https://www.uscis.gov/sites/default/files/files/nativedocuments/July2008Q%26A.pdf
10.
Question: What documentation is USCIS looking for on N-400 applications for clients who have traffic citations only (no arrests), such as speeding tickets? This is in reference to the Good Moral Character section, question 16, which asks if you have ever been a rrested, cited, etc. Also, what is expected at the N-400 interview regarding these traffic tickets?
Response: Typically if an individual only has minor traffic citations with no arrests resulting (i.e. speeding tickets), they will not be required to submit any additional information with the N-400. However, if, during the course of the interview, an adjudications officer determines that there are
circumstances that warrant further investigation, (e.g. there is an indication that the applicant has failed to pay fines associated with the citations), the officer may request additional documentation. (e.g. payment, certified police/court documents indicating such).