Between 125 North exit from 93 and Andover street, cops use Ka band and sit along the northbound shoulder catching people as they pass the light for ballardvale st. I have see the police activity only after dusk. I have also seen instances where there will be another radar trap on northbound 125 about a mile or two down the road using Ka band to catch people at the same time, going the same direction, on the same road.