“This has caught everyone off guard,” said Roger Downs, a conservation director at the Sierra Club in Albany.

About 75 percent of Bakken oil production travels by rail and as much as 400,000 barrels a day heads to the East Coast, said Trisha Curtis, an analyst at the Energy Policy Research Foundation. Albany gets 20 to 25 percent of the Bakken’s rail exports, according to various analyst estimates.

“Albany has become a big hub,” Ms. Curtis said.

But opposition is starting to form over new plans by one energy company to expand operations here and, possibly, ship crude extracted from the oil sands of Canada into Albany. The company, Global Partners, which pioneered the use of Albany as a crude-oil hub, is also looking at shipping oil from a terminal in New Windsor, just north of West Point.

The rapid growth in the oil-by-rail business is raising alarms. Railroads carried more than 400,000 carloads of crude oil last year, up from 9,500 in 2008, according to the Association of American Railroads. Federal regulators have been under pressure to address the industry’s safety and recently outlined a series of voluntary steps, including slowing oil trains in some major urban areas.

These steps are not enough to protect many communities along the rail lines, Senator Charles E. Schumer, Democrat of New York, said this week. This includes many places in upstate New York, like Buffalo, Rochester, Utica, Syracuse and Albany, that have seen higher rail traffic. He compared the industry’s use of outdated tank cars to “a ticking time bomb” and urged federal regulators to quickly retire these older cars, known as DOT-111s, in favor of models built after 2011 that have better protections.