Unravelling The Mysteries Of The Phantom Traffic Jam

We’ve all been there: happily driving down the motorway when a mysterious traffic jam rears its ugly head.

Forget the Loch Ness Monster. Forget the Abominable Snowman. The real mystery on this planet is the traffic jam... Well, the phantom traffic jam, to be precise (there’s nothing mysterious about the common-or-garden variety – every owner driver knows what those are…).

In response, in a heroic effort of detective determination, I’ve made like Sherlock, put on my tweediest deerstalker and solved, finally, the mother of all crypto conundrums: The Curious Case of the Phantom Traffic Jam.

Phantom Menace

First things first, what actually is this mysterious entity? You know when you’re happily driving on the motorway and suddenly the vehicles shudder to a snail’s pace, edge slowly forwards, grind to a halt and then, when things finally get moving again, there’s no reason for the hold up in sight? No accident, construction work or closed lanes? That’s a phantom traffic jam, the bane of owner drivers the world over. As if an explainable backlog wasn’t enough for us to have to deal with, we’re faced with uncaused – and therefore seemingly unnecessary ­– queues.

Just Jammin’

The folk in white coats have been putting their thinking caps on. Using all the resources of modern science, they’re getting to the bottom of this strange phenomenon. Researchers at MIT have even come up with a scientific – though frankly hilarious – word to explain it: the jamiton.

Jamitons are waves of deceleration that ripple through the traffic on a stretch of road. These pesky blighters are the cause of the problem. Basically, when one car slows for whatever reason (be it a slight irregularity in the road or a momentary lapse in concentration), the car behind it slows too, just a little, and the car behind that slows too, and so on, until the tiny slackening of pace is transformed into a full-on stop.

Call it a jamiton, a chain reaction or a very jammy Mexican Wave, the result is the same: your innocent owner driver is caught up in the stationary line, caused by that insignificant braking enacted further up the line. The typical phantom is anywhere from 100m to 1km long. That’s a substantial delay.

Jammy Dodgers

Can anything be done to avoid this troublesome situation from happening in the first place? To an extent, good driving discipline can help, such as staying equidistant between the cars ahead and behind. But this is standard practice for owner drivers, and scientists say that it doesn’t actually eliminate the possibility of a phantom jam anyway.

There are other possible alleviation methods, however. These include smooth, straight roads, which reduce the need for applying the brakes, and variable speed limits. By reducing the speed limit in areas prone to such queues, we could see a situation where drivers slow gradually, thereby disallowing a wave to form.

A Question of Queuing

Perhaps unique among the population, the subject of traffic jams is very dear to the owner drivers’ heart. From the point of view of the courier industry, they eat up extra fuel, reduce the number of deliveries that we can achieve in a day, and simply drive a driver round the bend! Knowing the science behind the phantom traffic jam might not make them disappear, but it at least gives us a greater understanding of what’s going on as we sit in line, drumming our fingers on the wheel.

So, that’s it. Case closed!

Author Plate

Norman Dulwich is a correspondent for Courier Exchange, the world's largest neutral trading hub for same day owner driver jobs in the express freight exchange industry. Over 5,000 member companies are networked together through the Exchange to fill empty capacity, get new clients and form long-lasting business relationships.

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