In a lot of courts you are able to charge your plea on the same day as trial and guarantee traffic school. If the officer shows up and you want to do this, I think the judge would likely let you plead guilty
Yes, you can change your plea prior to trial and most judges provide you the opportunity to attend traffic school contingent upon your eligibility.
This is NOT legal advice. No attorney-client relationship exists.
You don't have to use all that motion language. Just say "Your honor, I do not want to proceed with trial, and I'd like to go to traffic school...." Also, the citation usually just has a due date on it, or an arraignment date- are you sure you are set for trial?
Better yet, keep fighting your ticket!
In most traffic courts, you will have the opportunity to change your plea and ask for traffic school. You don't need to state all of the above, you can simply tell the judge that you want to enter a plea of guilty, request a fine reduction, and ask for traffic school.