If you were to stand in the middle of a busy intersection of pedestrian and vehicle traffic, you’d get significant impressions. Besides being concerned for your safety, you’d also notice it doesn’t always go well. The hair-raising screech of tires and squeal of brakes in a near miss of cross traffic. A motorcycle driver almost clips you with his daring zig-zag around another car. A pedestrian pushes through and almost knocks others over. Someone does lose grip and drops a package. Then there’s the motorist in a hurry and blazes right through a red light. You are almost run over as a bicycler whips by you. On top of all that, there’s the airplane overhead much too low for comfort. You haven’t even thought about a possible pick-pocket.