"An average walking speed of 40-ft/s is appropriate for typical groups of pedestrians. . . .At signalized intersections pedestrian crossings must be assigned an amount of effective green time based on average walking speed."
Now, a speed of 40 feet per second is approximately equivalent to 27.3 miles per hour. Do you run across the street at 27 mph? I didn't think so!
OK, OK, it's an error. It's supposed to say 4 feet per second, and the error has been noted by the publisher. But next time I see a fast signal, I'm going to wonder. . .