State Highway 47 near just north of town
Cops sit in the dark sometimes on a private driveway sometimes on the shoulder zapping people as they go by. The speed changed from 55 to 50 as you come south into town.
They are also on the south of town on 7th Avenue and also sit on the shoulder in the dark.
I have never seen any at night or during the day though. But I bet they are there just not sitting still.