As a general rule no statute of limitations is in place on speeding citations. A warrant may be issued if you failed to appear or if you declined to pay off the ticket. The judge often enters it as a plea of guilty because you didn't show. Then, the court can collect the fine many years later. In Illinois, because of the rough economy, I see local traffic courts trying to collect fines from 25 years ago.
Get an attorney to help you clear up any outstanding warrants.