Last night my lovely wife and I drove up 93 from Massachusetts to the Great North Woods of New Hampshire.
One of the odd things we noticed was all the police out on the road. They were stopping tractor trailer rigs all over the place. By the fourth, it stuck out. By the sixth or seventh it was definitely a trend. Sometimes a single truck had two police cars checking it out.
Also noticed an unmarked government car on the road, with a guy talking on a handheld. By the way G-men, a car with a government license plate isn't really an unmarked car.
Traffic is pretty light north of Concord, so it's easy to notice what other vehicles are doing. All the police activity seemed out of place, as if they were actively looking for something, not just normal traffic stops.
There's all kinds of odd activity out there on the road. Most of the time, we never learn what's behind it.