I was on a highway driving 5 over the 70 limit at night with a pack of cars in front. My V1 was set on the "big L" mode. I suddenly saw a bunch of cop cars in front with party lights on as a car fell into the ditch and was awaiting rescue. The V1 didn't go off until I was almost parallel to the cop cars. It then went off like a Christmas tree with the arrow pointing backwards (K or Ka) after I passed the cop cars and stayed that way for next mile or two. Why the V1 didn't give any warning on approach? This kind of detection performance doesn't inspire confidence.