"In certain counties, the sheriffs departments are much more active on the interstates than SHP."
True for Northampton County. Everytime I'm on I-95 in Northampton County, the Sheriffs Department have people pulled over on both sides of the road. Ticket Trap. Worse is when construction is going on there and the Deputies love to tuck in between the heavy machinery to pull speeders because in NC, penalties for speeding in a road construction/repair zone is above the normal penalties for speeding.