Mitigation is a fancy word for asking the judge to lower the fines (or order an alternative sentence such as traffic safety school). In order to mitigate your traffic ticket you have to first admit that you committed the infraction. The purpose of this hearing is to explain why you committed the violation and ask the judge for a little monetary mercy. This is not the forum to argue why you think you are not guilty. Pros: The judge will usually grant your request to lower the fines, Cons: Most offenses will be reported Washington DOL and your insurance company. Thus, while you may save few bucks initially, you often pay more in the long run in the form of raised insurance rates and missed job opportunities. Many courts allow you to ask for mitigation by submitting a written statement through the mail if this is the path you choose.
This is your chance to fight the ticket on procedures and facts. You will present evidence and make legal arguments in front of a judge. The burden is on the prosecution to prove by a preponderance of the evidence that you committed the charged offense. In my experience most contested hearings are won on technical defenses, not the facts. A ticket lawyer can usually better spot and argue the winning issues, than can the layman. Pros: You may be able to get the ticket dismissed or reduced to a non-reportable violation. Cons: Sometimes this is an all or nothing proposition Law enforcement is getting much more proficient and aggressive at the traffic ticket enforcement process. If you lose you pay the ticket and it goes on your record. NOTE: In Washington, you must request a contested hearing within 15 days of receiving the notice of violation or you lose the right to fight your Everett speeding ticket.
A ticket "deferral" means final judgment is postponed for a period of time (up to 1 year in Washington). If the driver has no new violations during this period the ticket is dismissed. You will not pay a fine, but the court will charge administrative fees. Washington law allows you to defer one moving violation (e.g. speeding ticket) and one non-moving violation (e.g. no seatbelt) every seven years. Some offenses are excluded, such as school zone violations. If you qualify the judge then has the discretion to grant or deny your request for a deferral. Local court rules often further dictate what the judge can do. Pros: This is a great if you are CERTAIN you won't get another ticket during the deferral period (and almost certain you won't be cited for another seven years). Cons: You usually have to appear in court to ask for a deferred finding. If you get another ticket during the deferral period you will be found to have committed the original ticket without further hearings.