[sustran] Bicycles - Improving the image

Eric Bruun ebruun at rci.rutgers.edu
Sat Apr 18 00:08:27 JST 1998


I think the space efficiency of bicycles you quoted, at 
only twice as good per lane mile as an auto, is not correct.
Bicycles do not need the lane width, nor do they have to 
travel single file, rather they can move in formation
like a squadron of fighter aircraft.

I would like to suggest using the time-area approach where
the vehicle's own space, the shadow it occupies for maintaining
a safe distance and the time for which it occupies the space
are analyzed simultaneously. Furthermore, this method unifies
the space occupied for parking with the space occupied while
traveling to get the entire impact on the area in question.
Using this method, I find bicycles to be very space efficient.
Cars are very poor, not just because of their size, but because
as speed increases, the standoff distance increases, not to
mention their extremely high parking requirements.

The time-area method is described in Bruun and Vuchic, "Time
-Area Concept: Development, Meaning, and Application," 
Transportation Research Record 1499, 1995. The article
does not show the bicycle computation, but you will get the
idea. A little bit of effort is required to adjust for the 
fact that bicycles do not have to travel single file. 

Thus, I submit that from a space standpoint, bicyclese are
superior. In fact, the wall of bicycles one sees on 
roads in China is an order of magnitude more efficient
than if cars were traveling single file in however many
lanes one could fit in the right of way.

Eric



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