One person vs. Traffic Waves

Thanks to reddit, I read this article today about how one person can change traffic waves. This is a topic I wind up thinking about a lot as I sit in traffic. Compared to most people (if you believe the news reports), my commute isn’t too terribly bad (i.e. mine is less than 30 minutes most days), but reading this article did make me think.

Traffic waves are what happens when there is a slow down for some reason in the flow of traffic. The cause could be an accident, a glare from the sun that blinds people, or just about anything that causes traffic to slow down. As people slow down, the drivers behind them also have to slow down. As the first drivers pass the “distraction” that caused them to slow down, they begin to speed up. But this speed up does not get propagated to the other drivers right away, so the drivers further back in the pack are still going slow (and thus causing the drivers behind them to slow down). The result is a “standing wave” where the cars slow down. As long as there are more cars heading to wave, the wave will persist (assuming the original distraction is gone), once the rate of cars coming towards the wave slows, the wave breaks down and disappears.

Anyways… The article has an interesting idea of using Police patrol cars to help break up the wave by having them in the traffic (several miles before the slowdown) driving at a “slower” speed than the normal traffic flow. Because people are not likely to drive fast past a cop, this effectively slows the rate of cars flowing into the wave, which helps to break it up. Its a really interesting idea, and I think it could really work.

One thing that I’m not so sure about is the authors assertion that he could affect the same thing by driving at a steady rate (i.e. avoiding stop-and-go and trying to keep a good buffer distance between himself and the car in front of him). His idea is that once he does this it encourages the drivers behind him to do the same thing. I’m not sure I agree with this, I see a lot of impatient drivers on a daily basis. Maybe its just here in Atlanta, but if there’s a half a car length in front of you, and your lane is moving, someone is going to try and get in there.

Having said that, I do like the spirit of the idea and I’m going to try it out next week as I drive in traffic. Who knows, maybe a few other people will read that article and try the same thing. Anything that keeps the traffic moving is a good thing in my book.