Under pressure from Congress, NTSB, and the public to take regulatory action in light of recent accidents involving oil trains, PHMSA finalized its regulations applicable to “High-Hazard Flammable Trains” in a Final Rule (the Rule) issued a mere nine months after it was proposed in an August 1, 2014 Notice of Proposed Rulemaking (NPRM).  The Rule amends PHMSA’s hazardous materials regulations at 49 C.F.R. Parts 171 – 180, incorporating numerous NTSB recommendations on rail safety as well as input from stakeholders.  Among the main features of the Rule are enhanced standards for new tank cars and an aggressive retrofitting schedule for older tank cars transporting crude oil and ethanol.  It creates operational protocols for trains transporting large amounts of flammable liquids, as well as new sampling and testing requirements intended to improve classification of unrefined petroleum products offered for transportation.  The new standards were developed in coordination with Canadian transportation safety officials, in recognition of the fact that oil trains moving product across the international border “are part of a North American fleet and a shared safety challenge.”

Numerous commenters weighed in on the proposed standards during the rulemaking process.  As reflected below, the Rule reflects an ambitious attempt on the part of the Agency to address potential hazards from crude oil and ethanol transportation by rail, an approach likely influenced by the high profile and dramatic nature of recent incidents.  It contains several components, all designed to “reduce the consequences and, in some instances, reduce the probability of accidents involving trains transporting large quantities of flammable liquids.”  Given the magnitude of the rule, there is a strong likelihood that it may be challenged even while the regulated community proceeds with voluntary efforts to achieve compliance.    


The  Rule defines “high-hazard flammable train” (HHFT) to mean a single train transporting 20 or more loaded tank cars of a Class 3 flammable liquid in a continuous block or a single train carrying 35 or more loaded tank cars of a Class 3 flammable across the entire train.  49 C.F.R. Part 171.8.  For the purposes of the enhanced braking systems requirement in the Rule, it separately defines “high-hazard flammable unit train” (HHFUT) to mean a single train transporting 70 or more loaded tank cars containing Class 3 flammable liquid. Id.

The HHFT definition in the Rule builds upon the definition originally proposed (which was limited to trains transporting 20 or more cars with Class 3 flammable liquids in a continuous block) in order to capture single-commodity “unit” trains, while excluding lower-risk manifest trainsMany comments on the NPRM concerned the threshold number of cars for HHFT designation.  Some environmental groups and other stakeholders suggested a threshold as low as one car for HHFT designation; NTSB, for example, supported a single tank car approach with regard to tank car specifications and retrofits.  The Rule ultimately rejects this approach in favor of a focus on higher risks associated with bulk shipments, i.e. those trains with large blocks of flammable liquids, such as crude oil and ethanol.

Tank Car Standards

New tank cars constructed after October 1, 2015, are required to meet new prescriptive standards for DOT Specification 117 (DOT-117) design or performance standards that are DOT-117 equivalent.  The new specifications mandate a 9/16 inch tank shell, 11 gauge jacket, 1/2 inch full-height head shield, thermal protection, and improved pressure relief valves, bottom outlet valves and top fittings.  This standard is a modified version of Tank Car Option 2 set forth in the NPRM, and was chosen based upon broad support from commenters (with the exception of the 9/16 inch tank shell, which many commenters did not favor) and its perceived benefits in light of its costs.

Existing tank cars must be retrofitted with the same components based on a prescriptive, risk-based retrofit schedule; specifically, the Rule requires replacing the entire fleet of DOT-111 tank cars for Packing Group I (which covers most crude shipped by rail) within approximately 3 years and all non-jacketed CPC-1232s carrying Packing Group I materials within approximately 5 years.  Longer timeframes are prescribed for tank cars in Packing Group II and III service, with the entire fleet of DOT-111 and CPC-1232 cars to be retrofitted within 10 years.  This retrofit timeline modifies the approach in the NPRM (which focused on a single risk factor, packing group) to account for both packing group and type of tank car.

Operational Requirements

Trains transporting large volumes of flammable liquids will be required to observe new operational protocols, including braking specifications, routing requirements, speed restrictions, and information-sharing with State and local government agencies.


The Rule sets forth new braking standards for both HHFTs and HHFUTs, the purpose of which is to reduce the severity of accidents and  the “pile-up effect.”  HHFTs must have in place a functioning two-way end-of-train (EOT) device or a distributed power (DP) braking system.  HHFUTs transporting one or more tank cars loaded with a Packing Group I flammable liquid must have an electronically controlled pneumatic (ECP) braking system by January 1, 2021 (with the requirement for all other HHFUTs to have ECP braking systems taking effect May 1, 2023).

Speed restrictions

HHFTs are restricted to 50 mph in all areas, and HHFTs containing any tank cars not meeting the Rule’s new tank car standards are restricted to 40 mph speed in high-threat urban areas (a 40 mph speed restriction for HHFTs without new or retrofitted tank cars is currently mandated by FRA’s Emergency Order No. 30 (Aug. 5, 2013)).

Rail Routing

Risk Assessment—Rail carriers operating HHFTs must perform a detailed routing analysis, with baseline consideration of the numerous safety and security factors set forth in 49 C.F.R. Part 172, Appendix D, and select a route based on its findings.

Notifications—Carriers must provide certain State, local, and tribal officials with a railroad point of contact for information related to the routing of hazardous materials through their jurisdictions.


Offerors of unrefined petroleum-based products must accurately classify and describe their products in accordance with a sampling and testing program, which specifies various criteria related to sampling frequency and methodology.  They must also certify that hazardous materials subject to the testing and sampling program are packaged in accordance with test results, document program outcomes, and make this information available to DOT upon request.


Most industry comments on the proposed rule cited concerns about the costs of compliance with the new specifications, standards, and procedures, particularly in relation to their anticipated safety benefits.  According to PHMSA, the Final Rule reflects a balancing of costs and benefits to arrive at the most cost-effective, risk-based means of achieving improved safety of oil and ethanol rail transportation.  In addition, the Agency acknowledges the substantial capital investment that will be required to retrofit existing cars and manufacture new cars, citing this as a principal reason for harmonizing the new requirements with Canadian standards to the extent possible.

Whether the Rule strikes a proper balance of costs and benefits remains to be seen, and consequences of the Rule on various aspects of the transportation of energy products (including shop capacity to produce new tank cars and retrofit existing ones to the new standards, as well as impacts on rail congestion) will also bear out in the coming months as shippers and carriers prepare for the new standards to go into effect.  The Rule takes effect July 7, 2015.