I don't flash my lights when I am on the interstate but I do on two lane roads. I don't do this to save people from tickets, I do it to warn people of road obstructions on the narrower roads around my home. If I flash my lights when a cop has pulled over somebody just over the crest of a hill, I am making the road safer. The ambulance service I worked for had a medic hurt because a guy slammed into the back of her unit because he was staring at the emergency lights.
There are also several small towns around my state who fund their entire city government via speeding tickets for very questionable offenses. One small town in the delta even ticketed one of our ambulances for going 7mph over the speed limit while patient loaded. In that town, I warn everyone I can!!
