Air war: Speed limit really is enforced by planes

With spring in full bloom, a Charlottesvillian's thoughts often turn to day-tripping by car. If you've ever considered those "Speed Limit Enforced by Aircraft" signs to be one of the heartiest haha's on America's highways, you may be surprised to learn that Virginia State Police really do enforce the speed limit from thousands of feet in the air. Anyway, aerial enforcement (as it's known in the police game) is very real. Virginia has been monitoring motorists from the air since July of 2000.

Here's how it works. Two officers in a Cessna 182 (Virginia does not use helicopters for speed limit enforcement) will fly back and forth over a pre-determined section of highway that has been painted with start and finish lines half-a-mile apart.

There are 101 such "fixed course sites" laid out on all the state's major highways, including our own beloved I-64. When a suspected speeder enters the course, the officers in the sky boot up their VASCAR system (Visual Average Speed Computer and Recorder) to determine the speed of the vehicle.

Lieutenant Nick Saunders is a 16-year veteran with the Virginia State Police Aviation Unit.

"VASCAR's not much more than a glorified stopwatch," says Saunders, "but it's fairer to motorists than radar. Radar records your speed instantaneously and doesn't take into account the fact that you could be decelerating. But VASCAR takes the average speed over a certain distance."

When a vehicle is caught speeding, the officer in the plane radios to another unit on the ground which actually makes the stop.

While there may be more to it than just the ominous signage, don't go thinking you're about to get nabbed by a cop in a Cessna. The odds are against that ever happening.

Aside from the fact that you never go more than five miles over the speed limit anyway (wink, wink), aerial enforcement is incredibly pricey. The State Police reckons the cost at keeping a fixed-wing aircraft on patrol to be about $70 an hour for fuel and maintenance. If you figure that most aerial enforcement patrols last about four hours, the state has already spent hundreds of extra dollars before collecting even a dime in fines.

Not only is it expensive, but Virginia does not have a fleet of Cessnas at its disposal. The Aviation Unit has only one plane available at each of its four stations in Manassas, Abingdon, Lynchburg, and Richmond.

"It's more expensive, of course," Saunders says, "and it's more labor intensive. But it's just one tool among many that's available to us."

Saunders admits that the real punch comes from the highway signs. "Hopefully the signs will act as a deterrence. If a motorist happens to read the sign, glance up and see an aircraft in the vicinity, even if it's not ours, it tends to cause closer attention to their driving. That's a good thing. There are a lot of ways to get the public's attention. Sometimes a gentle reminder is just as effective," he says.

It should be noted that several studies– including a 1984 NTSB report to Congress– have shown that aggressively enforcing speed limits does not appreciably reduce highway speeding or accidents. The real reason for nabbing drivers who break the speed limit (besides pumping dollars into law enforcement, which can be a real motive for some departments) is to create a police presence on the road.

Fact is, just seeing an officer at the side of the highway with lights flashing does more to encourage safe driving than any number of speeding tickets. Perhaps an inexpensive mannequin in a squad car perched at the side of the road though derided by many in law enforcement may actually do more good than the Eye in the Sky.