WASHINGTON — A push by Sen. Johnny Isakson, R-Ga., to overhaul the country’s passenger rail system could boost efforts for a long sought-after, high-speed Chattanooga-to-Atlanta line.

Sen. Isakson said he intends to co-sponsor a bill that Sen. John Kerry, D-Mass., will introduce, that would change the way rail transportation is funded. Sen. Isakson’s interest in the bill stems from his support for a high-speed rail corridor from Birmingham, Ala., to Washington, D.C. Spurs from Atlanta to Chattanooga and Savannah could be part of the mix.

“Rail has to change,” Sen. Isakson said. “It’s totally subsidized differently than any other form of transportation. Ports, highways and airports all have user fees but not rail.”

If government puts in the infrastructure and lets the private sector run the lines, he said, “it can be profitable.”

Sen. Kerry’s office did not return calls seeking comment on his bill. However, his bill reportedly would authorize billions of dollars in bonds to upgrade the country’s rail infrastructure and facilities. Under the bill, user fees on private rail operators would pay for the improvements, similar to those paid by the airline industry.

Sen. Isakson said the new funding mechanism could give rise to a network of high-speed rail corridors, similar to one that already exists from Washington to Boston, one of Amtrak’s few profitable lines.

He said an ongoing $4 million federal feasibility study estimates a similar rail line between Atlanta and Washington could take 15 percent of the traffic off Interstate 85. And with high gas prices, a strong passenger rail network could help reduce the country’s oil consumption, he said.

An $8 million feasibility study on a high-speed rail route between Atlanta and Chattanooga also is ongoing.

Chattanooga Mayor Ron Littlefield, who touted the high-speed rail during his mayoral campaign in 2005, said Sen. Isakson is “definitely onto something.” Although rail has been criticized by skeptics as being too expensive, it compares favorably to building interstate highways and airport runways, he said.

He noted that Atlanta’s Hartsfield International Airport recently finished a $4 billion runway, which is about the same cost projected for an Atlanta-to-Chattanooga high-speed rail line.

“We’re bumping up against the limitations of highway travel, and we’re seeing the woes of the airline industry,” Mr. Littlefield said. “Passenger rail is the logical way to go.”

The only difference he has with Sen. Isakson’s plan, he said, is that he would concentrate efforts on a line from Atlanta through Chattanooga, then to Nashville and on to Chicago.

“There are arguments that could be made on where the corridor should go, but out of necessity, the country is going to be building a passenger rail system, and soon, because of where we are with energy,” Mr. Littlefield said. “We can produce electricity with nuclear plants, and that takes us off our dependency from oil.”

Sen. Bob Corker, R-Tenn., said he has had a few discussions with Sen. Isakson about the bill and agrees that passenger rail should have a major role in the country’s transportation future.

“From a national security standpoint, I think it’s important to be able to move large masses of people by other modes than air,” Sen. Corker said. “We’re doing everything we can to make sure the Atlanta-Chattanooga vision stays alive.”

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