TRENTON - Gov. Corzine's toll-hike plan could raise billons more than is needed to operate New Jersey's highways and pay off a $38 billion bond issue, according to an Inquirer analysis and new information provided by the Corzine administration.

Corzine aides disclosed late last week that by 2022, the last year for a proposed run of toll increases every four years, fares at their permitted maximum would generate $4.2 billion in annual revenue.

Yet only $2 billion would be needed each year to pay off Corzine's proposed $38 billion in borrowing to slash state debt and improve transportation, the aides acknowledged. An additional $600 million would go annually to pay the operating costs of the highways, the aides said.

That leaves $1.6 billion.

Corzine says any extra annual toll revenue could be used to reduce the toll increase or spend more billions on transportation. He said his proposed nonprofit oversight corporation, not elected officials, would decide.

A big plus of his plan, Corzine said, is that any windfall wouldn't go to private investors. This has happened elsewhere when governments "monetized" highways.

"If it does produce 'profit,' " the Democratic governor said, putting quotation marks around the word, "the benefit will be for the citizens of New Jersey."

Republicans in the Legislature, who are in the minority there, have lashed out at Corzine's plan. One Republican critic, Assemblyman Richard A. Merkt of Morris County, said he was troubled that the yearly amount from tolls might eventually exceed the annual debt service.

"The idea of raising more money than you actually need just tells me that this entire enterprise has not been thought out correctly," Merkt said.

Corzine's transportation commissioner, Kris Kolluri, said the extra revenue after 2022 could be used to improve New Jersey's roads, rail lines and bridges for decades to come.

Kolluri said the excess toll money could be "a down payment to make sure the next generation has a stable, dependable transportation system."

In a meeting Thursday with The Inquirer's editorial board, Corzine said he was not worried about the loss of direct political control over turnpike tolls for 75 years, the length of the bond.

"They won't be living in isolation," he said, referring to the board members of the new nonprofit body. "They will be very visible and transparent."

Corzine does propose one key control: The nonprofit could use excess revenue only to lessen the toll-hike schedule or improve transportation.

Financial experts say Corzine's borrowing of up to $38 billion would be the biggest bond issue ever pushed through by a governor.

The lenders would be paid back by increased tolls on the New Jersey Turnpike, the Garden State Parkway, and the Atlantic City Expressway.

Tolls could go up by a maximum of 50 percent in 2010, 2014, 2018 and 2022, plus by smaller amounts pegged to inflation.

Corzine would use up to $12 billion of the bond sale to cut the state government's massive debt, which has accumulated to cover pensions and build schools, among other expenses.

An additional $15 billion would pay off the debts of the New Jersey Turnpike Authority and the Transportation Trust Fund, which pays for improving roads, mass transit, tunnels and bridges across the state.

Paying off the Transportation Trust Fund, Corzine noted, would free up the 101/2-cent gas tax for spending on new highway projects.

And an additional $5.5 billion would go to other highway projects, including widening the turnpike.

After all this transportation-related spending, Corzine said, some of the excess revenue from the toll hikes may go to even more highway, bridge and mass-transit projects.

"You have other things you have to do here," he said. "You're going to have new capital plans for the turnpike."

If the board chose to use the extra money to limit the toll hike, it could reduce the maximum fare in 2022 for an average trip of 23 miles by about 40 percent, from $9.85 to about $6.

The Corzine administration declined Friday to release its year-by-year forecast of revenue and spending under his plan. Lilo Stainton, the governor's press secretary, said the figures would be made public this week.

The administration's estimate of $4.2 billion in new toll revenue in 2022 appears to be conservative, assuming a reduction in traffic and low inflation.

If the number of drivers doesn't change, the maximum toll hikes would generate yearly revenue of about $6 billion, according to an Inquirer analysis.

Corzine has said it was crucial that the nonprofit body be separate from the elected state government. That way, he said, investors would have confidence they would get their money back once they lent it to New Jersey - and could rest easy that no politicians would reduce tolls and threaten their payback.

Moreover, Corzine said, such independence was legally needed to make sure the $38 billion bond issue was not an official debt of the state.

However, a group that has organized to block Corzine's plan said the proposal would rashly give power to a "non-accountable body" for generations to come.

"Taxes shouldn't be decided by unelected bodies. There's a fundamental premise: No taxation without representation. I think we had a little fight about that once," said Peter Humphreys, spokesman for the opponent group, Save Our Assets NJ.

The group's lobbyists and Web site are bankrolled by the American Trucking Association and unions for turnpike workers. Humphreys is a volunteer.

Merkt, the Republican lawmaker, said he, too, was worried about a loss of public participation.

"It is part of what I think is a dangerous trend in New Jersey government," he said. "More and more authority is being invested in bureaucrats and less and less in elected representatives."

Other analysts found those criticisms unconvincing.

Richard Leone, former New Jersey treasurer and former chairman of the Port Authority of New York and New Jersey, said the proposal would properly minimize political interference with the toll roads.

"It prevents future governors and legislators from saying, 'We need the money this year for other things,' " he said.

As for the prospect of excess revenues, Leone said, "I've heard people argue both sides of whether there will be extra money."

Jon Shure, Democratic Gov. Jim Florio's press secretary and now president of New Jersey Policy Perspective, a Trenton research firm, said much would hinge on the merits of those who would operate the new nonprofit.

Under the plan, Corzine would essentially select the first round of members. After him, the board would be self-replicating for decades, its own members choosing their successors.

"A lot will depend less on the structure than on the credibility of the people who run it," Shure said. "To a certain extent, the governor is saying, 'You'll see.' "