DURHAM - A 141-mile commuter rail system stretching from Goldsboro through the Triangle to Greensboro with a spur to Chapel Hill could be built in existing rail corridors for about $1 billion, according to a study released Thursday by the North Carolina Railroad Co.

The passenger trains would operate during morning and evening rush hours and could dovetail with another rail system in the Triangle that's under consideration, company officials said.

The state-owned private company owns a rail corridor running from Morehead City on the coast to Charlotte. It commissioned the 11-month-long study to determine the cost and feasibility of running commuter trains on its tracks along with existing freight and long-distance Amtrak passenger trains. Its consultant looked at a system with 29 stops in seven counties and 13 trains.

The next step, railroad officials said, would be for someone to undertake a ridership study to determine demand for the service.

Plans for passenger rail service in the Triangle suffered a setback in 2006, after Triangle Transit's 11-year effort to build a 28-mile system was halted. Federal officials said the Raleigh-to-Durham system wouldn't have enough riders to justify its $810 million cost.

But higher gas costs have led to more riders on mass transit systems across the country, including Triangle Transit's buses -- which set a ridership record this summer. With the Triangle's population expected to jump sharply by 2020, rail is becoming viable, railroad officials said.

"We think there's enough ridership and interest that one day soon it can be done, and the time is right around the corner," said Bill Kincheloe, chairman of the company's board of directors.

The study examined four potential commuter routes that would overlap in places: Burlington to western Greensboro, Greensboro/Burlington to Raleigh, Goldsboro to Durham via Raleigh and a spur line into Chapel Hill. Under the scenario in the study, there would be four trains in the morning and afternoon rush periods and one mid-day, round-trip train.

Funding for such systems usually comes from a mix of government sources, said Scott Saylor, the company's president. Half typically is paid by the federal government, and state and local governments split the remainder.

Triangle leaders already are pondering a proposal by a citizens' panel for more than $8 billion in mass transit investments by 2035. In May the Special Transit Advisory Commission recommended 56 miles of passenger rail and more buses and street car service.

Former Raleigh Mayor Smedes York, a vice chairman of the Special Transit Advisory Commission, said the two plans could complement each other because the railroad company's plan focuses mainly on an east-west corridor, while a north-south route from northern Wake into downtown Raleigh seemed to be the best choice for the first rail line in the system his group recommended.

"I think the two could be supplemental, and hopefully they would be making a link between Durham and Raleigh before we were ready to do that," he said.

But, added York, "I wouldn't worry about competing for money. It's going to be hard enough to get either of them started, and if we could just get something going with rail it would be terrific."

Most of the cost for the state railroad's plan would be for adding a parallel rail line and building bridges that would handle two sets of rails, Saylor said. Upgraded tracks, signals and stations would cost $658 million, according to the study. Trains and other equipment and facilities would cost another $356 million.

The N.C. Railroad Company's study can be found at www.ncrr.com.

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