You are in a car, waiting at a red light at a major intersection (the street is wide). As the "Don't walk" sign begins to flash, some adventurous pedestrians break out in a run, launching into the crosswalk and across the street. As they crest the half-way point, a calm overtakes them. Perhaps they realize they are going to make it, so they don't have to try so hard. On the other hand, perhaps they realize that life just isn't worth all this fuss, so they lay their fate down on 8th Avenue (for example), come what may. In any case, they are still in the crosswalk when the light turns green, blocking your path.
Having watched this phenomenon time and again, I have come to the conclusion that it is all an act. The run is not really a run, but rather a lethargic jog that that takes them across the street at roughly the speed a walk would. The jog is not for their benefit, not a life-preserving measure. Rather, it is a show put on for you, the motorist, who knows the pedestrian will not make it before the light turns green, forcing you to choose between vehicular manslaughter and delaying departure by a few very precious seconds. Look, the jogging pedestrians say, we're trying!
The other day I found myself approaching an intersection on foot as the "Don't walk" sign began to flash. I thrust myself into the street thinking, I can make it if I run! As I neared the curb, the urgency lessened and my gait slowed, and I was a few steps away from the curb when the light changed. I never felt as though I was in any danger of being run over. In fact, I didn't regard the motorists at all. Getting to the other side a few seconds late was good enough for me, and frankly, I was the only one involved.