While trucks offer a cost advantage on most short hauls and can reach places not accessible by rail, they consume about four times as much fuel to move a shipment as a train does, according to U.S. Energy Department data. Shipping rates are about five times higher for trucks than trains, said Amin of TCI, which is the fifth-largest shareholder of CSX, according to Bloomberg data.

The price of oil has jumped about 80 percent in the past three years. The Energy Department has predicted the commodity may rise as high as $100 a barrel by 2030.

"There's no question that trucking is less competitive now than it was three or four years ago," Amin said. "Unless oil prices are going to fall, and fall substantially, they're not going to be more competitive."

Outperforming trucks

Rail shares rose more than twice as fast as the Standard & Poor's 500 Index in the five years to May 31, while trucking stocks lagged behind the S&P 400 Midcap Index by 61 percent.

Congestion and labor costs are also hurting the competitiveness of trucks.

The American Association of State Highway and Transportation Officials cited highway congestion as a main reason why logistics costs rose to 9.5 percent of the U.S. gross domestic product in 2005, from 8.6 percent in 2003 — the biggest increase in 30 years, according to the Council of Logistics Management.

"The gap in service levels and traffic times is only moving in favor of the rails," said Satish Jindel, president of Pittsburgh-based SJ Consulting.

While truck drivers earn less on average than train operators, railroads use less labor per shipment than trucks, according to TCI.

Railroads are getting a double benefit from the rising price of oil, because it's also driving up domestic demand for coal and ethanol as energy sources. Both commodities are carried mainly by rail, as are corn and fertilizer, used to produce ethanol.

Union Pacific credited ethanol-related shipping for a 24 percent surge in first-quarter profit this year. The railroad's agricultural shipping revenue grew by 8 percent in the quarter as farmers planted the most corn since World War II, and chemical shipping revenue, including finished ethanol, rose 9 percent, Chief Executive Officer James Young said in April.

Surging imports from Asia are another booster for rail. The goods arrive on container ships to the U.S. West Coast and move inland by rail and truck. U.S. imports from China have more than quadrupled in the past decade.

Helping trains grab more West Coast port traffic is the increased number of rail lines that reach port terminals, said Paul Bingham, a Washington-based economist at Global Insight Inc. At the same time, congestion is increasing the time it takes for trucks to enter and exit ports.