PHMSA is issuing a final rule to codify certain mandates and minimum requirements set forth by the Fixing America’s Surface Transportation Act of 2015 (FAST Act). Specifically, the FAST Act mandates a new phase-out schedule for DOT-111 specification tank cars, including DOT-111 tank cars constructed to the Casualty Prevention Circular (CPC) 1232 (CPC-1232) industry standard, used to transport unrefined petroleum products e.g., petroleum crude oil, ethanol, and other Class 3 flammable liquids, irrespective of train composition. In addition, the FAST Act mandates that each tank car built to meet the DOT-117 specification, and each non-jacketed tank car retrofit to meet the DOT-117R specification, be equipped with an insulating blanket with at least -inch-thick material that has been approved by the Secretary pursuant to 49 CFR 179.18(c). Moreover, the FAST Act specifies minimum top fittings protection requirements for tank cars retrofit to meet the DOT-117R specification. Because the actions taken in this final rule address congressional mandates that instruct the Secretary to issue conforming regulatory amendments immediately or soon after the FAST Act’s date of enactment, PHMSA finds that due and timely execution of agency functions would be impeded by the procedures of public notice that are normally required by the Administrative Procedure Act (APA). Therefore, PHMSA finds that public notice is impracticable and that good cause exists to amend the regulations without advance notice and opportunity for public comment.