So how can we recognize Situations of Uncertainty?
** The only way to determine if you are in a Situation of Uncertainty is to observe and analyze how much warning time you have of the approaching traffic in that situation and make sure it is longer than your crossing time
("warning times" of approaching vehicles is the time from when you first think you hear /see them until they arrive).
** Other than observing whether the warning times of approaching vecicles are longer than your crossing time, there are no rules or guidelines that reliably predict whether you are in a Situation of Uncertainty.
Even rules that seem intuitive, such as "it is safe to cross when it is quiet IF the street is narrow and visible for a long distance and the traffic is slow," are NOT RELIABLE!
I will illustrate this with a story. Many years ago, I was looking for a street-crossing situation for my client to analyze, and I wanted it to be a Situation of Confidence where she could hear the approaching vehicles with plenty of warning.
I chose the crossing in the photo to the left. It seemed perfect!
The road was narrow (only 2 lanes), the speed and traffic volume were low, and there was nothing blocking the sound of traffic -- I could see the traffic approaching from quite a distance.
So I brought her there for our session. As she listened to the traffic to figure out how wide the street is, she quietly said, "I can't hear the cars well enough here to know if it's clear to cross."
That session was videotaped, and I still chuckle when I see my face showing the shock and disbelief that I felt when she said that.
I thought, "This can't be true!"
So I listened, and sure enough -- she was right! I could see the cars coming but neither of us could hear them until they were about 5 seconds away.
Anyway, if you can't take my word for it, find out for yourself -- go to the next page and see how well you can predict which of the situations in the "Uncertainty Prediction Challenge" show a Situation of Uncertainty for gap judgment.