Spring 2007 Newsletter, AER
Orientation and Mobility Division
Strategies that blind people traditionally
use to cross at signalized intersections are no longer effective and reliable, because
of drastic changes that have been made in signalized intersections during the
last 30 years. For example, research at actuated intersections showed that blind
pedestrians using traditional strategies may begin crossing when turning
traffic has the right-of-way across their crosswalk, and if they have not
pushed the pedestrian button they may not have adequate time to complete their
crossing before the signal changes (Barlow, Bentzen,
& Bond 2005).
Some of the features of modern traffic
signals that are now different are:
·
Complex traffic patterns (protected left and split phases, lead pedestrian
intervals, exclusive pedestrian phases)
Effect: Traditional strategy to “cross with parallel traffic
surge” is no longer reliably appropriate or safe.
Effect: Initial surge
of parallel traffic is no longer sufficient cue to recognize the onset of the
pedestrian walk signal.
Effects:
1. It is no longer possible to predict timing / traffic
pattern, no matter how long it is observed;
2.
Pedestrians may
have to push a
button to ensure enough time to cross, in which case the crossing must
start in the appropriate phase of cycle immediately following the push of the
button, and therefore:
n
there is limited
time to prepare for the crossing;
n
alignment must be
done with limited or no parallel traffic sounds;
3. The status of the pedestrian signal must
be determined.
In July, 2006, in view of the need to
adapt or revise our street-crossing strategies because of these new features,
our AER O&M Division approved a position
paper which states among other things that O&M specialists will provide consumers with information about how
actuated signals function and techniques for dealing with them, including
strategies to find and use pedestrian buttons and cross.
This means that O&M specialists
consider that “best practice” for teaching consumers to cross streets with
traffic signals means teaching strategies that are effective for crossing
modern signalized intersections, rather than the traditional strategies. O&M specialists who don’t follow best
practice and don’t teach effective, new strategies will have difficulty
defending themselves in case of a lawsuit, and will have to show why they chose
not to teach strategies that are considered best practice.
So, what strategies are considered
effective for crossing modern signalized intersections? I have recorded strategies on my website at www.sauerburger.org/dona/signals.htm
– I encourage you to browse and read the information and strategies, and share
your ideas and concerns. Hopefully we
can develop consensus and a body of knowledge for dealing with these issues, so
we can teach our consumers safe, effective techniques and provide them with the
up-to-date, accurate information they need in order to know how to cross.
Barlow, J.M., Bentzen,
B.L. and Bond, T. (2005) Blind pedestrians and the changing technology and
geometry of signalized intersections: Safety, orientation and independence. Journal of Visual Impairment
and Blindness. Vol 99, (10),587-598.
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