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.

Return to Home page