Well, just like what you mentioned on the USCIS rule, if it is not DUI or no actual arrest and finally a fine lower than 500 then you will be good, you can just write a note on the last page, to mention you have a pending criminal traffic ticket which is just a speed ticket
for some states, almost every traffic ticket (speed red light etc) is criminal, for example, Texas. In AZ, part of the traffic tickets are criminal. In CA, none of the serious traffic tickets (speed, stop sign etc) are criminal, all civil). So USCIS uses the DUI, fines, and actual arrest to determine if it is really a criminal and they need the document or not , otherwise almost every applicant who are in Texas have to mark they have criminals… almost everyone will receive a ticket in the life lol
the reason I know is that I received a criminal traffic speed ticket in AZ, I could not use driving school to dismissal it, but the Judge could determine in his or her favor that I could take driving school, or downgrade to civil level, or keep the criminal traffic. Lucky for me, as my first time, Judge gave me a chance to downgrade it to civil and driving school opportunity, so I could mark No for that I751 question as the final result was driving school to dismissal without any opportunity.
I hope my story can make you feel better, no worry about it, USCIS does not consider a criminal traffic ticket as a real criminal, and I was able to found a USCIS file which mentioned that a criminal speed ticket was still under normal traffic tickets (I did the research when I received that criminal ticket, however I could not find that USCIS file anymore lol)