i thought of fighting a ticket once but i was told by a lawyer freind that traffic tickets are a bit different than other cases in many respects.
first the officer is not considered a wittness in most repects. the officer is a law inforcement agent they dont have to remember the color of your vehicle or directions or anything like that, the entirety of the evidence against you is the ticket which has the info of the offence. it can be agued but radar stuff has been standardized for decades and works very well (there is a legal term or it but i dont remeber it) if it has been calibrated and used properly (which the court assumes and is difficult to disprove) it is accepted as correct.
think of it this way if someone stole a computer from a store and there were several witnesses that is different than if an officer caught the thief in the act with cameras, a traffic violater is essentially cuaght in the act.
put it another way he has radar info (which he was trained to use) and you have a strong recollection of a speedometer (most of which are wrong by at least a few mph)