According to the Houston Police Department only 25% of the issued citations have been paid since the program began in September of 2006. Violators have 45 days to pay or request a hearing to contest the citation. Unpaid citations are referred to collection agencies, so nonpayment could show up on credit reports. But because camera-generated citations are civil, not criminal, courts can't issue arrest warrants for those who don't pay, as they can for drivers who don't pay speeding tickets — or red-light tickets issued by police who witness violations. Some states threaten to suspend drivers licenses but haven't heard of any cases as such. Very few people know anything about law and there are still many inconsistencies from city to city across the U.S.