Interstate 55 N and S near 6 miles either side of Ruddock and Manchac Exits
My girlfriend and I have both been stopped on weekend mornings and been issued citations from airplanes. They work both directions of the highway at different times. The big white stripes on the road at random locations are how they time you. There’s no other device than a stopwatch. Big case for human error so fight it. We both got out of our tickets.