Ken, Speed limits are referred to in the law as "Strict Liability" regs, and here in Calif they ahve teeth. This means that if you violate them, you have no defenses! 26mph in a 25 zone is a violation. Signatures on tickets have no effect upon liability. It usually only advises the court that you were aware you were cited. You might be cooked. Ask for a hearing and hope the P.O. does not show up. He has to be there or your 6th amendmenment right is violated. If the P.O. shows up, get out your checkbook!