Our points are complementary. The errors of the speedometer and the error of speed gun may add up. The police will take off 5 km/h on the recorded speed, when

Our points are complementary. The errors of the speedometer and the error of speed gun may add up. The police will take off 5 km/h on the recorded speed, when editing the fine. That's supposed to cover the margin for error. You're out of luck if your car meter is 5 km/h off and you were trying to drive at the speed limit.