Full Opinion

USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 1 of 93 FOR PUBLICATION In the United States Court of Appeals For the Eleventh Circuit ____________________ No. 24-11076 ____________________ FLORIDA EAST COAST RAILWAY LLC, Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, UNITED STATES DEPARTMENT OF TRANSPORTATION, Respondents, INTERNATIONAL ASSOCIATION OF SHEET METAL, AIR, RAIL AND TRANSPORTATION WORKERS- TRANSPORTATION DIVISION Intervenor. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 2 of 93 2 Opinion of the Court 24-11076 ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-11300 ____________________ TEXAS & NORTHERN RAILWAY COMPANY, Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-11366 ____________________ ASSOCIATION OF AMERICAN RAILROADS, USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 3 of 93 24-11076 Opinion of the Court 3 Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-11367 ____________________ AMERICAN SHORT LINE AND REGIONAL RAILROAD ASSOCIATION, Petitioner versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 4 of 93 4 Opinion of the Court 24-11076 Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-11428 ____________________ INDIANA RAIL ROAD COMPANY, Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 5 of 93 24-11076 Opinion of the Court 5 ____________________ No. 24-11444 ____________________ UNION PACIFIC RAILROAD CO., Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-11445 ____________________ NEBRASKA CENTRAL RAILROAD COMPANY, Petitioner, versus USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 6 of 93 6 Opinion of the Court 24-11076 FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ ____________________ No. 24-12003 ____________________ BNSF RAILWAY COMPANY, Petitioner, versus FEDERAL RAILROAD ADMINISTRATION, ADMINISTRATOR, FEDERAL RAILROAD ADMINISTRATION, U.S. DEPARTMENT OF TRANSPORTATION, Respondents. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 7 of 93 24-11076 Opinion of the Court 7 ____________________ Petitions for Review of a Decision of the Federal Railroad Administration Agency No. FRA-2021-0032 ____________________ Before ROSENBAUM, BRANCH, and KIDD, Circuit Judges. ROSENBAUM, Circuit Judge: It’s hard to tell the United States’s story without dedicating a long chapter to the railroad. Back in 1869, the Transcontinental Railroad tied together a disparate country in a new way. Today, rail continues to play a critical role in transporting people and goods. But like all forms of transportation, trains have posed some safety concerns from the beginning. The “Angola Horror” of De- cember 1867 drove a wave of safety reforms after some 50 people died in a train derailment and fire in New York. 1 And on occasion, unfortunately, train accidents continue to happen today. 2 Still, technology has helped. Yet as technology has evolved, railroads have moved towards using smaller and smaller train crews. So in recent years, the Federal Railroad Administration 1 Rich Kellman, The Angola Horror of 1867; Train Crash Led to Rail Safety, BUFFALO TORONTO PUB. MEDIA (Jan. 4, 2011), https://www.btpm.org/2011- 01-04/the-angola-horror-of-1867-train-crash-led-to-rail-safety [https://perma.cc/R5ER-MAX9]. 2 See, e.g., Peter Eavis, Since Ohio Train Derailment, Accidents Have Gone Up, Not Down, N.Y. TIMES (Jan. 28, 2024), https://www.ny- times.com/2024/01/28/business/ohio-train-derailment-safety-east-pales- tine.html [https://perma.cc/QP8J-Y8LY]. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 8 of 93 8 Opinion of the Court 24-11076 (“FRA”) has fielded concerns that some railroads’ shift towards one- person train crews could pose safety risks. In 2024, the FRA issued the regulation that sparked this case. See 89 Fed. Reg. 25052 (Apr. 9, 2024). That regulation, the “Crew Size Rule” or “Rule,” requires railroads to operate with at least two crewmembers on board unless using a one-person crew would be at least as safe. Some parts of the rail industry dislike this new requirement. Six railroads and two industry trade organizations (“Petitioners” or “Railroads”) filed petitions for review of the FRA’s rulemaking. We consolidated those petitions in this Court. The Railroads assert that the FRA violated the Administra- tive Procedure Act by exceeding its statutory authority and acting arbitrarily and capriciously in several ways. One