Virginia's county and city governments should be allowed to levy new sales or income taxes to help finance the mounting costs of Metro service in Northern Virginia and local bus systems in other parts of the state, according to a new report.

The study, prepared for the Virginia Department of Highways and Transportation by Richard Grefe Associates, a Washington-based consulting firm, recommended that counties and cities be authorized to impose either a 1 percent sales tax or a surcharge on the state income tax of up to 10 percent.

The special levies would be designed to offset rising multimillion-dollar deficits incurred by the Metro bus and rail system and 18 other bus systems in Virginia. This gap--between the transit systems' revenues from fares and other sources and their operating expenses--is expected to widen by more than $50 million during the next six years, the study warned.

The $38,500 study, made public in draft form during a meeting this week in Alexandria of the Virginia Association of Public Transit Officials, is expected to fuel renewed debate over longstanding proposals for special taxes to subsidize transit costs.

Especially noteworthy, some officials said, is the consultants' finding that the transit deficits--long a cause of concern in Northern Virginia--are climbing elsewhere in the state. As a result, these officials suggested, political pressure to establish new transit subsidies may spread throughout Virginia, improving prospects for new legislation.

Virginia's counties and cities are not permitted to impose special sales or income taxes unless they are authorized by the General Assembly. Metro service in Northern Virginia is currently subsidized, in part, by a state-authorized gasoline tax. State appropriations for public transportation also have increased in recent years.

Nevertheless, the consultants concluded, many Virginia counties and cities may be forced to reduce transit service in coming years unless new taxes are authorized. "In the last few years the extent and frequency of transit service has been pared so substantially that the best description of current service levels is 'anorexic,' " the report said.