Fortunately, there are some circumstances where you can dispute a speeding charge, but don't assume we'll be advising on any 'loopholes'. According to Motoring Solicitors, these are some of the valid circumstances where you can dispute the ticket. You should take legal advice, however, as challenging the calibration of a speed camera could have significant cost implications for your case. Inadequate Speed Limit SignsYou may be able to challenge the fact that speeding signs are inadequate, obscured, or not visible. Recommended reading:'Ultra speed camera' can see inside driver's vehiclesIf a speed camera is not visible can I challenge the fine?