WASHINGTON – Last week, U.S. Sen. Al Franken asked the Federal Railroad Administration to consider rerouting trains carrying volatile Bakken crude oil from North Dakota so they do not pass through Minnesota's biggest cities.

For Franken, the possibility of rerouting is an integral part of a comprehensive response to a recent rash of fiery oil train derailments that also includes stabilizing Bakken crude before it is loaded into stronger tanker cars.

For the nation's powerful railroad lobby, however, rerouting is an unwarranted intrusion into a rail safety system that the industry says works.

Government-ordered rerouting of private rail traffic is not exactly a snowball in hell. It is more like a blizzard in Bahrain — possible, but unprecedented.

In Minnesota and around the country, "rerouting issues ought to be high on everyone's agenda," said rail safety expert Fred Millar, who fought unsuccessfully against railroads to move chlorine trains out of the District of Columbia. "But rerouting has been pushed off the table."

Congress created the Federal Railroad Administration in 1966. In nearly half a century it does not appear to have forced any railroads to reroute trains around big cities for safety reasons, despite computer modeling that estimates routing changes could lower citizens' risks to hazardous materials derailments by 25 to 50 percent and reduce casualties in an actual derailment by half.

The Minnesota Department of Transportation (MnDOT) last week estimated that 326,170 state residents live within a half-mile of rail routes that carry oil from North Dakota across Minnesota. A half-mile is the federal emergency response evacuation zone required in the event of a single tanker car spill and fire. Multiple-car fires require up to a mile evacuation.

MnDOT data shows that 156,316 of the Minnesotans subject to evacuation in an oil train derailment live in the Twin Cities metro area. Most North Dakota oil trains enter Minnesota at Moorhead, then travel on BNSF Railway and Canadian Pacific Railway tracks into the Twin Cities before turning south along the Mississippi River and east across Wisconsin. A few oil trains travel through western Minnesota into Iowa.

Although the National Transportation Safety Board has backed rerouting in some circumstances, federal laws passed in 2007 grant private rail companies wide latitude in determining when and where trains should move, even trains carrying hazardous materials.

Canadian Pacific did not comment specifically on rerouting trains in Minnesota, but in an e-mail to the Star Tribune, the railroad said it has voluntarily complied with the federal government's Crude by Rail Safety Initiatives and performed "route risk assessments."

BNSF, the largest crude-by-rail hauler out of North Dakota, declined to comment on rerouting and referred questions to the rail industry's major trade group, the Association of American Railroads.

An AAR spokesman said the industry opposes re-routing oil trains because the existing routes are the safest, even when they pass through urban areas. The industry supports more structurally secure tanker cars, track inspections and training of emergency response teams, said AAR media relations director Ed Greenberg.

BNSF also has invested heavily in track improvements to increase safety along its existing Minnesota oil train routes.

"We're using routing technology called the Rail Corridor Risk Management System developed by the federal government," Greenberg said. The technology measures 27 factors — including population density — to determine the safest route for moving hazardous materials, including crude oil, Greenberg said.

"Rerouting isn't the answer," he maintained. "All it has accomplished in the past is to force rail traffic through other communities on tracks not built to accommodate products like crude oil."

The Federal Railroad Administration declined to discuss rerouting oil trains in Minnesota. In an e-mail statement, acting administrator Sarah Feinberg said of Franken's request: "Over the past 18 months we have taken more than a dozen actions to enhance the safe transport of crude oil while working on a comprehensive rule that is now in its final stages of development."

The state has little say in the rerouting debate. "The railroads are regulated by the federal government," Minnesota Department of Transportation spokesman Kevin Gutknecht said. "The state does not have the authority to move, or reroute, rail lines."

Rerouting trains away from the Twin Cities is not part of a rail safety initiative unveiled March 13 by Gov. Mark Dayton. That proposal calls for spending $330 million over 10 years, much of it in greater Minnesota, mainly to make road-rail crossings safer and to improve emergency response.

Still, the potential consequences of oil train derailments in the Twin Cities are considerable.

Oil trains across Minnesota are expected to persist, and possibly increase if North Dakota resumes its oil boom. A Minnesota Environmental Quality Board draft study released last week projected that by 2024, the state could see more than 11 oil trains daily, each with 110 tank cars carrying a total of 3.3 million gallons of volatile light crude. Currently about six or seven such trains cross Minnesota each day.

Meanwhile, said rail safety expert Millar, "imagine trying to evacuate half a mile of Minneapolis or St. Paul."

There have been four oil train derailments in the U.S. and Canada since mid-February.

"We've seen lots of derailments and explosions now," said Franken, citing a 2013 accident in Quebec that killed 47 people and a fiery crash in Illinois earlier this month that overwhelmed firefighters. "If that's going to happen, it would be better if it happened away from a populated area."

Franken said he has been hearing from many Minnesota "first responders and city officials who have a tremendous amount of concern about what they'll be able to do" in the event of a derailment. "They tell me the population centers are the biggest problem."

The benefits of rerouting hazardous materials trains around urban areas has not been widely studied. A 1983 paper published by one of the leading researchers, Ted Glickman of George Washington University, reported that "population exposure can be reduced 25 to 50 percent by rerouting" and that "extensive routing changes can reduce casualties by about 50 percent, but … extensive upgrading with or without rerouting can be even more effective."

The railroad association's Greenberg said he could not speculate on what the damage might be if an oil train passing through the Twin Cities derailed.

Millar predicted potentially big problems, based on a slow-speed derailment in West Virginia in February that burned out of control as firefighters watched from a distance. The tanker cars that leaked and caused the fire were newly designed to resist spilling.

The existing rail system in Minnesota offers limited alternatives to moving Bakken crude through the Twin Cities, Rochester and Duluth. BNSF runs some oil trains through Fargo and down the western edge of the state to Iowa. But whether it is economical or practical to reroute oil trains away from the state's biggest cities is not clear.

"If you're going to reroute everything, you create efficiency problems," said Mark Rosenker, a former chairman of the National Transportation Safety Board, who now runs the Transportation Safety Group consultancy.

Rosenker believes better stabilization of Bakken oil, stronger tanker cars, slower speeds and computerized controls on engines are more practical alternatives. Still, explosions and fires like those that accompanied the West Virginia derailment give him pause.

The train was traveling well below the maximum speed, carrying oil in newly reinforced cars. But when it left the tracks, a fiery disaster ensued that thwarted firefighters, forced evacuations, poured oil into a nearby river and burned one home to the ground.

"That surprised me," Rosenker said. "It was just an ordinary derailment. The expectation is that it would have been survivable. We may have to go back to the drawing board."

In Minnesota, Dayton's rail safety package includes $50 million for a project that, in part, would construct new tracks west of Willmar, to reroute about half the train traffic around that city of 19,600 people. The city, home to a BNSF rail yard, has seen an uptick in freight traffic of all types, including oil trains.

Willmar Mayor Marv Calvin said that shifting some of that city's rail traffic to a rural bypass would enhance safety by reducing trains passing through the city. The project requires approval of the Legislature, which would need to issue state-backed bonds.

Calvin, a former fire chief, said any shift of rail traffic away from the Twin Cities likely would affect some other part of the state.

"If something happens with a Bakken train, it will be a catastrophe — that is not in question," Calvin said. "If it happens in downtown Willmar it will be bad. If it happens in downtown Minneapolis it will be bad."

Staff writer David Shaffer contributed to this report.

Jim Spencer • 202-383-6123