[sustran] Re: more on motorcycles and congestion

[Eric Bruun]

Mr. Pascal Desmond raises a valid point that motorcycles often
use more "shadow" space in front of them. Whenever possible,
they try to keep tailgaters farther away than auto drivers as well. 
But I think Pascal is assuming a northern European or North 
American traffic operation. I assumed that Walter Hook was refering 
to Asian or Italian operations.  Even though safety and emissions
statistics are wretched, they do use less space by far than
a private car under these circumstances-- This is even more so
when normalized for vehicle occupancy, as many motorcycles and
mopeds will be carrying 2 or 3 people, whereas the car will often
be carrying 1 person plus chauffer (who doesn't count any more
than a bus driver).

Both space consumed while driving and while stored are important.
If one wants to unify the analysis to sum up the consumption of
both, I would like to suggest the time-area method.  It is
summarized in Transportation Research Record 1499.