Every day, as many as 10 oil trains leave North Dakota, and six to eight of them travel through Minnesota on their way to posts on Lake Superior and points south.
They pass through places like Perham, a town of 3,000 about 65 miles southeast of the Fargo-Moorhead area, in the heart of lakes country.
The town may be small, but it is bustling with activity. On one side of the railroad tracks are the shops that draw summer tourists. On the other side are industrial buildings that turn out potato chips, candy, dog food and cheese.
Around the clock, semitrailers rumble across the Burlington Northern Santa Fe mainline railroad tracks to and from the factories. Last year, trains hit trucks crossing the tracks three times.
It's not unusual to see trucks try to beat the trains, even on crossings that have warning lights and stop arms, Perham Mayor Tim Meehl said.
"The fire chief was telling me he walked out of here and a semi tried to beat the train the other day," Meehl said. "He made it, but the arms actually hit the side of the trailer as he went through."
Although none of those trains derailed last year, trains have derailed four times in Perham since 1992, according to federal records. In the most recent derailment, in 2003, seven cars left the tracks and plowed into a candy factory.
Given the never-ending rail traffic, local officials fear that it will happen again, with dangerous results.
In 2011, railroads hauled 66,000 carloads of crude from the Bakken oil fields of North Dakota. Last year, they carried 400,000 carloads. With so much crude moving over the rails, federal officials are also concerned. That's prompting government agencies and the railroads to consider more efforts to ensure safety, including safer tank cars and more rail inspectors. There's also a push to improve safety at rail crossings.
Trains don't have to slow down going through Perham or most Minnesota cities and towns. Meehl, a 19-year veteran of the volunteer fire department, worries what could happen if an oil train traveling 50 miles per hour hits a loaded truck and derails. From 1992 to 2013, there have been 18 rail crossing accidents.
"Well if it happened right out there, this place would probably fry," he said. "All of our vehicles would be gone. Yeah, it's scary, but life goes on."
Meehl said local firefighters are well trained, but the most important public facilities, the fire station and City Hall are vulnerable to a catastrophic accident.
"All of our emergency operations [locations] are sitting right along the railroad track," he said. "Our number one is upstairs, our number two is in City Hall and that's right along the railroad tracks too. So I said to the city manager, 'You ever think we maybe should get an option three?'"
"I mean, just talking about this oil, you know you laugh about it," Meehl said. "But I guess you just pray it doesn't happen here."
Nationally, there are fewer train derailments than 10 or 20 years ago, according to federal statistics, which show a steady improvement in rail safety.
Last year, the BNSF railroad recorded the fewest mainline derailments in its history, company officials say. BNSF will invest a record $5 billion in infrastructure this year, including $900 million along its northern corridor where much of the oil travels.
Amy McBeth, a spokeswoman for the railroad, said all major causes of derailment decreased in the past 10 years. Derailments caused by equipment failure are down 54 percent, derailments caused by human error declined 42 percent and there were 34 percent fewer derailments caused by track defects.
But high-profile accidents with trains hauling North Dakota crude are raising new concerns. Federal regulators warn that Bakken crude is more volatile than other crude oils. A recent Canadian investigation compared the light crude oil to unleaded gasoline.
The National Transportation Safety Board calls the rail tank cars now in use an "unacceptable public risk." The federal transportation department is working on new safety standards for oil tank cars that haven't been improved in decades.
"So they're arguing about who's going to spend the money and how fast to phase in the new car design," University of North Dakota mechanical engineering professor George Bibel said.
Bibel, who recently wrote a book on the forensics of train wrecks, said adopting new safety standards is a complex process that comes down to a cost benefit-analysis in which experts weigh the cost of accidents against the cost of safety.
"They'll look at everything. They'll look at environmental damage, equipment damage, and human life and injury and put prices on injuries and fatalities," Bibel said. "We kill about 34,000 people a year in cars. You could reduce that by 99 percent if we all drive $2 million safety-enhanced cars. So it's always that kind of trade-off."
Bibel said new tank car designs will improve safety, but not eliminate the risk of hauling volatile crude oil.
