This Simple Hack Convinces Drivers To Turn Off Their Engines While Idling In Traffic

Even if it’s just for two minutes, killing your engine can keep a ton of pollution out of the air. All it takes is getting people to actually think about it.

This Simple Hack Convinces Drivers To Turn Off Their Engines While Idling In Traffic
[Photo: Alex_Ishchenko/iStock]

Do you switch off your car’s engine when you’re waiting in traffic? What if you know you’ll be stuck for a while without moving, say when you’re at a railway crossing? Probably not, right? But if everyone turned off their engines while idling, pollution could be cut significantly, as would gas consumption. Using one weird social engineering trick, scientists have finally managed to get drivers to switch off.


By making a simple tweak to road signs, researchers at the University of East Anglia in the U.K. have made drivers more likely to obey them. The researchers zeroed in on a rail crossing that is closed around four times per hour, for around two minutes at a time. The crossing already displayed signs asking drivers to switch off their engines while idling, but only a fifth of drivers bothered to comply.

“We wanted to know how to persuade drivers to switch off their ignition in a situation where collectively they would, potentially, substantially pollute the atmosphere of a large number of residents and pedestrians,” head researcher Dr. Rose Meleady, of University of East Anglia School of Psychology, told the UEA Newsroom. “The destructive behavior examined in this study lasted for about two minutes, many times a day. Any reduction of this behavior, therefore, has clear benefits for all.”

[Photo: Toa55/iStock]

The researchers first tested a simple visual upgrade to the signs: adding a pair of watching eyes. The slightly creepy image boosted compliance, but only to 30%. So they decided to take it a step further, and literally instruct drivers to think of themselves. In the next iteration, the phrase “Think of yourself: When barriers are down, switch off your engine,” was added to the sign, along with the watchful eyes. Compliance under those combined commands went up to 50%.

Why does this work? It’s a form of surveillance, according to Meleady. When the drivers think of themselves, they are also watching themselves, and this perception of surveillance increases compliance dramatically. In a way, it’s similar to the double-dipping guacamole hack: If you put up a sign at a buffet asking people not to double dip, it doesn’t work. But if you put out two bowls of guacamole, one marked for single-dipper, and one for double-dippers, the double-dippers miraculously disappear. When people are forced to actually think about what they’re doing, they are more likely to change their behavior.

Idling vehicles are a big problem, especially if they gather in the same place, like at a rail crossing. “As well as wasting fuel,” the report noted, “[idling] creates an accumulation of particulate matter, carbon monoxide, and nitrogen dioxide in the local environment.” In the U.K., air pollution causes as many as 40,000 early deaths every year, and “no-idling” zones have been proposed in London. If a simple hack like this can help, it could be just about the cheapest and easiest way to reduce pollution there is.

About the author

Previously found writing at, Cult of Mac and Straight No filter.