A truck driver was on a highway where the speed limit is 65mph. At 9:10 am a traffic control camera clocked the velocity of the truck at 60mph and 9:15 am a second camera located 8 miles down the road clocked the velocity of this truck at 65mph. In a couple days the truck driver received a speeding ticket and was surprised. "how did they know I drove above the speed limit?"
At some point what was the speed of the truck on the highway?