BILLINGS, Mont. — Railroads that haul volatile crude oil shipments have reached an agreement with US transportation officials to adopt wide-ranging, voluntary safety measures after a string of explosive and deadly accidents.
The agreement between the US Transportation Department and the Association of American Railroads was obtained Friday by the Associated Press.
It calls for railroads to slow down oil trains from 50 to 40 miles per hour through major cities, inspect tracks more frequently, and bolster emergency response planning along routes that carry trains hauling up to 3 million gallons of crude each.
The new safety steps would begin going into effect in late March and be fully in place by July 1.
After a boom in domestic drilling in recent years, oil trains now travel thousands of miles from oil producing areas, including the Northern Plains, to coastal refineries and shipping terminals along the Mississippi River and other major waterways.
The agreement does not resolve concerns over another fuel, ethanol, that has also seen a spate of accidents as production has increased. It also leaves out tens of thousands of flawed tank cars that carry crude and ethanol and are known to split open during derailments. Railroads and federal officials said they would address that issue separately.
By taking voluntary steps, railroads will be able to act far more quickly than if they waited for new safety rules to be drafted and approved by the government, said Robert Chipkevich, former director of rail and hazardous materials accident investigations at the National Transportation Safety Board.
But he added that regulators will have little leverage to enforce the industry’s commitments.
‘‘It’s a positive step,’’ Chipkevich said. ‘‘But certainly there’s nothing to say they would have to continue following those practices. The only way you can enforce something like that would be for regulators to publish regulations and do periodic oversight.’’
Federal officials said they would continue to pursue longer-term measures to further improve safety. They also said they would use regular inspections to check for compliance with the agreement.
With no formal rules, inspectors would be unable to issue fines or take other punitive measures for failing to live up to the agreement.
‘‘We expect for this to be a document that is fully adhered to, and are prepared to inspect accordingly and call out the industry as necessary,’’ Federal Railroad Administrator Joseph Szabo said in an interview.
The Association of American Railroads represents all of the major railroads in the United States, Canada, and Mexico, and president Edward Hamberger said he expects all of them to sign on to the agreement.
At least 10 times since 2008, freight trains hauling oil across North America have derailed and spilled significant quantities of crude, with most of the accidents touching off fires or catastrophic explosions.
The deadliest wreck killed 47 people in the town of Lac-Megantic, Quebec. Others have occurred in rural areas of North Dakota, Alabama, Oklahoma, and New Brunswick. The derailments released almost 3 million gallons of oil, nearly twice as much as the largest pipeline spill in the United States since at least 1986.
Under the agreement, railroads also would have to weigh the risks along particular routes and consider alternatives, although specialists say it’s inevitable the trains would continue going through population centers.
The railroads agreed to provide $5 million to develop a training curriculum for emergency responders tailored to crude oil accidents.
Since 2008, the number of tanker cars hauling oil has increased 40-fold, and federal records show that’s been accompanied by a dramatic spike in accidental crude releases from tank cars.