If yhe radar /lidar box on the citation is empty, chances are he paced you. In that case, speed trap laws do not apply. However, the basic speed law defense, that your speed was reasonable and prudent for conditions, applies for sure if you drove 55mph or less. I would suggest writing your tbd based on that. Do mention the exact speed you travelled, if known and less than 55mph. Obvioisly, the slower, the better. Do mention it was a divided higway, because that makes 50-55mph more reasonable. If found guilty, call the court and request the officer's tbd statement. That will tell you if he used radar or not, and help you plan TDN strategy. You can ask for traffic school if you lose TDN. I wouldn't plead no contest. If you nonethwless don't want to do TDN, go to walk-in court and ask to be re-arraigned. That way you'll be able to talk to a judge and ask for traffic school.