Virginia Attorney General Gerald L. Baliles brought his campaign for the Democratic nomination for governor to Northern Virginia yesterday, where he focused on the needs of the area's tangled transportation system.

Baliles addressed the issue at a Springfield news conference that initiated a daylong series of stops aimed at expanding his support in Northern Virginia, where Lt. Gov. Richard J. Davis is considered to be leading the more conservative Baliles for the nomination.

"Transportation is the big issue here, although it is not well understood," Baliles said. "The problems of Arlington and Alexandria are different from those in Fairfax County."

State officials need to understand, he said, that the transportation priorities of Arlington and Alexandria are tied to improving mass transit, such as the Metro subway system, which Baliles pledged to continue to support if elected governor.

Different solutions must be found for Fairfax and Prince William counties, where the growth in residential and employment centers within the counties is shifting attention from the need for commuter roads into Washington to improved cross-county road networks, he said.

Baliles endorsed legislation lifting the cap on the amount of bonded indebtedness a locality can incur for road improvements. A bill eliminating the current ceiling of $55 million over a five-year period is awaiting the signature of Gov. Charles S. Robb.

Baliles said he would be more receptive now than previously to allowing school board elections if the boards are given taxing authority. Virginia has barred school board elections since Arlington, the only locality ever to have an elected board, announced desegregation plans nearly three decades ago.

Unlike Davis, Baliles defended the so-called "Dillon rule," under which the powers of localities to enact laws are limited to those specifically granted to them by the General Assembly. Baliles said that, without the rule, some local governments could run roughshod over residents' rights.

Democrats will hold mass meetings around the state in late March or early April to select convention delegates, who will select their candidate for governor June 7 in Richmond.