
Quoting
Mr. Knowitall
You were asked by whom to provide a copy of the ticket, for what purpose? The USCIS? How are they aware of the ticket? By virtue of your report to them?
It's possible that the only record of the ticket, if it was merely a warning, would be from the police department. You can investigate with the DMV of whatever state is involved to see if any other records are maintained. Perhaps you can convince whomever is requesting the record to accept a clean driving record abstract from the state, indicating no traffic offense convictions, if no record of the warning citation is available.