Think about it, LIDAR (laser) cannot be used moving, and is currently the top dog in speed detection. As others said before, the air pressure blah blah is certified BS. Police will ticket you on their observation or perception of your speed, and judges just don't care- they trust the cop over you because it = revenuse for the city/county/state. I was told once by a police officer that had been on the job approximately 2 weeks he could visually tell I was speeding when I went past and that I must have been because he had to drive 75mph to catch up. I told him, if I passed him in a 35mph zone and he was sitting, and I accelerated to 55 at the sign about 2 blocks later, basic physics says h would need to go a hell of a lot faster than 55 to catch up. Sadly this logic held no water in the rediculous kangaroo court, and I had to pay. Traffic tickets are no longer about enforcing the law, they are about revenue generation for municipalities and judges will not disrupt the system. Having a V-1 myself, I am sure the cop didn't have his radar on, until he turned around and tried to light you up, because he saw you speeding, but wanted hard evidence to write you up. You got lucky dude.