Going south on Van Ness Avenue just past 120th you will cross some railroad tracks and go over a slight crest in the street. On the right is a hidden entrance with a black wrought iron fence. Motorcycle cops frequently sit there with a radar gun. The speed limit is 35 but most people drive 45 to 50 in that area. Or sometimes the radar cop will be at the next intersection which is 128th Street. This occurs a several times a year and usually lasts three or four days. I suspect that several hundred tickets are written each time they do this.