I've often wondered why, as I'm driving down the highway in moderate traffic, everyone will begin to snarl up into a big traffic jam, sometimes forcing cars and trucks to a complete halt.
So you shrug and wonder what's going on...is there an accident ahead, or road construction, or the Partridge Family scurrying across six lanes? When traffic starts up again, you see absolutely no sign of anything that should have caused a delay.
Leave it to science to figure the whole thing out. Mathematicians from M.I.T. have found equations to describe what they call “phantom jams” or “jamitons.”
Think of it like the detonation waves from big explosion. A single driver, slowing down to adjust his radio or text his buddy, can cause a ripple effect, and based on the traffic density, things can pile up.
The next step would be for engineers to design roads that take traffic density into account, which would hopefully eliminate these "jamitons."
I'm just glad to know there's a real reason for this mess, even if it is still some person's fault.
Ghost Jams, via Freakonomics Blog