Night. Pitch black because of no street lights. Leaving small intersection. Passing a semi-truck that was under the speed limit in the left passing lane. Returned to flow-of-traffic speed. Saw lights in mirror. Nice cop, but could care less that I was passing a truck before reducing speed. Gave me instructions to call a number that would help me to keep points off my record. This was just about the fine as income. There was nothing about need for safety. I was staying with the flow of traffic which was slightly above the expected speed, but not fast. Obstructing traffic to the flow is more of a danger than most things, especially at night. This was a issue of the “letter of the law” versus the “practicality of the law”.