If you’re driving somewhere this Labor Day weekend, there’s a good chance you’ll run into a “phantom traffic jam” — a highway slowdown for no apparent reason.  

KYW’s Mike DeNardo reports a Temple University researcher has studied this phenomenon.

It’s no one’s fault, says Temple math professor Benjamin Seibold.  At high traffic volumes, any  small disturbance in traffic flow can trigger a ripple-effect of drivers hitting the brakes, creating what he calls a “phantom traffic jam”:

“There’s no outside reason for those traffic jams.  There’s no obstacle on the road.  There’s no car in the breakdown lane.  They’re an instability in the traffic flow, so they can occur without any visible reasons.”

And the wave can travel backward for miles, and spawn successive waves. 

Seibold says individual drivers can mitigate the effects by driving less aggressively and leaving a little more distance from the car in front — assuming another driver doesn’t cut into that space you just created.

(File photo by KYW’s John Ostapkovich)