I don't know if that's accurate either. In any case, his reading corresponded the speed I was going (within the margin of error for a speedometer, which can be

I don't know if that's accurate either. In any case, his reading corresponded the speed I was going (within the margin of error for a speedometer, which can be large), and it was calibrated, so I signed the citation and paid the fine. Again, if cops are actually going around setting values to get citations, there are larger systemic problems. Also, many vehicles have GPS and other datalogging showing actual speeds, so if the cop is faking the numbers, that's going to start showing up in court.