In the Washington, D.C. suburb of Arlington County, Va., the exit from Washington Boulevard to Route 50 had always been a trouble spot. County police say they usually have more collisions there than any other intersection in the county, and almost all of them are rear-enders.

Police have typically put up electronic signs that display messages urging drivers to be cautious, with phrases like "High Accident Area Ahead" and "Maintain A Safe Following Distance."

But this summer, the Arlington County Police Department went back to the basics and displayed a message so ridiculously simple it almost seemed laughable: "Don't Hit The Car In Front Of You."

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The sign was first reported by the local news website ARLnow, whose commenters poked fun at it and suggested it was a waste of money to say something so obvious. Typical of the response was one commenter, who suggested Arlington County could extend the effort further with signs that say "Do Not Commit Crimes" in dangerous areas.

But Dustin Sternbeck, a public information officer for the Arlington County Police Department, says the sign may have actually helped reduce collisions substantially. In the six weeks before the sign went up, there were five accidents at the intersection. In the 10 weeks after there, there was one. Of course, correlation doesn't mean causation. But the results may be worth paying attention to nonetheless.

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The idea, Sternbeck said, was "to simplify the message as much as possible." As a side benefit, the humor of the sign also generated some buzz, which may have gotten residents thinking more about driving safely.

"It was kind of eye opening," Sternbeck says. "We got people to pay attention. It wasn't something we sat down and planned out (but) now we see the positive impact it's had. It's an approach we can try in the future."

The move is the latest in a string of bizarre news stories about seemingly simple government interventions paying big dividends.

Earlier this summer, police in the Boston area put a cardboard cutout of a cop in the corner of a subway station to deter bike thefts. It worked so well they're considering expanding the program in hopes of reducing fare evasion.

Meanwhile, transportation officials in South Florida are experimenting with an optical illusion that could make motorists drive more slowly. The hope is that horizontal lines painted at gradually closer intervals on the road will make drivers ease off the gas, since they'll feel like they're gaining speed even when they're not.