A new audit found that Maryland’s State Highway Administration failed to issue tens of thousands of speed cameras citations. (Roberto Borea/AP)

The Maryland State Highway Administration’s failure to ensure the reliability of speed cameras in highway work zones cost the state $850,000 in potential revenue because tens of thousands of violations during the program’s first nine months did not result in tickets, according to a state audit.

The audit found that the highway administration did not run comprehensive tests to make sure the cameras were accurate and that it otherwise failed to make sure the cameras met performance requirements.

The audit report, issued this week by the state Office of Legislative Audits, examined the State Highway Administration from Aug. 1, 2008, through June 30, 2011. During that period, Maryland began its SafeZones program, which places automated speed cameras in work zones to discourage speeding.

Melinda Peters, head of the highway administration, said that the agency agreed with the report’s recommendations and that officials began making adjustments while the audit was being conducted.

Automated cameras that catch drivers speeding and running red lights have become common enforcement tools in some jurisdictions. Dozens of cameras, for example, are used in the District and have yielded tens of millions of dollars in fines.

A law enacted in 2009 allows speed cameras to be deployed in school zones and work areas around Maryland — and not just in Montgomery County, where a pilot program had been in place since 2006.

When Maryland tested SafeZones, from October 2009 through June 2010, cameras recorded more than 133,000 speeding violations. But only 56 percent of those violations resulted in citations because of “reliability and readability issues” with the cameras, according to the audit. Those problems resulted in the loss of $850,000 in potential revenue.

Peters said the administration was “very conservative” about issuing citations and wanted to be confident in the system before issuing tickets. She also said revenue is not the point of the cameras.

“The SafeZones program is not about revenue,” Peters said. “From the beginning, we’ve always said it’s about safety.”

The highway administration credits the cameras with recent declines in work-zone speed violations and the number of people killed or injured in related accidents. Since the program’s official launch in 2010, speeding violations in construction areas with automated cameras have declined by more than 80 percent, according to the administration.

Peters also cautioned against focusing too much on the pilot program, which was a test intended to help officials figure out what type of cameras to use. The cameras initially relied on radar, but authorities switched to laser-based technology because radar could not accurately monitor traffic across a multilane highway, she said.

In a letter to legislators on the Joint Audit Committee, acting legislative auditor Thomas J. Barnickel III said that the highway administration’s “tests to ensure the speed monitoring system’s accuracy were not as comprehensive as needed.”

Auditors said the automated cameras were not independently calibrated until nine months after the program formally began in July 2010, rather than at the start. The delay didn’t violate any law or contractual requirements, auditors said, but earlier tests could have ensured that equipment was working correctly when first used.

That is one of the adjustments the highway administration has already made, Peters said. Since early last year, cameras have been independently calibrated before being used.