The Slingshot Effect

Reader Brad writes in with a query:

I wondered if you could indulge me by trying to answer a question that has long puzzled me; I drive mostly on rural roads, and not infrequently must follow a slower car until the opportunity to pass occurs. Often, as I pass I notice the other car speeding up slightly — at least 5–8 mph it seems over its previous speed; almost a magnetic or slingshot effect. I have even noticed that at times I do it myself, involuntarily, as I am being passed! Is this a recognized phenomenon with its own name?

Has anyone else experienced this? One answer may be that the driver being passed has simply lost track of his speed, and being passed suddenly alerts them that they may be driving slowly; speeding up may be a sort of panic response. Another answer is that the sight of being passes awakens some competitive impulse, a version of the “territorial defense” mechanism theorized by Barry Ruback — even if the territory is abstract road space, and the person passing in this case is actually not competing for the same resource, given that they’re in the opposing lane. Or maybe they’re just playing chicken.

In Traffic I note a strange, somewhat related version of this phenomenon, which I call “passive-aggressive passing” — someone bullies you out of the left-lane, you dutifully get over, and they then pull in front of you, and drive slower than they were when they were on your tail. It’s as if all they wanted was to get you to pull over.

But I have no doubt there may be less than noble motives at work in these cases. I myself am guilty of doing something like the following: I will be driving along (in say the middle lane) when I notice someone coming at a high speed on the right side. It seems as if their intent is to cut in front of me, in the small space I have left between myself and the vehicle in front of me. Annoyed by this person’s behavior — the idea that they may pass close to me at a high speed, perhaps forcing me to brake — I have at times slightly accelerated, so that I move closer to the vehicle that is ahead of them in their own lane. The result is that they must hit the brakes, and try something else.

Immature? Perhaps. Or maybe it’s simply pro-social altruistic punishmenthomo reciprocans.

This entry was posted on Tuesday, June 16th, 2009 at 8:10 am and is filed under Traffic Psychology. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

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June 2009

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