Those signs you see along the highway warning you about airplanes monitoring your speed aren't just for show.
Ontario Provincial Police are up in the sky more than 200 times a year. Friday morning they were patrolling Highway 401 near Cornwall.
From nearly 3,000 feet in the air the cars look like ants, but it's even clearer when one is going way above the posted speed limit.
Sgt. Hans Schirmer has been with the OPP Aviation Services for six years and said there are benefits to patrolling with airplanes.
"There's a big advantage to having that bird's eye perspective of what's going on on the highway," said Sgt. Schirmer. "We can literally look at hundreds of vehicles at any one given time and certainly pick out those motorists who are driving more quickly then the rest."
Another one of those benefits is being able to nab multiple speeders at once.
"We have numerous interceptors that we're using at any given time," he said, of the number of police cars on the road below. "When we do make that observation of in this case three vehicles driving all well above the posted speed limit, we have the capability of stopping all those motorists at the same time."
An officer in the plane times how long it takes for a car to pass between two yellow markers. They use a special device that calculates the speed of the vehicle.
If the vehicle is going too fast, the officer will radio down to waiting police cruisers which will intercept and ticket the speeders.
Over a three hour period Friday morning, police caught 15 people going at least 30 km over the posted limit. The car traveling the fastest was clocked at 144 km/h.