On 9/19/2011 10:39 AM, Gerhard Hermanns wrote:
Am 19.09.2011 13:29, schrieb Nathan Edgars II:
Can someone give an example of a case where the number of lanes,
including turning lanes, on a road would be more useful than just the
through lanes, and where another tag (such as width) would not be even
more useful? I'm unable to think of such a case.
Traffic simulation (e.g. by cellular automata) is a use case for this.
At crossroads it can make a huge difference for traffic engineering to
know if a (turn) lane can contain 3 or 30 vehicles.
To determine the "capacity" of a turn lane one would need information
about its length - and one would get this easily if start and end point
of the lane are known. Otherwise one would have to tag something like
"turn_lane_left_1=xx" and "turn_lane_left_2=yy" (indicating length or
capacity or whatever) in case of two turn lanes with different lengths.
This would require much more than just the number of lanes. In fact,
wouldn't it be easier to tag directly how long each turn lane is for
each approach rather than splitting the way in several places?
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