Traffic that grinds to a halt and then restarts for no apparent reason is one of the biggest causes of frustration for drivers.
You’re not kidding. As a grizzled veteran of both the I-287 and I-80 commutes in New Jersey and the I-270 commute in Maryland, I can’t tell you how many times I’ve been in situations where the traffic just comes to a standstill, and no sign of an accident or streaker in sight. It’s enough to put a person over the edge.
The mathematical theory behind these so-called “shockwave” jams was developed more than 15 years ago using models that show jams appear from nowhere on roads carrying their maximum capacity of free-flowing traffic – typically triggered by a single driver slowing down.
Some Japanese scientists have moved beyond simulations and were able to recreate this in a live experiment.
They asked drivers to cruise steadily at 30 kilometres per hour, and at first the traffic moved freely. But small fluctuations soon appeared in distances between cars, breaking down the free flow, until finally a cluster of several vehicles was forced to stop completely for a moment.
Of course, I could have predicted exactly this scenario. Heck, I’ve even seen it when a marching band was leaving the field after their halftime show.
I’m glad I commute on the train now.