Speed camera calibration info

Every speed camera - fixed or mobile - is supposed to be tested and calibrated periodically. This information is vital for drivers charged with speeding. This information must be provided to anyone upon request; but since the data is not personal, why must one pay for it, wait for it and go through the procedures? Just to make it hard and deter drivers from contesting potentially unlawful fines? This is not right, this data should be available publicly constantly accurately and free.