Illegal speed trap?

I know some states have illegal speed trap rules saying a speed trap can't be set up within X feet of a speed limit change. Does NC have such a law? They set up a speed trap (using instant on K, I didn't get caught, but I would have if I didn't see him pull someone over earlier. I was the only car around so when he did hit me, doing the speed limit, it was only 2/10 of a mile away and I got a full on K blast, then nothing after driving a little less than 2/10 of a mile at 35mph) in my town (Town of Davidson police) inside a 35 zone...10 feet from where it was 55mph. Where I observed a cop who was off duty and driving home in a red Corvette doing 65mph btw.
Richard

That pisses me off also. On I 71 one time I followed a State Trooper. I was right behind him the whole time doing 80mph. He must have been going 85mph. My father was in the car with me going nuts yelling at me to slow down. I told him "dad he will not pull me over look at him he is flying, why can he break the law?" This went on for about 65 miles. This is a true story. Would I do it again? NO! I was young, naive, and cocky at that time.