If you've spent any time driving across the United States, surely you've seen the signs: "SPEED ENFORCED BY AIRCRAFT." What, exactly, does that mean? How do they track speed with aircraft? Surprisingly, the technology is pretty old school.
Why the mystery? Different states patrol speeders from the sky and some states almost never do it. In areas where the signs are present, most motorists never see the planes or helicopters monitoring them, which makes it all seem like a ruse. But it's for real, alright. And if you're not careful, speed enforcing aircraft technology could cost you.
No, The Aircraft Doesn't Land and Issue Tickets
Yes, this appears to be an actual misconception. In 2016, Northern California news radio station KQED ran a piece about this after a listener asked the station to investigate.
Listener Aaron Perry-Zucker said the signs "didn't seem believable" because after all, he's never seen an aircraft issue a ticket. So what gives? As journalist Kelly O'Mara reports, "The officers in the air don’t actually land and issue tickets. That might cause a traffic accident."
So what actually happens? Once you've been caught speeding, officers in the sky radio down to an officer on the ground who pulls you over. Since it's nearly impossible to make out license plates numbers from that far up, the officers rely on detailed descriptions of the vehicle instead. Doesn't this lead to a lot of contested tickets? Not according to Ontario Provincial Police Sgt. Peter Leon (Ontario has nearly identical procedures as California as several other states in this regard.) “Usually the plane will stay with the vehicle until they know that it’s been stopped,” Leon says.
You're Not Always Pulled Over
The process of getting a speeding ticket from the sky isn't always so cut-and-dry. Sometimes, a speeder is ticketed but can't be pulled over for some reason - like they were going way too fast (an extreme example of that in the video above). In one example out of California, a motorcyclist was caught on camera from the sky racing through a neighborhood at high speeds. About 20 minutes later, an officer knocked on his door and issued him a ticket, much to his surprise.
The Aircraft Doesn't Use Radar
Let's clear up another misconception: unlike their ground counterparts, the aircraft patrols do not use RADAR or the more precise, laser-based LIDAR to detect speeders.
There are a few other methods to determine from the sky if a motorist is speeding, and they're actually pretty old-fashioned. KQED reports two officers are present in a helicopter when patrolling the Bay Area, and both simply use their eyes to determine, initially, if someone has a lead foot. After that, it's simply a matter of flying low above the car and matching its speed.
They also clock speed by timing how fast vehicles get from one point to another. Ever notice those white, perpendicular lines painted on the side of the highway? Officers on patrol in the sky use those to clock speeders using a charmingly old-fashioned piece of tech: a stopwatch.
If the weather's bad, don't worry: they're not up there. In northwest Missouri, Troop H of the State Highway Patrol only sends up an officer in a Cessna when it's not cloudy, rainy, or snowing. Other states admit it's not a daily operation: officials in Iowa, for example, told Slate in 2013 it's a weekly concern. Ohio said it had "15 uniformed officer-pilots, two American Eurocopter turbine-powered helicopters, and 14 Cessna airplanes" at its disposal for such a task, but wouldn't spill the beans about how often they patrol.