It is estimated that in 2014 that there were over 41,000,000 speeding tickets issued in the USA and that over 25% of these were issued in error.
The most common errors include shadowing, RFI inference, cosine angle error, mechanical interference and devices that are out of calibration.
But out of these 41,000,000 speeding tickets only 5% challenged their citation in court.
And out of this 5% less than .05% beat their ticket or have it dismissed.
Why? Because they were not prepared!
The radar gun or lidar gun the police officer used to issue you your speeding ticket is a scientific instrument and because of this the officer must be certified and by law, must follow certain requirements.