For the past month there has been construction in an area in my town and for that period of time they put up and electronic sign stating which roads to take. You know the big orange signs *duh*(construction has wrapped up and the sign has been taken down). Anyway, I was curious why they put a K Band radar unit on the sign. Everytime I passed the sign my 955 went off. The sign was not there to detect speed it just stated the warning of construction. My question is why does the sign emit K band radar. Also, the cops in my town use Ka exclusively why didnt they use that?