A developer and part-owner of the Dulles Greenway said yesterday that he plans to offer Virginia $5.7 billion to take over the Dulles Toll Road and build four express toll lanes on it, one of several such proposals expected today when the deadline for private offers expires.

Franklin L. Haney, who also is bidding to buy the Washington Nationals, said yesterday that his proposal would include as much as $717 million to fund the state's share of building a Metrorail line to Dulles Airport, plus "several hundreds of millions of dollars" more to make improvements to the toll road and surrounding highways.

Virginia would get $700 million in cash on the day the deal was signed -- the amount needed to cover the first phase of the rail project, highway fixes and some state debt.

Haney's group, Dulles Express, would operate and maintain the toll road and express lanes for 50 years in exchange for the revenue it generates. The group also would operate and maintain the Dulles Access Road, a free highway that provides a direct link to the airport. Haney pledged not to raise fees on the toll road, except for an already planned rise in 2010.

"We can solve that corridor's problems without costing the state or county any money," said Haney, who is partnering with several transportation firms and Merrill Lynch. "We know we have the best deal."

The process began in July when the state received an unsolicited offer from a group that includes former Democratic governor Gerald L. Baliles, Clark Construction Group and Shirley Contracting under the state's Public-Private Transportation Act, which allows private groups to propose highway fixes. The act stipulates that once an offer is received, other firms have 90 days to submit their own. That deadline is today.

The next step is for state officials to form an advisory panel of public and private transportation experts to sift through the proposals and make a recommendation about which ones, if any, the state should pursue. If a proposal clears that hurdle, state officials negotiate directly with the winning group. The length of that process varies, but likely would take at least a year in this case.

In recent years, Virginia has signed a handful of deals in which private groups agreed to build or widen roads in exchange for toll revenue, but a deal on the Dulles Toll Road would take the state a step further because it would be selling the rights to an existing asset. Dulles Toll Road had a profit of $14 million in fiscal 2005.

If Virginia opts for any one of the proposals, that plan would be the latest in a small but growing number of such deals in the nation. The most recent of those was a decision by the city of Chicago to lease its Skyway toll road for 99 years to a private firm for $1.8 billion. The company that inked the Skyway deal, Macquarie Infrastructure Group, joined the Baliles group this fall.

The Dulles Toll Road is an eight-lane highway that stretches 14 miles between the Capital Beltway and the privately owned Greenway. It carries about 200,000 vehicles daily and runs through Reston, Herndon and Tysons Corner. Tolls on the road range from 50 to 75 cents, and state officials said they would maintain control over the rates as part of any deal.

The original offer on the toll road proposed a 50-year deal to take over the road, make 19 improvements to it and fund the rail project in exchange for toll revenue

Curtis M. Coward, a principal of the group that includes Baliles, said "We expect competition and we're prepared to compete."

Another private group said yesterday it would submit an $800 million offer to build 122 miles of express toll lanes on the toll road, Interstate 66 and Route 28.

Ken Reid, spokesman for Virginia Mobility Associates LLC, said the plan would add an express toll lane in each direction on I-66 inside the Capital Beltway and on Route 28. The group would add four express lanes on the toll road and on I-66 between the Beltway and Route 28 by building a new lane and converting a carpool lane in each direction. The group would add four lanes on the access highway between I-66 and the toll road.

The plan, dubbed the "Dulles-to-DC-Loop," does not include money for Metrorail or other projects. "This is a straight highway proposal," Reid said. "It is a proposal that will alleviate congestion, and Dulles rail does not alleviate congestion."

The express toll lanes that are at the heart of both deals are quickly gaining in popularity across the Washington region and the nation. Virginia and Maryland officials announced plans Wednesday to study adding them to 28 miles of the Beltway and part of I-270. Another plan to add them to 14 miles of the Beltway in Virginia is underway, and the state is soliciting offers to build them on I-95 and I-395 between Spotsylvania County and the 14th Street Bridge.

Express toll lanes are designed to virtually guarantee drivers a congestion-free ride because tolls would vary with traffic, rising during peak times to control demand.

State leaders were wowed by the $5.7 billion figure attached to Haney's offer and said it was more in line with what they had in mind for the toll road.

"Just basing it on what they got for the Chicago Skyway, I thought the first bid was probably a little low," said House Speaker William J. Howell (R-Stafford), who has pushed for such deals. "I think this is tremendous."

Howell and other Virginia government officials said they were expecting two to three additional offers today.

Tamara Neale, spokeswoman for the Virginia Department of Transportation, said, "We expect to receive competing proposals. We look forward to reviewing them."