From City Council Staff:

Media stories are often misleading to the public regarding photo radar tickets. According to research done by our legislative analysts, a photo radar ticket is just like any other criminal or civil case in that the summons and complaint (what people refer to as a“ticket” in this case) must be served upon the individual. Service can be effectuated either through the mail with a return receipt or via personal service. If an individual is personally served then the law provides that the city can assess the actual costs for having the summons and complaint personally served via a process serving company. If we wanted, the city could make the decision to personally serve every photo radar ticket. It would result in a higher cost assessed against each violator as a result. Instead, we chose to mail the citations to the violators. If they voluntarily comply, the City does not personally serve the citation and the violator avoids the additional costs. If they don’t voluntarily comply, the City will attempt personal service of the citation. It is true that if the citation is not served at that point through either personal service or return receipt the case will be dismissed. If the City does effectuate service then the violator will be on the hook for both the penalty assessment as well as for the cost of personal service. The cost is $29.00 generally in Denver area—higher in outside jurisdictions depending on zone–with $10 added in if contractor has to go to another address due to move.