Like hell they do! The truck speed limit in California is 55 mph. They pass me when Im doing 70. I have never seen a semi pulled over for speeding. NEVER!
Either have I!! We do have an interior checkpoint/truck scales around the Camp Pendleton area so they ARE checked there.
They do stop them there for weight and other vehicle code checks, but I was refering to a speed issue.
Good point about the checks though. Still, if a truck only operates within LA or another suburban area, there are no check points. Generally the truck stop areas are outside the major metropolitan centers.