Why Do Traffic Jams Happen for No Reason?

You're stuck in traffic. Then the road clears and there's no crash, no roadworks, nothing. So where did the jam go? It moved. Backwards, against the traffic, at about the speed of a cyclist. And you drove straight through it. In this video we look at phantom traffic jams: the Japanese ring experiment that created a jam from nothing, the 1967 Ohio aerial photographs, why one tiny brake tap can grow into a wave, and what actually helps, from ramp metering to smarter cruise control. Next time the road stops for no reason, leave a little more space. Subscribe to HOW COME for the hidden reasons behind everyday life. #TrafficJam #HowCome #Explained