Virginia's independent gubernatorial candidate, H. Russell Potts Jr., plans to call for an additional $2 billion in annual state spending to improve the road and rail network when he unveils his transportation plan tomorrow.

Potts will suggest that the state can begin immediate and aggressive investment in the transportation system by raising some taxes -- including those on sales, income and cigarettes -- while adding tolls to some interstates and encouraging public-private partnerships, according to a copy of the plan provided by the candidate's campaign.

Although politicians consider Potts a long shot for the governorship, his emphasis on finding new ways to finance popular transportation projects resonates with many of the state's business and civic leaders who lack enthusiasm for the proposals offered by the major-party candidates.

In a new Washington Post poll, 89 percent of registered voters said that transportation was an important issue in deciding how to vote in the Nov. 8 governor's race.

Potts's plan would pump billions of dollars into initiatives including extending Metrorail to Dulles, widening Interstate 66 inside the Capital Beltway and building a third crossing of the Chesapeake Bay in Hampton Roads. It stops short of endorsing specific forms of tax and fee increases and does not call for an immediate increase in the state's 171/2-cent gas tax. For fiscal 2006, the transportation budget is $4.1 billion, a quarter of which is federal funds.

Potts's proposal to raise an unprecedented amount of money through a potential combination of levy and fee increases is a sharp break from the transportation plans offered by Potts's opponents, Jerry W. Kilgore (R), the former attorney general, and Lt. Gov. Timothy M. Kaine (D).

Kilgore and Kaine have outlined their own solutions for fixing the transportation network, but both have eschewed directly raising taxes or setting detailed road maps as to how they would unclog roads or provide relief to an increasingly crowded public transit system.

Kilgore said he would create regional authorities that could operate toll roads and borrow money using low-interest bonds. He would allow the regions to hold referendums on whether to raise taxes to fund transportation programs.

Kaine has said he will not consider any tax increases for transportation until he feels comfortable that money raised for such projects is "locked up" in the state's transportation trust fund through a state constitutional amendment or other means. His transportation proposals focus on improving coordination between state and local governments as they plan new roads.

"We stand in stark contrast to them by accepting the reality and responsibility that there is a problem that needs fixing," said Tom D'Amore, Potts's campaign manager.

This is a crucial time for Potts, a Republican state senator from Winchester. The Post poll found that about half of respondents had no opinion of the fiery politician. Only 5 percent of registered voters said they would vote for him.

Students of Virginia politics said that Potts needs to do something to call attention to his campaign. Furthermore, Potts will need to hit 15 percent in two statewide polls by early next month if he is to participate in a gubernatorial debate that will be televised statewide.

"What he's trying to show is that he's someone who will stand up and tell people what it's going to take, that he's the one person in the race who is not nibbling around the edges on this problem," said Robert D. Holsworth, a political science professor at Virginia Commonwealth University. "He's putting down a marker on a major issue to provide a contrast."

Advocates of transportation improvements described Potts's call for an annual $2 billion in spending as both admirable and unrealistic. Each component of the plan would run up against lawmakers dead set against such increases, particularly after the fight over last year's tax package.

"It would be shot at from all directions," said Steve Haner, the lobbyist for the Virginia Chamber of Commerce and a spokesman for the advocacy group Virginians for Better Transportation.

But he added that Potts's approach grasped the need to calibrate revenue-raising with the actual cost of Virginia's transportation projects.

"He's being realistic in that he is trying to match the amount of money we would need to raise to actually make a difference," Haner said.

Gubernatorial candidate H. Russell Potts Jr. has not specified tax increases.