New Jersey, the state with the most highways per square mile, may sell the best-known of them all -- the 148-mile New Jersey Turnpike.

Acting Gov. Richard J. Codey (D) last month ordered a study on how to replenish the cash-strapped Transportation Trust Fund, the state's biggest source of highway construction and mass transit financing. One option is to sell the New Jersey Turnpike Authority, owner of the turnpike and the Garden State Parkway.

Sen. Jon S. Corzine (D-N.J.), the front-runner in the gubernatorial race that will be decided in November, has supported Codey's decision to consider selling or leasing the toll roads instead of increasing a fuel tax.

"People are looking seriously at selling the turnpike, because gasoline prices are making a large gasoline tax increase politically more difficult," said Damien Newton, New Jersey coordinator for the Tri-State Transportation Campaign, which advocates for regional transportation improvements.

Codey first proposed a toll road sale in January after reading that Chicago got $1.83 billion from investors who leased the right to run the city's 7.8-mile Skyway Bridge for 99 years, members of his administration said.

New Jersey faced a $4 billion budget deficit at the time, and selling the roads would have raised cash for balancing the budget. Lawmakers cut tax rebates instead. The state must now find at least $800 million in annual revenue by July 1 to pay for transportation projects.

A Spanish-Australian consortium called Skyway Concession Co. -- owned by Cintra Concesiones de Infraestructuras de Transporte S.A. and Macquarie Infrastructure Group -- leased the Chicago Skyway. The group will profit if the tolls collected exceed the amount spent to lease and maintain the road.

The turnpike and the 173-mile parkway produce $716 million in tolls each year, Merrill Lynch & Co. analyst Philip Villaluz said in a July report. Villaluz estimated the state may get $22.5 billion from selling the authority. The state Office of Legislative Services said the profit would be as little as $3.4 billion after the authority's debt is paid.

The turnpike runs from the Delaware Memorial Bridge in the southern portion of the state to the George Washington Bridge and New York. Singers from Simon and Garfunkel to Bruce Springsteen have invoked both the pace and the grimy urban landscape of the turnpike in their lyrics. Mob boss Tony Soprano takes the turnpike in the opening credits each week of "The Sopranos" cable television show.

The state could tap a large pool of potential bidders, mostly foreign. One of the biggest toll road operators is Cintra, a company controlled by the Spanish builder Grupo Ferrovial S.A. Cintra runs toll roads in Canada, Chile, Spain and Ireland. Texas has picked Cintra as a partner in a $36.7 billion plan to build toll roads in the state.

Any proposals on raising money to replenish New Jersey's Transportation Trust Fundwill likely be made after the Nov. 8 election, said Assemblyman John S. Wisniewski (D), chairman of the state Assembly's Transportation Committee. Corzine is running against Republican Douglas Forrester, and all 80 General Assembly seats are up for election.

Corzine said the gasoline tax should be raised only as a last resort. He wants the state to consider selling or leasing land along highways and rail lines, or toll roads.

Forrester called a turnpike sale "crazy," saying Democrats who control the Legislature would squander any profit. He said the state should dedicate more fuel taxes to the trust fund and take revenue from other programs.

"Selling a capital asset like this before we put our house in order is a dumb thing to do," Forrester said.

If the state does not replenish the trust fund, it will lose the ability to sell bonds backed by its revenue and the federal aid that matches what the state spends, Wisniewski said. The trust, created in 1984, was intended to be a steady revenue source for highway and mass-transit projects. Two-thirds of the money comes from fuel taxes and a third from sales taxes.

The fund's debt has surged to more than $7 billion as the state borrowed to pay for capital projects and to plug budget deficits. Starting on July 1, all of the revenue for the trust will have to be used for debt service.

Without new funding, the state will not have any money for new projects, said Thomas G. Dallessio, a vice president of the Regional Plan Association, which monitors transportation policies in New York and New Jersey. "We're going to have a transportation meltdown on July 1 if no one acts," he said.

New Jersey has the third-lowest gasoline tax in the nation, trailing only Wyoming and Alaska, says the American Petroleum Institute.

New Jersey would need a 20-cent increase in its gas tax to finance its transportation needs, Newton said. "Obviously, that's not going to happen," he said. "Everything has to be on the table, including looking at the toll roads."

Passing Woodbridge, N.J., the New Jersey Turnpike runs from the Delaware Memorial Bridge to the George Washington Bridge and New York. A sign in Newark points to the 148-mile New Jersey Turnpike. The state with the most highways per square mile is considering selling the expressway.