Delaware River bridge tolls for cars will rise to $4 on Sept. 14 from the current $3, and PATCO train fares will go up 10 percent at the same time, if the Delaware River Port Authority board approves hikes proposed yesterday.

Additional fare increases are set for 2010, with bridge tolls to go to $5 and PATCO fares to rise another 10 percent. Beginning in January 2013, increases tied to inflation would be imposed every two years.

As he announced the plan, chief executive John Matheussen said the port authority would end its decade-long practice of pumping hundreds of millions of dollars into economic-development projects on both sides of the Delaware.

He acknowledged that "we have heard the discontent" of commuters over using tolls for such projects as Lincoln Financial Field, the Kimmel Center, the National Constitution Center, and the Camden Riversharks' minor-league baseball stadium.

"Going forward, I want to assure you that new moneys raised from these proposed toll increases will not . . . be used for economic-development projects," Matheussen said. "Our efforts and the toll moneys will be dedicated to our assets, our bridges and PATCO."

Two public hearings on the increases will be held this month, and the board is to vote on the increases next month. Approval is expected.

Along with the toll increases, the agency would phase out its commuter discount. The $18 credit for 18 crossings a month on the same bridge would fall to $12 on Sept. 14. It would be reduced to $6 in September 2009 and end in September 2010.

The proposals come as higher gasoline prices are changing commuter habits. Traffic on the agency's Benjamin Franklin, Walt Whitman, Commodore Barry and Betsy Ross Bridges has dropped in recent months while PATCO ridership has risen about 7 percent.

The toll hikes are necessary to provide about $1 billion over five years to pay for bridge repairs and better railcars, port authority officials said yesterday.

"Simply stated, our bridges and PATCO need to be maintained and improved, and that requires an investment of money," Matheussen said.

The authority is already $1.2 billion in debt, partly as a result of the hundreds of millions of dollars spent for economic development.

Since 1999, it has spent $375 million to help build the Kvaerner (now Aker) Philadelphia Shipyard, Lincoln Financial Field, the Kimmel Center, the National Constitution Center, the Camden aquarium, and the Riversharks' stadium; to spruce up Admiral Wilson Boulevard in Camden; to invest in a still-unbuilt tram across the river; and to boost dozens of other projects.

In February, the bistate agency approved spending $10 million to help build a soccer stadium complex on the Chester waterfront.

"We hope it's not a done deal," Catherine L. Rossi, spokeswoman for AAA Mid-Atlantic, said of the fare and toll plan. "We hope the public input will be considered."

If the toll hikes go through, she said, "motorists need to see tangible benefits from those increases."

She was encouraged by the promise that the port authority would no longer fund economic development, "but we want some confidence in that statement," Rossi said.

The agency's debt burden, compared with its income, is significantly higher than that of other toll-collecting agencies in the region. About 42 percent of its revenue goes to pay annual interest and principal on its debt.

The Port Authority of New York and New Jersey spends 14 percent of its revenue on debt service; the Delaware River and Bay Authority, which operates the Delaware Memorial Bridge, spends 13 percent; and the Delaware River Joint Toll Bridge Commission, which operates seven toll bridges, spends 16 percent.

The Delaware River Port Authority expects to take in about $238 million this year, including $195 million, or 82 percent, from bridge tolls. Drivers make about 55 million round trips a year across the bridges.

Money from those tolls pays about half the cost of PATCO operations. The 37,000 daily riders contribute a little more than $20 million of the $40 million cost of the commuter rail line.

The last toll increase on the bridges was in 2000, when a round trip went to $3 from $2. The original round-trip cost on the Ben Franklin Bridge, which opened in 1926, was 50 cents. Through inflation, that would be about $6.12 today.

The last PATCO fare increase was in 2001, when the maximum round-trip fare went to $4.90 from $4.20. The maximum when the 14-mile line opened in 1969 was $1.20, equivalent to $7.08 today.

Contact staff writer Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.