After performing a thorough performance audit, Denver, Colorado's city auditor is no longer convinced of the value of red light cameras and speed cameras. The Denver Police Department (DPD) deputized the Dallas-based firm Affiliated Computer Services (ACS, a division of Xerox) to issue red light tickets at four intersections and speeding tickets throughout the city with five roaming vans. The program has little more to show for itself than a profitable bottom line.

"Unfortunately, DPD has not demonstrated that the photo radar program has a positive impact on public safety," City Auditor Dennis J. Gallagher wrote. "Because these programs were sold as public safety enhancements but are widely viewed as a cash grab, it undermines public trust to maintain photo enforcement programs that are profitable but whose safety impact has not been conclusively shown. If this situation persists, then the photo enforcement programs should be shut down."

The audit noted the speed van program has been operating since 2002 without any objective measurement of the impact on safety. Instead, city officials relied on the report of the number of violations generated by ACS as the sole measure of effectiveness.

"A reduction in violations does not necessarily entail a significant reduction in speed, nor does it indicate a decrease in accident rates or pedestrian injuries," the audit report noted. "Further, a 2006 internal DPD assessment suggests that DPD believes driver's habits adjust as citizens become familiar with the locations of the photo radar vans. Therefore, a decrease in violations does not directly correlate to a sustained decrease in speeds after photo radar is deployed to a different location."

Photo radar generated $3.6 million in revenue in 2010 and that amount is expected to top $7 million by the end of 2011 because ticketing operations expanded to seven days a week. With the red light camera program, certain types of accidents did decrease at the camera intersections, but the audit pointed out the city could not legitimately credit the improvement to cameras.

"At three of the four intersections with red light cameras, the number of right angle accidents was decreasing before the red light cameras were installed," the report explained.

The full safety impact is impossible to gauge because city leaders increased the duration of the yellow lights, enlarged signal heads and installed countdown timers at the intersections where cameras were installed. The engineering improvements helped make the intersection safer, but also reduced the number of violations issued. To boost the number of tickets, ACS and Denver began ticketing people who stopped at red lights -- but their car was photographed protruding a few inches beyond the stop bar. No other jurisdiction in the state tickets drivers who fully stop at red lights.

"Program revenues spiked largely due to more precise stop line enforcement," the audit explained, "By April 2011, ACS was able to dramatically increase the number of incidents captured by the red light cameras due to the upgrades."

These extra picky violations are the sole reason Denver's red light cameras are profitable.

"DPD should also be aware that while program revenues recently increased in Denver, if DPD or Denver policymakers change the violation point to better align with practices in other municipalities, program revenues may decline to the point where they do not meet the budget for the program," the audit explained.

In its response to the report, Denver police insisted it was impossible to conduct a study that would satisfy the auditor's concerns. The most the department would do would be to have ACS conduct a study to justify continuing the ACS program by June 30, 2013.

A copy of the audit report is available in a 4mb PDF file at the source link below.