Prince William County officials presented a proposed $878.3 million general fund budget Tuesday that would raise taxes slightly to help reinvigorate the county's road and library projects.

The proposed budget is 4 percent higher than the fiscal 2011 budget. The tax hike would fund road projects from the 2006 bond referendum and two new libraries, including one that has been planned for 20 years, county officials said.

"We believe right now is the time to reinvest in our future," Prince William County Executive Melissa Peacor said. "There is no better time to start these capital projects."

The proposed tax rate is $1.213 per $100 of assessed value. Although the rate would be lower than last year's rate, the average residential tax bill would go up 3 percent to about $3,200, because property assessments are expected to rise. The average commercial bill would decrease almost 10 percent, county officials said, noting that taxpayers would also pay a 7.4-cent fire levy, or about $197. The residential bill, however, would still be lower than it was in 2007 and 2009.

Peacor said the average tax bill in Prince William would also remain lower than bills in neighboring jurisdictions. Loudoun County's average residential tax bill is expected to be about $5,200. Alexandria's bill is expected to be about $4,400.

Road projects that would start under the proposed transportation package include expanding portions of Prince William Parkway, Minnieville Road and Route 1 and extending Rollins Ford Road, officials said. More than a dozen projects are in the funding package.

The proposed libraries in Montclair and Gainesville would open by September 2015. County officials said the fire levy would fund the construction of the proposed Bacon Race fire station scheduled to open in fiscal 2016 on Prince William Parkway and Davis Ford Road.

The proposed budget would include no layoffs for the first time in four years, a 2 percent merit-based salary increase for employees, a $421.7 million transfer to the schools and no cuts to agency base budgets unless they come from the state.

The police department is scheduled to lose six vacant positions because of state cuts, Peacor said, noting it is not the board's policy to replace state or federal funding cuts. Since fiscal 2008, the state has cut almost $3 million from the county's police department. Under the proposed budget, the county would not add police positions until fiscal 2013.

Peacor said county officials have about $8 million in savings, mostly through base budget reductions. With that savings, Peacor proposed budgeting an additional $391,900 to the Department of Social Services, which has received 82,000 new applications for assistance in the past four years. Peacor said the money would fund 13 full-time positions, five of which would expire in 36 months.

"I think that is complete overkill," Prince William Board of County Supervisors Chairman Corey A. Stewart (R-At Large) said about the proposed social services positions. "I know there are justifications, but if it were up to me, I would move that money over to hire more police officers. The recession will end," and fewer people will need assistance.

The ambulance fee program will bring in about $3.6 million to the fire and rescue department. The money will go toward staffing a 24-hour advanced life-support unit and a new daytime career transport unit.

Peacor said there supervisors will discuss and allocate the remaining $500,000 in the budget.

Supervisors will speak with department heads over the next two months. Residents will have their say on April 4 and 6. The board will vote on the final budget on April 26.