group of petition- ers, representing the interests of larger railroads, raises five issues. A second group, representing smaller railroads, raises another two. We address these concerns below. But because none of the Railroads’ arguments have merit, we deny their petitions. I. BACKGROUND A. Regulation of Railroad Safety The Secretary of Transportation holds broad power to issue regulations to promote railroad safety. The Federal Railroad Safety Act of 1970, as amended, authorizes that power. It provides, “The Secretary of Transportation, as necessary, shall prescribe USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 9 of 93 24-11076 Opinion of the Court 9 regulations and issue orders for every area of railroad safety.” 49 U.S.C. § 20103(a). The Secretary delegated this authority to the Administrator of the FRA, an agency within the U.S. Department of Transportation. 49 C.F.R. § 1.89(a). Under that delegation, the FRA has issued a wide range of safety regulations. These rules address, for example, track inspec- tions, Id. § 213.233; qualification of locomotive engineers and train conductors, id. pts. 240, 242; locomotives’ braking systems, id. § 229.13; random drug and alcohol testing of railroad employees, id. § 219.603; and track switches, id. § 213.135. B. Past Regulatory Attention to Train Crew Size Technological changes have allowed railroads to shrink their average crew size over time. The number of crewmembers on each train has dropped from around five in the 1960s to two in the 1990s. See 87 Fed. Reg. 45564, 45567 col.1 (July 28, 2022). Today, most railroad operations use at least a two-person crew, consisting of a locomotive engineer and a conductor. Id. at 45578 col.1. The locomotive engineer performs nearly all actions that control the movement of a train. Id. At the same time, the conductor leads the train crew as a whole, managing the train con- sist (the cars that make up the train), interacting with dispatchers and others outside the train cab, and dealing with unusual situa- tions like mechanical problems. Id. at 45567 col.3–45568 col.1. In recent years, though, more railroads have started operat- ing with a one-person crew. See id. at 45578 col.2. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 10 of 93 10 Opinion of the Court 24-11076 Before the Crew Size Rule, no regulation specifically regu- lated minimum crew size. Yet the seeds for that regulation were planted more than a decade earlier. Regulatory attention to one-person crews spiked after a cat- astrophic accident in Quebec, Canada, in July 2013. A train with a one-person crew saw numerous crude-oil tank cars derail at the town of Lac-Mégantic. See 87 Fed. Reg. at 45568 col.3–45569 col.1. The ensuing explosions and fires caused 47 fatalities and required 2,000 people to evacuate the surrounding areas. See id. The FRA wasted no time trying to prevent something simi- lar from happening here. The next month, in August 2013, the FRA directed the Railroad Safety Advisory Committee to “review whether train crew staffing practices affect railroad safety.” See 81 Fed. Reg. 13918, 13936 col.2 (Mar. 15, 2016). But while that com- mittee conducted its review, another major accident occurred, this time in Casselton, North Dakota. There, a multimember crew took “heroic actions” to prevent a crude-oil fire from spiraling out of control after a crude-oil train collided with a derailed “grain train.” Id. at 13923 col.2–13924 col.3. The committee’s working group did not reach consensus on recommendations by the April 1, 2014, deadline. Id. at 13939 col.1. Two years later, in March 2016, the FRA started a rulemak- ing proceeding to regulate crew size. Id. at 13918 col.1. The notice of proposed regulation (“2016 Notice”) described a rule that would have generally required trains to operate with at least two crew- members, with exceptions for “operations that FRA believes do not USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 11 of 93 24-11076 Opinion of the Court 11 pose significant safety risks . . . by using fewer than two-person crews.” Id. The 2016 Notice contemplated exceptions for most railroads that had already used one-person crews since before 2015. Id. at 13964 col.2–13966 col.3. It also considered options for allow- ing railroads to start new one-person operations after submitting certain information to the FRA, with agency approval required in some instances. See id. In 2019, the FRA withdrew the 2016 Notice. 