Anywhere on US 425 or on US 65 in Clayton.
Location varies but they are using handheld LIDAR unit that captures speed and phot, then they send you a ticket in the mail. And it’s not cheap : $180-$225 range. State law requires signs to be posted from 250-500 feet of where units are operating. This happens sometimes, other times they are not clearly marked. Just be advised that if you are speeding through Clayton, expect to get a letter in the mail.