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49 CFR § 174.310 - Requirements for the operation of high-hazard flammable trains.

---
identifier: "/us/cfr/t49/s174.310"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 174.310 - Requirements for the operation of high-hazard flammable trains."
title_number: 49
title_name: "Transportation"
section_number: "174.310"
section_name: "Requirements for the operation of high-hazard flammable trains."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "HAZARDOUS MATERIALS REGULATIONS"
part_number: "174"
part_name: "CARRIAGE BY RAIL"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5101-5128; 33 U.S.C. 1321; 49 CFR 1.81 and 1.97."
cfr_part: "174"
---

# 174.310 Requirements for the operation of high-hazard flammable trains.

(a) *Applicability.* Each rail carrier operating a high-hazard flammable train (as defined in § 171.8 of this subchapter) must comply with each of the following additional safety requirements with respect to each high-hazard flammable train that it operates:

(1) *Routing.* The additional planning requirements for transportation by rail in accordance with part 172, subpart I of this subchapter.

(2) *Speed restrictions.* All trains are limited to a maximum speed of 50 mph. The train is further limited to a maximum speed of 40 mph while that train travels within the limits of high-threat urban areas (HTUAs) as defined in § 1580.3 of this title, unless all tank cars containing a Class 3 flammable liquid meet or exceed the DOT Specification 117 standards, the DOT Specification 117P performance standards, or the DOT Specification 117R retrofit standards provided in part 179, subpart D of this subchapter.

(3) *Braking.* Each rail carrier operating a high-hazard flammable train (as defined in § 171.8 of this subchapter) operating at a speed in excess of 30 mph must ensure the train is equipped and operated with either a two-way end-of-train (EOT) device, as defined in 49 CFR 232.5, or a distributed power (DP) system, as defined in 49 CFR 229.5.

(4) *New tank cars.* After October 1, 2015, tank cars manufactured for use in a HHFT must meet:

(i) DOT Specification 117, or 117P performance standard in part 179, subpart D of this subchapter; or

(ii) An authorized tank specification as specified in part 173, subpart F of this subchapter.

(5) *Retrofit reporting.* Owners of non-jacketed DOT-111 tank cars in PG I service in an HHFT, who are unable to meet the January 1, 2017, retrofit deadline specified in § 173.243(a)(1) of this subchapter are required to submit a report by March 1, 2017, to Department of Transportation. A group representing owners may submit a consolidated report to the Department of Transportation in lieu of individual reports from each tank car owner. The report must include the following information regarding the retrofitting progress:

(i) The total number of tank cars retrofitted to meet the DOT-117R specification;

(ii) The total number of tank cars built or retrofitted to meet the DOT-117P specification;

(iii) The total number of DOT-111 tank cars (including those built to CPC-1232 industry standard) that have not been modified;

(iv) The total number of tank cars built to meet the DOT-117 specification; and

(v) Entities required to submit a report under this paragraph shall submit subsequent follow-up reports containing the information identified in this paragraph within 60 days of being notified by PHMSA and FRA.

(6) *Oil spill response plans.* The additional requirements for petroleum oil transported by rail in accordance with part 130 of of this chapter.

(7) *High-hazard flammable train (HHFT) information sharing notification for emergency response planning.* The additional requirements for notification in § 174.312.

(b) [Reserved]

[80 FR 26748, May 8, 2015, as amended at 83 FR 48401, Sept. 25, 2018; 84 FR 6952, Feb. 28, 2019]