84 Fed. Reg. 24735 (May 29, 2019) (“Withdrawal Order”). The agency explained its view that a crew-size rule was unwarranted because “FRA’s ac- cident/incident safety data does not establish that one-person op- erations are less safe than multi-person train crews.” Id. at 24739 col.2. Besides declining to issue a crew-size regulation, the With- drawal Order also purported to “negatively preempt any state laws” requiring a minimum number of crewmembers. Id. at 24741 col.3. In 2021, the U.S. Court of Appeals for the Ninth Circuit va- cated the Withdrawal Order and remanded to the FRA. Transp. Div. of the Int’l Ass’n of Sheet Metal, Air, Rail, & Transp. Workers v. Fed. R.R. Admin. (SMART-TD I), 988 F.3d 1170 (9th Cir. 2021). The court reasoned that the Withdrawal Order was, in effect, a nation- wide one-person crew rule. Id. at 1182. Among other flaws, the court held that a one-person crew-size mandate was not a “logical outgrowth” of the initial proposal. Id. at 1180–81. The court also questioned the Withdrawal Order’s reasoning. Id. at 1182. As the Ninth Circuit saw things, the FRA “fail[ed] to address the multiple USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 12 of 93 12 Opinion of the Court 24-11076 safety concerns” that the majority of commenters raised and of- fered “no safety or economic justification for preemption” of state minimum-crew-size rules. Id. at 1183–84. C. The 2024 Crew Size Rule In July 2022, the FRA published a notice of proposed rule- making (“2022 Notice”) on a rule that would regulate crew size. 87 Fed. Reg. 45564 (July 28, 2022). During a 146-day comment period, the FRA received around 13,500 comments from commenters. Those commenters included labor organizations, individuals, rail- roads, trade organizations, members of Congress, and state and lo- cal elected officials. 89 Fed. Reg. at 25059 col.1–25075 col.2. More than 98.5 percent of the comments supported the proposed rule. See id. at 25059 col.2. The FRA also held a public hearing on the rule on December 14, 2022. See id. In April 2024, the FRA finalized the Crew Size Rule in an order published in the Federal Register (“Final Rule”). See id. at 25052 col.1. The Crew Size Rule by default requires trains to oper- ate with a minimum of two crewmembers onboard. 49 C.F.R. § 218.123(b). But the Rule has several exemptions.3 It also opens pathways, either by right or upon approval, for covered trains to 3 The Crew Size Rule does not apply to certain tourist and passenger trains, 49 C.F.R. § 218.125, load out, plant dumping, or other similar freight train oper- ations, id. § 218.127, or train operations “controlled by a remote control oper- ator,” id. § 218.121(c). The Rule also has special rules for one-person opera- tions on work trains, helper service trains, and lite locomotive trains; those rules aren’t material to this case. See id. § 218.129(a)(3)–(5). USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 13 of 93 24-11076 Opinion of the Court 13 begin one-person operations. How a railroad moves towards one- person operations varies based on the size of the railroad and whether it hauls hazardous materials. 4 The first, “notice” option is available to smaller, Class II and Class III freight railroads. 5 These railroads may continue “legacy” one-person operations established at least two years before the Crew Size Rule went into effect, including continuing to transport hazardous materials with a one-person crew. Id. § 218.129(a). They simply must provide written notice and information to the FRA and adopt safety-related operating rules covering three topics: accident response, radio or wireless communication, and installa- tion of “alerters” on the train’s controlling locomotive. 6 See id. § 218.129(b)–(c). Class II and Class III railroads without legacy status may also exercise this same “notice” option to use a one-person crew—but 4 The Crew Size Rule considers a train to carry hazardous materials based on the type and amount of potentially dangerous materials it carries, cross-refer- encing definitions in three other regulations. See 49 C.F.R. § 218.123(c). For ease, we simply use the term “hazardous materials.” 5 Class I railroads include the nation’s largest freight railroads. Class II rail- roads are mid-size, “regional” railroads, while the approximately 600 “short line” Class III railroads are the smallest. 