Derry Police can be found in this area between Rt 981 and Rt 217 any time of the day or night. Just past the school admin building and midway around the lake. speed limit goes from 30 to 25 and they hand out dozens of tickets here daily. I might add that it’s a school zone so make sure you go 15 mph during thr posted times or you’re up for a 500 buck ticket plus costs.