Mitigation hearing or contest hearing?

I traveld to seattle in the spring break. I was driving in carpool zone downhill in Washington state(I-5), the vehicle in front driving too slow, I speed up for a moment to change line, the traffic next to me is fast so I had to hit the gas pedal (no vehicle in front in the line nest to me), I got a ticket of 70mph, the limit is 60. I'm 18 years old and just got the license for couple months, the record is clean, should I choose mitigation hearing or contest hearing?