You live in a city. You try to walk across a street. There's traffic. You press the button and...nothing happens. It's as if it was a placebo. Boring.
So this German student has done the world a great favour by designing the perfect time-waster. Some of the cool features include a countdown timer showing how long the traffic lights are green (or red) and the fact it's multiplayer, pitting you against someone on the other side of the street.
It's probably far too dangerous, and expensive, to ever be adopted for widespread use, but it'd be nice to see a few installed around Köln for next year's Gamescom!