If you're someone who runs in place while waiting for the light to change, your psychological profile indicates that you're a narcissist who likes the attention and have a pathological need to be respected in your peer group, despite evidence that nobody gives a crap.
In other words, you're a douche.
Running in place is about as useless as contributing to a John Kerry presidential campaign. Not only do you look like a tool, you also attract the ire and contempt of drivers who feel the holier-than-thou vibe coming off your sweaty body even from the road at 35MPH.
It's the purposeful yet casual place-jog that says, "Not only am I healthier than you, my whole life is lived in utter perfection and unity with the world around me, and I am so overjoyed at my awesomeness that my body won't let me stop moving!"
It's respected by exactly zero people. Except for other runners, who don't count in this case because you're all in a global health-measuring contest, so insecure that you must show the world that you've got legs that won't quit. You're the kind of person who not only takes the stairs instead of the elevator, you take them two at a time, and then you tell everyone in your office that you take the stairs, and you let everyone know how much healthier it is to take the stairs. You tell everyone how amazing you feel when you take the stairs (read: how superior you feel to the elevator-takers). You eat Power bars and shit roses, and probably donated money to the Make-A-Wish Foundation only so you could tell people how you help children overcome autism. What a turd.
I've heard the excuses. If you stop running the lactic acid starts to build up in your muscles! Gee, stopping for thirty seconds while the light changes really throws your muscles out of whack, huh? Well if you weren't such a douche maybe you could handle it. Stopping takes me out of my rhythm. Really? How hard is it to get back into rhythm? Let's see, start jogging. There, your rhythm's back, jerk. I gotta keep my heart rate up! Idiot, it's not Speed. You're not going to blow up the retarded bus that is your heart if you stop at the intersection.
You know what else sucks about your stupid intersection treading? You look like you're going to cross the street at any moment. Oncoming drivers, or people trying to turn may be thrown off by what looks to them like a douchebag about to cross the street; what started out as a pseudo-health buzz becomes a safety hazard.
Seriously, douche, I really can't stand you. Go run in place where people can't see you, like a water-robics class at the ghetto YMCA, or your bedroom (where you can stare at your KISS concert poster and listen to Vanilla Ice).
Or better yet, why don't you just run out into traffic and save us all the annoyance.