The Transportation Safety Board of Canada is urging U.S. and Canadian regulators to improve the accuracy of documentation for hazardous materials shipped via rail. The U.S. Pipeline and Hazardous Materials Safety Administration is among the recipients of the letter. The U.S. National Transportation Safety Board released a statement last week that said, "We share the TSB's concern. Clearly understanding the hazardous characteristics of what is being transported is one of the keys to safe transportation."