I was in a similar situation. I had
* One speeding ticket for which I paid a fine
* One speeding ticket that I went to court in MA, contested and won. No fine paid
At the time of my interview I had documents for neither. The immigration officer stated that he did not care about the first one because there was a fine, I paid it and the matter ended there.
He and his supervisor insisted that the second one was important because _any time you make a court appearance_ they want to see a document from the court with the disposition. The IO also hinted that there was no need to have put a forgiven ticket on the application, but now that I've done it, and it is in their computer system, I do need to get the court document. It was easy enough but I lost 1/2 day vacation time and 30 dollars in parking, not to speak of the aggravation of driving twice in Boston traffic.
My suggestion is this:
* Do not take any chances, mention all speeding tickets
* For paid tickets, to be on the safe side, collect an official proof of payment with sign and seal. This most probably will be from your DMV.
* For forgiven tickets, go to the court and get a document with official sign and seal of it being forgiven
Important: Have all this ready and take it with you to the interview. That way you avoid having to run around after the fact. Also -- if your file is put in suspense waiting for your N-14 response, who knows when they will look at it next.