to determine there is a crossable gap in approaching traffic
We had been talking about crossing in Situations of Confidence whenever you know it's "clear to cross" because you hear/(see) nothing coming.
To summarize, the skills that our students need in order to know the approaching traffic is far and/or slow enough to allow them time to cross are:
** Now we're going to talk about crossing in situations where you can see traffic approaching from a distance.
You might be asking yourself
I'll answer the first question first.
Many people with visual impairments such as retinitis pigmentosa and macular degeneration can see traffic quite far away.
In these situations, they may want to cross when they determine that the traffic is far and/or slow enough that they can cross
-- that is, when the "time-to-arrival" of all the approaching vehicles provides enough time to cross.
- "How on earth would our students with visual impairments ever be able to see traffic in the distance?
- And why the heck would anyone cross when they know that vehicles are approaching?"
For example, Lorraine Evensen had albinism and undoubtedly could see the headlights of approaching cars more than 2 blocks away at the crossing (shown to the right) where she and her husband Dick were killed.
However, she apparently misjudged how close and fast those cars were.
We want to make sure that our students do not make the same mistake, and think there is time to cross when there actually isn't.
Now the second question -- why would anyone cross when they know that vehicles are approaching?
The answer is that this is how most people cross.
If they didn't, they would be very limited because there are many situations where there are always approaching vehicles visible in the distance, providing no "all clear" opportunities for crossing.
So most people are very familiar with the task of judging whether the approaching vehicles are far/slow enough to allow them time to cross.
In fact, the accuracy of this judgment is something that has been studied for many years.
It's a skill that is necessary for travel in many areas; pedestrians and drivers who want to cross busy streets will watch the approaching traffic until they think there is a gap long enough to cross.
They don't do it by counting seconds or using a stopwatch, they've learned to do it naturally and instinctually, and their lives often depend on how well they can do it.
Many of our students can learn to do it accurately, and they should be able to do it naturally and instinctually. I'll share a story with you about developing what I call the "WHOA!" feeling:
When doing research with Gene Bourquin and Rob Wall Emerson, my job was to watch the approaching vehicles and tell Gene the moment that they were
5 seconds away, so that he could start walking into their path (yes, that does sound crazy, doesn't it? But we learned a LOT when drivers thought they would hit him if they didn't stop!).
Anyway, I took about 5 minutes to train myself to make this judgment accurately, and we started.
At first I made the judgment by consciously projecting the path of the vehicle and imagining Gene walking forward to determine when he should start so that they would be on a collision path.
But after about half an hour, I didn't have to consciously do anything! All I had to do was watch those vehicles approaching until I got this physical "WHOA!" feeling in my gut, a feeling that said "It's too late, if I start to cross now and the vehicle doesn't slow down, it could hit me!" That "WHOA!" feeling turned out to be as accurate as my conscious visioning and projecting had been.
This gut feeling of "WHOA! It's too late to start crossing!" can be the goal of this training for our students.
And THAT is what the next few pages will cover!
- Be able to naturally and instinctually determine if the time-to-arrival of the approaching traffic will be long enough to cross; and
- if crossing a two-way street, be able to make this determination by glancing / scanning.
Can people make this judgment (determine there is a crossable gap in approaching traffic) by using their hearing?
Well, yes and no -- primarily NO!
Research has shown that people can learn to determine from the sound of an approaching vehicle how much time will pass before it arrives, BUT
using this skill may be UNRELIABLE for determining if you have enough time to cross!
The reason it is unreliable is that the sounds of one approaching vehicle can mask the sound of other vehicles.
So even though people can determine that the vehicle they hear will not arrive before they finish crossing, the sound of that vehicle may mask the sound of other vehicles
that will arrive sooner.
I therefore believe that even though students should be taught to use their hearing to reliably determine when it is clear to cross ("cross when quiet") in Situations of Confidence,
it is inadvisable to train students to use their hearing to judge
whether they have enough time to cross when they can hear that vehicles are approaching.
For these reasons, the following pages will focus only on teaching people who can use their vision to determine whether there is still time to cross when they can see that vehicles are approaching.