You’ve just made your way out of a really frustrating and time-consuming traffic jam, and you’re looking around to find what caused it. Maybe an accident or a broken-down vehicle? A herd of runaway zoo animals? But no, there’s nothing there to explain the hold-up. So what happened?
The latest episode of RiAus’s A Week in Science investigates the phenomenon of ‘the phantom traffic jam’ and the mathematical models that scientists use to explain it. One particular study by a team of Japanese researchers involved watching a group of drivers moving around a track at a constant speed. All it took to cause problems in the flow of traffic was one car to very slightly slow down, which had a significant flow-on effect from car to car to car, eventually causing a whole lot of cars on the track to clump together. In a real-world scenario with very heavy traffic, this flow-on effect could theoretically last forever, if the roads remain at capacity.
Watch the video above to find out more about the science behind these ‘invisible waves of congestion’ that plague our everyday lives.