Comment by notch656a

You can but at least in the last state I lived, a cop's guesstimation is accepted (they count in their head or watch and count the lines or something, or that's the theory). In practice if the cop used an uncalibrated speed gun or whatever he'll always just say it was his guesstimation and precedent holds that the preponderance of the evidence shows that the ticket is valid.

So it returns back to the evidence being hidden and parallel construction being used to present the court case.