Why have I seen 40+ semi's being escorted by police?

where were you when you saw that escort? There are quite a few things I can think of, what kind of escort it was ect. Was it typical city police officers or state police or the feds in black cars? did you see or hear any helicopters and how fast were they all driving? what did the semi's look like, any color schemes logos or symbols on the trailers etc?

I've always been interested when something like this happens. It could be a transport for a top secret project, and they're just moving it to a different location. My last guess would be human trafficking because it would attract too much attention with the police escorting etc. They could also be moving dangerous chemicals. Everything I'm saying is just speculation.

No helecopters, just once police car in front and another at the end. They weren't speeding, they were going the speed limit.