Dan Wenzel
|
October 24, 2002 |
United States Architectural and Transportation Barriers Compliance Board:
I am writing this letter in opposition to the current proposal to mandate the
placement of audible traffic signals at all intersections with a walk/don’t walk
signal. I also oppose the placement of detectable warnings at every street
crossing without exception. I have worked professionally with blind people of
all ages (birth-senior citizen) for nearly ten years now. For five of those
years I taught travel (Orientation and Mobility) to blind adults and teenagers
at the Colorado Center for the Blind. My personal experience as a blind person
and my professional experience in working with clients who are blind lead me to
the conclusion that in most cases audible traffic signals are unnecessary, and
in some cases may even be more of a safety hazard to the pedestrian. Detectable
warnings at street crossings are also unnecessary for most intersections, unless
the downward slope of the curb, median or island is 1:15 (1 inch for every 15
feet of sidewalk) or less.
A blind person relies on sound cues from the flow of parallel traffic and the
idling of perpendicular traffic that has stopped in order to cross a street
efficiently and safely. Audible traffic signals should not be installed except
on the rare occasion when an intersection has signals, traffic patterns or a
layout that makes it impossible for a blind person to use the traffic cues to
tell when to cross a street and/or to stay within the designated crosswalk. A
vibrotactile indicator should be used instead of an audible traffic signal when
such cases arise. The sound emitted from audible traffic signals make it much
more difficult for the blind person to monitor traffic patterns. The problem is
intensified when you factor in noisy locater tones and add the quieter engines
of newer cars to the mix. The addition of these audible traffic signals will
only add to the confusion of the blind pedestrian, increasing the difficulty to
successfully cross the street.
The masking of traffic cues is not the only problem associated with audible
traffic signals. One past example of a travel lesson I taught with students
illustrates just how problematic an audible traffic signal can be. While working
with two students on crossing intersections in the city of Denver, we came to an
audible signal (I believe the signal was at Broadway and Bates). Both students
had been in the program for a couple of months, so they had the basic
alternative skills of blindness to be able to use traffic to cross a street
safely. In this case, the street we were crossing (Broadway) was much busier
than the parallel street (Bates), so the students had to rely more heavily on
the perpendicular, idling traffic to determine when to cross the intersection.
The audible signal did work when the button was pushed, signaling the students
and myself that it was time to cross. Unfortunately, the signal masked the sound
of the idling traffic, making it extremely difficult to use the stopped traffic
as an indicator that it is truly safe to cross the street. A crucial part of
safely crossing an intersection for any pedestrian is being able to double-check
that traffic has stopped before proceeding across the street. This safety
measure was weakened for us as blind pedestrians because of the difficulty we
had in hearing traffic cues, and this intersection did not even have a locater
tone. The point that audible traffic signals can be confusing was driven home
near the end of the lesson as we headed back to the Colorado Center for the
Blind. The Center was located just North of Illiff on Broadway at that time. We
had some time before class was finished, so I decided to work with the students
on this intersection before returning to the Center. On the Northwest corner of
Illiff and Broadway was a self-serve hand car wash, which was operated by paying
change in order to activate a hose that was used for washing cars. As we stood
at the corner listening for traffic cues to tell us when it was safe to cross,
we heard a beeping sound that lets people know that the time the hose would
squirt water was almost up. The sound that was emitted from this corner car wash
was almost exactly the same sound that we had heard at Broadway and Bates
earlier in the lesson, causing some confusion and difficulty when trying to use
the traffic cues that would enable us to safely cross street. For my money, the
safest way to cross almost all intersections is to use the proven method of
listening for traffic cues.
The installation of audible traffic signals at the vast majority of lighted
intersections and the placement of detectable warnings at most streets will not
have a positive impact on the pedestrian population (disabled or otherwise),
will not lower the incidence of driver error in pedestrian/motorist accidents
and will not make the crossing of most intersections any safer for the blind
pedestrian. Unfortunately, the proponents of audible traffic signals and
detectable warnings have claimed that it is a safety issue for blind people to
not have these audible signals and detectable warnings at intersections. The
fact is that such devises will not lower the incidence of driver error in
auto/pedestrian accidents, and will not provide blind people with the skills
they need to cross intersections safely. The idea that an audible signal will
improve safety is not only misleading, but it can provide the sighted public
with a negative view of the abilities of blind people to safely travel using
alternative techniques. These false perceptions of the abilities of blind people
can have a lasting negative impact when blind people attempt to find jobs and
participate as equal members in society. The best way to ensure the safety of
blind people is to provide them with the skills of blindness needed to safely
locate and cross intersections using environmental and traffic cues. Countless
successful blind students, professionals and leaders throughout the United
States (and the World) employ these techniques to safely travel in all types of
conditions without assistance on daily basis.
I strongly urge contacting and working with the National Federation of the Blind
when determining possible environmental changes or to learn about the abilities
and needs of blind people. Please do not waste time and resources on ineffective
and often hazardous audible traffic signals and unneeded detectable warnings.
Thank you for taking the time to consider this document.
Dan Wenzel
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