Liquefied natural gas (LNG) has not been transported to any significant degree by freight railroads in the United States. When the Further Consolidated Appropriations Act of 2020 was enacted, it directed the Pipeline and Hazardous Materials Safety Administration (PHMSA) to enter into an agreement with the National Academies of Sciences, Engineering, and Medicine (NASEM) to convene a committee of independent experts to study the safe transportation of LNG by rail tank car. TRB Special Report 339: Preparing for LNG by Rail Tank Car: A Review of a U.S. DOT Safety Research, Testing, and Analysis Initiative, from TRB and NASEM, finds that PHMSA's task force presented a comprehensive plan of work that built on longstanding safety programs, as well as surfacing opportunities for future research. The findings in the report will serve as a good base for the second phase of TRB's phased continued study of the issue. The next phase will be informed by this technical report; will consider experience transporting LNG in other modes, including marine tankers and cargo tank trucks; and will examine the applicability of existing emergency response plans, protocols, and guides for responding to any possible hazardous materials incidents of transporting LNG by rail.

Shipping liquefied natural gas (LNG) by rail tank car is a viable mode in U.S. regions where the natural gas pipeline network is limited. Before the first bulk shipment of LNG by rail tank car, the National Academies of Sciences, Engineering, and Medicine recommends a review of the research and testing done so far on safety assurance, especially for the design of the tank car, and follow up with activities if warranted. The pre-publication draft of TRB Special Report 345: Preparing for LNG by Rail Tank Car: A Readiness Review, from TRB and NASEM, focuses on safe train operations, support for emergency responders, and design features of the new cryogenic tank car, including pressure relief devices, insulation, and the type of outer tank steel.