How hard is it to mitigate a school zone speeding ticket?

Mitigation factor are specific to your individual case and are factors that tend to soften sentencing. They are not defenses, but reasons to explain why something happened. Unless you had a real emergency, I don't see any mitigating factors that you could say that will actually have any effect. People say they were running late for work, school, etc., but how is running late a good reason to speed in a school zone and risk injury to a child? So unless there was some type of real emergency, I don't suggest trying to minimize your speeding because it won't work and could annoy the prosecutor.

"It is not a ticket per se". Parking tickets are tickets. Camera tickets are tickets. Around the Seattle area, most courts normally do reduce the fines for most types of tickets for persons who show up to mitigate. On another hand, many courts likely will not reduce fines for speeding in a school zone. How much is your time worth? If you go to court, you likely will spend about four hours that day on the ticket. You have to drive to the court house; you have to sit in the court room waiting for your turn; you have to drive back to wherever you are going. Since the camera ticket should not affect your insurance premiums or have other effects besides the fines, you will have to make a decision based on the potential savings from the mitigation versus the costs of doing the mitigation.

It is not hard at all, depending on the court they normally reduce these tickets when you agree to mitigate. Again depending on the court, they may allow you to do your mitigation by mail.