National Public Radio: North Dakota and western Canada are producing crude oil faster than it can be shipped to refineries. Rail car manufacturers can't make new tank cars fast enough, and new pipeline proposals face long delays over environmental concerns. So energy companies are looking for new ways to get the heavy crude to market. One proposed solution is to ship the oil by barge over the Great Lakes but it's a controversial one. Crews are working around the clock in North Dakota, where there's a lot of oil under...