
> > on top of each other.  If they weren't physically separated, they
> wouldn't
> > be called multiple lanes - they'd be called one lane.
>
> Pretty sure I left an "if" out, if the lanes are on top of the same
> physical thing, in this case a bridge it's a single way, just the
> lanes need tagging differently.
>

So this is a single way?
http://bikelaneblog.files.wordpress.com/2008/02/pulaski-bridge-walkway.jpg?w=324&h=241

That's nutty.


> > The maxspeed of a way is the maximum speed you can legally travel on that
> > way.  There's nothing inaccurate about tagging the way with the maximum
> > speed you can legally travel on it.
>
> That isn't accurate, the maximum speed varies by lane. Instead of
> maxspeed, what about maxheight, if several lanes have different
> maxheights it would be inaccurate and incorrect to mark either the
> highest or lowest maxheight since you might fit if you get in the
> right lane.
>

As long as you are free to change lanes, I disagree.  The maxheight of a way
is the maximum height of the way.  Using a GPS doesn't permit you to ignore
signs which say to stay out of the right lane.

Now if there's routing information involved - if you can't switch lanes -
then yes, this is important information.  But it's also the place for more
than one way.


> > Everything in the world is physically connected.  In this case, let's
> leave
> > out the cycle lane and footpath and just consider a dual carriage way
> (with
> > central reservation).  There are two roads and an island which go over
> one
> > bridge.  One way, two, or three?
>
> Is it one bridge or 2 bridges, if it's one bridge it's a single way
> with multiple lanes.
>

Have you ever been on a bridge with a Jersey barrier?  Is that one bridge,
or two?


> > One way is unacceptable.  If that's your proposal, it is to rewrite all
> the
> > editors and all the routing software, and then go through the database
> > combining all the dual carriageways which many of us worked hard to split
> up
> > in the first place.
>
> You really need to read my comments instead of making assumptions,
> dual carriage ways usually aren't phycially connected, not in the same
> respect as a bridge.
>

Searching Google for "physically separated", I have some examples.  Are any
of these examples of a single way?

http://www.flickr.com/photos/portlandtransport/3877499480/sizes/m/in/set-72157622203417368/
http://www.uppergreenside.org/wp-content/uploads/2007/03/physically-separated-bike-lanes-diagram.jpg
http://bikelaneblog.files.wordpress.com/2008/03/9th-ave-with-platic-barriers.jpg
http://bikelaneblog.files.wordpress.com/2008/02/pulaski-bridge-walkway.jpg?w=324&h=241
http://2.bp.blogspot.com/_kvgPyMB-iIs/SWkOfoVQVEI/AAAAAAAADbA/3lCHczbQ700/s320/pinest_physical_bike-1.jpg
http://www.streetsblog.org/wp-content/uploads/moved/buffered_bike_lane4.jpg
http://www.transitmiami.com/wp-content/uploads/2009/08/Miami-Bicycle-Survey-384-1024x768.jpg
http://i.treehugger.com/images/2007/10/24/new%20york%20bike%20lane.jpg
http://farm3.static.flickr.com/2399/2367382978_f878d69045.jpg

Maybe the last one.  Anything else, is "physically separated", but could
easily be accomplished over a single bridge (one of them even *is* an
example of a single bridge).
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