In your case I would not recommend to go to court. You tell the court there was no traffic behind. The cop will say yes there was. Whom do you think the court will believe? A defendant or the cop? Remember a cop is an officer of the court as well.
Written declaration will be the most effective way to deal with it, if you do not want to spend $400 on an attorney. You need to wait until the cop transfers the case to the court before you can do anything. QQH me your contact information. I will send you a copy of the declaration I wrote last year, for the same violation 22400(a), that I fought and won. Well, not really a victory since the cop did not reply and the case was dismissed.
