Chelsea PD almost nightly after midnight will sit in the grass just after the funeral home on your left as you are leaving Chelsea going north on 52. The speed limit changes to 45 there and they are pointed southbound facing northbound traffic. I am assuming they are there to catch those that do not slow to 45 from 55, since it turns 55 right after the trap. But I have also seen those pulled over who go too fast in the 45.