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Re: Fw: AB1581 Bicycle language for CA MUTCD
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Bob Shanteau
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Jul 21, 2009 09:57 PDT
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Hamed Benouar wrote:
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From your Email, I would like to point out that it appears that we at
least agree on one thing, Caltrans tests showed that when the minimum
16’’reference bicycle is on top of the magnetometer, it is detected
100% of the time ...
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Just to clarify, I did not agree that the reference bicycle (16" wheels
with aluminum rims, non-ferromagnetic frame and stainless steel spokes)
on top of the magnetometer is detected 100% of the time. What I said was
that the bicycle that Kai Leung used in his test must have contained
some ferromagnetic material close enough to the magnetometer to be
detected, which is not consistent with the intent of the proposed
definition of the reference bicycle. It would have been useful if Mr.
Leung had used a magnet to find that ferromagnetic material, but
unfortunately he did not. So it is impossible at this point to determine
whether the bicycle that Mr. Leung used for testing met the definition
of the reference bicycle in the proposed language.
Even if the magnetometer could detect the reference bicycle when the
bicycle is located directly over the top of the magnetometer (and the
location of the magnetometer is marked with a Bicycle Detector Symbol),
this still makes the magnetometer of little use in detecting bicycles at
traffic actuated signals, since the best position for a bicyclist to
stop may not always correspond with the location of the magnetometer
(such as a wide right/through lane or when the bicyclist is traveling at
the speed of traffic).
Bob Shanteau
Transportation Engineering Liaison
California Association of Bicycling Organizations
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