Revenue-hungry Fairfax County is thinking about expanding the use of volunteers to write parking tickets after a five-year decline in the number of citations issued and amount of revenue collected.

The Board of Supervisorsauditor of the board made the recommendation in a draft report that found citations had declined about 16 percent over a five-year period. Revenue fell about 5 percent despite a boost in the amount of parking fines and expanding the number of parking ordinances, the audit says.

To beef up collections, county auditors recommended that Fairfax follow other jurisdictions that have created special units of volunteers to enforce parking violations. Supervisor John W. Foust (D-Dranesville), who heads the audit committee, said he would forward the recommendations to the full board.

The auditors, who presented their findings at a board of supervisors committee meeting Tuesday, found that the total number of citations issued by the county had fallen from 73,523 in 2006 to 61,719 in 2011. Revenue dropped $175,389 from $3,304,380 to $3,128,991 in the same period.

The decline was attributed to vacancies in the police department’s traffic division and the distraction of other duties, such as child seat safety checks or setting up speed-check trailers. Collections also tapered off after the county ceased to require residents to display a personal property tax decal on the windshields of their vehicles in 2006. Prior to 2007, failure to display the decal — which was proof of tax compliance — was one of the county’s top five violations, the report says.

The audit department said county police have a separate parking enforcement unit that includes 10 at-large parking enforcement officers and eight who are assigned to each police district. Police officers, police volunteers, sheriffs deputies, fire marshals and Metro transit police also are authorized to write parking tickets, the report says. But that’s not enough, and the need will rise further with the opening of Metrorail’s Silver Line extension, the report says.

Most violations cost about $50, the report says, though some, such as parking in a space reserved for people with disabilities, can run as much as $500. The fines were last increased in 2010.The county’s fines also match or exceed those imposed by the city of Alexandria and Arlington and Loudoun counties, the report says.

To increase revenue, the report recommended expanding the use of volunteers to enforce parking rules, especially for handicapped parking, as has been done in Virginia Beach and Phoenix, Ariz.

The report also recommends better tracking and monitoring of enforcement officers’ time, and collaborating with the Transportation Department to develop a strategy to handle the increased workload expected to come with the opening of the Silver Line.

Even with a team of volunteers dedicated to parking enforcement, Fairfax County would still have a long way to go to catch up with the nation’s capital. AAA Mid-Atlantic, using the Freedom of Information Act, reported in March that the District issued 1.6 million tickets and collected $92.6 million in fines in 2011, up from 1.54 million tickets and $80.4 million in the previous year.