"It'll make it better, but a 100-car train derails at 40 miles per hour. It's more than likely still going to split a car or two open," he said.
It could take years to replace the existing tanker fleet.
There are currently 92,000 tank cars approved for hauling hazardous flammable liquids, said Minnesota State University Moorhead Associate Professor Paul Sando, who is studying the logistics of rail traffic.
"If they go to the latest DOT standards for safety, immediately 78,000 of those would be obsolete, three-quarters of the fleet obsolete over night," Sando said. "Nobody is willing to do that because it would bring everything to a screeching halt."
Even before new regulations are released, orders for new safer tank cars are overwhelming manufacturers. Industry experts say factories are two years behind on orders.
BNSF recently took the unusual step of announcing it would order 5,000 of the new safer tank cars. As railroads typically don't own the cars they pull, it's a sign the railroad is very concerned about safety and liability, Sando said.
"For BNSF to commit to 5,000 tank cars, this is a big deal," he said. "This is good business and a good PR move for BNSF. They're saying we realize this is going to be around for a while and we want these cars to be as safe as possible."
Sando said the rail car manufacturers aren't likely to catch up with demand any time soon. When new federal rules are approved, some existing tank cars might have safety shields and rollover protection added. But experts say it's likely many of the older cars will be scrapped.
Whatever type of car is hauling hazardous material, Minnesota state officials have a renewed interest in keeping those cars on the tracks.
Bill Gardner, director of the office of freight and commercial vehicle operations for the Minnesota Department of Transportation, said mile-long trains loaded with volatile Bakken crude raise the stakes in any accident.
The state has one rail inspector who works with two federal inspectors in Minnesota.
A recent General Accounting Office report found federal inspectors check only about one percent of regulated rail activity each year. Inspectors specialize in track, equipment, signals, hazardous materials or railroad operations.
But Gardner said the government largely depends on railroads to keep the tracks safe.
"Certainly they have the primary responsibility and they are doing most of the inspections and they say that they're doing more than what's actually required particularly on these key oil train routes," he said.
BNSF officials say crude oil routes are inspected four times a week, twice as often as federal regulations require.
Railroad officials declined a request for an interview about inspections, but in an email said BNSF has 600 inspectors working on its rail system. The railroad is increasing its use of technology, including ultrasonic scans to look for flaws inside steel rails, rail cars equipped with lasers and computers to check track alignment and wear and ground penetrating radar to identify weak spots in soil under the tracks.
Gardner said the state will consider hiring more track inspectors and perhaps a hazardous materials inspector.
MnDOT also is taking a new look at rail crossing safety. Federal records show 53 rail crossing accidents in Minnesota last year.
Gardner said on crude oil routes, most Twin Cities metro area crossings already have signals and stop arms. But across the state there are 112 crossings on oil routes that have only a stop sign.
He said MnDOT is developing new risk criteria to identify the most dangerous crossings. Among the factors it might consider are whether schools, nursing homes or populated areas are near crossings and how many trucks cross the tracks.
Federal and local officials along with railroads will be part of the safety review.
Gardner said the agency might close some crossings, and upgrade others with signals.
"We're trying to settle on a timeframe for doing this but we would certainly want to do this sooner than later and try do it as expeditiously as possible," he said. "I can't say how quickly we could complete this but certainly it would be a priority."
It costs about $275,000 to add signals and safety arms to one crossing, Gardner said. The state receives about $5 million a year in federal funding for rail crossing projects.
The question for policy makers deciding to invest more money in rail safety is, how long will railroads be the pipeline moving Bakken crude to refineries?
Some investors are betting on the long haul. They include Neal Amondson, who co-founded Northstar Transloading two years ago with Minneapolis-based Hempel Companies.
Later this year they plan to open the largest oil train loading facility in North Dakota. Amondson said the $100 million operation will load four oil trains a day.
"We expect a minimum of 20 years, maybe 40," he said. "But anytime you make a prediction beyond five years you're maybe out-predicting yourself. We certainly see it for the long haul."