6 An alerter is a device installed in the cab of a train’s locomotive that monitors the locomotive engineer’s actions. 49 C.F.R. § 229.5. If the alerter doesn’t detect activity by the engineer over a certain period, it begins “a sequence of audible and visual alarms” and, if the engineer does not respond, it eventually applies a “penalty brake” to stop the train. Id. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 14 of 93 14 Opinion of the Court 24-11076 only if that operation doesn’t transport hazardous materials. See id. § 218.129(a)(2). The second, “special approval” option is the pathway for other railroads to use a one-person crew. So Class I freight rail- roads, and any railroad seeking to start transporting hazardous ma- terials, must obtain the FRA’s approval to use a one-person crew. These railroads must wait for sign-off from the FRA before they may start using a one-person crew. See id. § 218.131(a)(1). The FRA approval process is more involved. Besides every- thing required in the “notice” option, these railroads must submit a detailed risk assessment to the FRA. See id. §§ 218.131(b)(15), 218.133. The agency then publishes the railroad’s petition and ac- cepts public comments for 60 days. Id. § 218.135(b)–(c). The FRA will grant a railroad’s special-approval petition if the agency con- cludes that the railroad’s proposal is “as safe or safer than” using a two-person crew. See id. § 218.135(d)(2). Under the agency’s time- table, it will normally grant or deny a petition within 120 days of receiving it. Id. § 218.135(d)(2). A railroad that receives special ap- proval must also submit annual reports compiling safety and oper- ational data from its one-person crews. Id. § 218.137. The final Crew Size Rule differs somewhat from the rule that the 2022 Notice proposed. Four substantial changes are rele- vant here. The initial proposal categorically prohibited using one- person crews to transport hazardous materials, but the final version permits this practice based on two-year “legacy” status or special approval. See 89 Fed. Reg. at 25082 col.3–25083 col.1. The final USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 15 of 93 24-11076 Opinion of the Court 15 version of the Rule also allows Class II and Class III railroads that aren’t transporting hazardous materials to begin a new one-person operation through the “notice” path, without special approval. Id. at 25073 col.3–25074 col.1. For railroads that need special approval, the FRA changed the standard railroads must meet from “con- sistent with railroad safety” to “as safe or safer” than a two-person crew, explaining that this provided a clearer baseline. Id. at 25056 col.3. Last, the FRA provided an extended, two-year grace period before “legacy” one-person operations would need to comply with the Rule’s alerter requirement. See id. at 25074 col.3–25075 col.2. The Final Rule states the FRA’s expectation that “the na- tional, uniform standard provided in this rule [will] preempt State laws governing crew size.” Id. at 25061 col.3. The Crew Size Rule went into effect on June 10, 2024. D. Petitions for Review Six railroads and two trade groups filed petitions for review of the Final Rule in the U.S. Courts of Appeals for the Fifth, Sev- enth, Eighth, Eleventh, and District of Columbia Circuits. The U.S. Judicial Panel on Multidistrict Litigation randomly selected the Eleventh Circuit as the court in which to consolidate the peti- tions for review, under 28 U.S.C. § 2112(a)(3). Petitioners organized themselves into two groups. The first group (“AAR Petitioners”) consists of five petitioners. The Associ- ation of American Railroads (“AAR”) is a “nonprofit trade associa- tion representing the nation’s major freight railroads, Amtrak, and USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 16 of 93 16 Opinion of the Court 24-11076 some smaller freight railroads and commuter authorities.” The group includes Union Pacific Railroad Company and BNSF Rail- way Company, which are Class I freight railroads. It also includes Florida East Coast Railway LLC and Indiana Rail Road Company, which are Class II freight railroads. The second group (“Short Line Petitioners”) consists of three petitioners. The American Short Line and Regional Railroad Association describes