Procedure
to Develop Judgment of the Detection of Traffic
Teaches people to be able to recognize situations where they can not detect traffic
well enough to know if there is a sufficient gap to cross.
1) Go to an appropriate intersection that
has frequent but intermittent traffic (that is, traffic with sufficient gaps).
2) Have the students determine the street’s
width and understand how much time they need to cross (for strategies to teach
these skills, see Program to Teach Concepts and Risk Analysis
for Uncontrolled Crossings).
3) Have the students try to judge whether
they can hear or see the traffic well enough to know when it is clear enough to
cross or, conversely, whether the vehicles are appearing without enough
warning. Allow them as much time as they
need to observe and listen, and perhaps prompt them with questions about the
traffic such as “if you had started to cross just before you heard/saw that car
(that is, when it was still quiet / you didn’t realize something was coming),
would you have finished your crossing before it passed, or would it have to
slow down to avoid hitting you? Listen
to /watch the approaching traffic as long as you need, and tell me if you think
you can hear/see all vehicles here well enough to know you have time to cross,
or if you think some of them aren’t audible / visible until they are too
close.”
NOTE: Students should be judging conditions when it
is quiet (or, if they are using vision, when the visibility is good). Many students who rely on hearing to cross
are unaware of the presence of noise and how much it impacts their ability to
hear approaching traffic – if they try to draw conclusions about how well they
hear traffic when there is masking noise, encourage them to notice that there
is a noise present (an airplane, receding car, lawnmower, etc.), and notice the
effect that the noise has on their ability to hear the approaching traffic.
4) Use the TMAD to
provide them with feedback to help them improve their judgment.
NOTE: Many students are able to understand the
effect of noise on their ability to hear approaching traffic by simply noticing
how close the vehicles can get before they are heard when there is a masking
sound from receding vehicles or other noise.
For students have difficulty understanding this, it can be effective to
use the TMAD to compare the detection time of vehicles that approach when it is
quiet to those that approach when it is noisy.
5) Repeat this procedure of providing
feedback and testing their judgment under a variety of conditions, until they
can accurately judge when the conditions are such that they can recognize when
it is clear to cross, and when they cannot.
Conditions in which their judgment is tested should include those in
which they are able to hear or see the traffic well enough, and those where
they cannot, to ensure they can tell the difference.
Note
that the conditions (masking sounds, lighting conditions, etc.) must remain
relatively steady long enough to test whether the student judged the situation
accurately.
To
test a variety of conditions, you can go to various intersections, or vary the
conditions at one intersection (for example with various masking sounds, or
objects to block the sound or the view).
NOTE: “Teaching and
Assessing Judgment for Crossing Streets Where There Is No Traffic Control” is a
two-hour video by Dona Sauerburger demonstrating the use of this procedure with
a blind woman, and the use of the TMAD to help a woman with a visual impairment
to learn when her vision is more reliable than her hearing for determining gaps
and vice versa.
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