| You are right, a lot of different factors can influence a radar reading, that is not in dispute. However, from my experience, having seen several things effect the radar unit, the only one I have seen that will make a slight (4-8mph) difference is the cosine effect, which is precisely why we try to be as close to head on as possible. Before we pull someone over for speeding, we are trained to estimate the speed before turning on the radar. If I see a car coming towards me in a 30 mph zone and I estimate it at 50 mph, turn on my radar, and it shows 53 mph, then I have no reason to think it is not correct. Then, I see the 53 mph, speeding driver sees me, and hits his brakes. I react as quickly as I can, but I lock the radar at 46 mph as he is slowing down. I am still going to write the ticket for 53 mph because that is the speed he was going, and I will testify under oath the car was going 53 mph. |