[redyaris]

The first step is the preliminary hearing at which point the prosicuter will offer a reduced charge or fine. You refuse the offer and a trial date is set.
You then get disclosure on what evidence will be used against you at trial
you then prepare your defence.
Trial day arives and you show up at court and let the prosicuter know you are hear to defend yourself. You set down and wait your turn to be heard.
Your name is called, and you step up
The prosicuter then stands up and says the state would like to withdraw the charges.

The reason they don't drop charges before trial is they get lots of convictions on people who don't show up...

The reason they don't go to trial is that even if they get a conviction the judge is likely to say "fine 5 cents" or some other rediculess low amount. Sending the mesage... don't wast the courts time...