itself as a “non-profit trade association repre- senting the interests of the nation’s Class II (regional) and approxi- mately 600 Class III (short line) railroads.” This group includes Texas & Northern Railway Company and Nebraska Central Rail- road Company, which are short line railroads. Respondents are the FRA, the Administrator of the FRA, and the U.S. Department of Transportation. We granted a motion to intervene as a respondent by the Transportation Division of the International Association of Sheet Metal, Air, Rail and Transportation Workers (“SMART-TD”). SMART-TD is a labor organization representing train employees who are employed by all Class I railroads in the United States and by numerous Class II and Class III railroads. SMART-TD asserts that it “is the largest railroad union in North America.” 7 7 Besides the parties’ submissions, we also received five amicus briefs. The Chamber of Commerce of the United States, the Ohio Chamber of Com- merce, and the National Taxpayers Union Foundation each filed an amicus brief supporting the Railroads. A coalition of sixteen states filed an amicus USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 17 of 93 24-11076 Opinion of the Court 17 II. STANDARD OF REVIEW We have jurisdiction to review the FRA’s final actions under its safety rulemaking authority. See 49 U.S.C. § 20114(c). When we do so, the Administrative Procedure Act (“APA”) requires us to set aside final agency actions that are “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law” or that are “in excess of statutory jurisdiction [or] authority.” 5 U.S.C. § 706(2)(A), (2)(C). In arbitrary-and-capricious review, a “court may not substi- tute its own policy judgment for that of the agency.” FCC v. Prome- theus Radio Project, 592 U.S. 414, 423 (2021). Instead, we simply en- sure that “the agency has acted within a zone of reasonableness and, in particular, has reasonably considered the relevant issues and reasonably explained the decision.” Id. This standard is “exceed- ingly deferential.” City of North Mia. v. Fed. Aviation Admin., 47 F.4th 1257, 1266 (11th Cir. 2022) (quoting Miccosukee Tribe of Indians of Fla. v. United States, 566 F.3d 1257, 1264 (11th Cir. 2009)). In contrast, whether an agency has exceeded its statutory au- thority is a legal question that we decide independently. See Ins. Mktg. Coal. Ltd. v. FCC, 127 F.4th 303, 311 (11th Cir. 2025). III. AAR PETITIONERS’ CHALLENGE brief supporting Respondents; the Academy of Rail Labor Attorneys and the Brotherhood of Locomotive Engineers and Trainmen filed another. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 18 of 93 18 Opinion of the Court 24-11076 AAR Petitioners challenge the Crew Size Rule on five grounds. First, AAR Petitioners contend that the FRA exceeded its statutory authority because the Rule is not “necessary” for safety. Second, they argue the FRA arbitrarily finalized the Rule on the existing record because the FRA declined to finalize a two-person crew-size rule in 2019 and ignored commenters urging it to gather more data before regulating. Third, AAR Petitioners assert that the FRA unreasonably failed to consider the “substantial” labor costs of the Rule. Fourth, they posit that the Rule conflicts with the Rail Safety Improvement Act’s “railroad safety risk reduction pro- gram.” Finally, AAR Petitioners urge us to conclude that the FRA exceeded its statutory authority by taking too long to finalize the Rule. We address each argument in turn. A. Statutory Authority AAR Petitioners first argue that the Crew Size Rule falls out- side the FRA’s statutory authority to issue safety rules “as neces- sary.” See 49 U.S.C. § 20103(a). As AAR Petitioners see things, the statute empowers the FRA to regulate if, and only if, its rule is “es- sential”—and therefore “necessary”—to safety. Under this view, having insufficient evidence that a requirement would improve safety would leave the FRA powerless to act. We’re not convinced. Reading the FRA’s rulemaking provi- sion as a whole reveals a run-of-the-mill general rulemaking au- thority. The “as necessary” phrase is a grant of discretion about when to issue safety rules—not a stringent evidentiary bar. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 19 of 93 24-11076 Opinion of the Court 19 Instead, the proper inquiry asks whether the FRA reasonably exercised its broad rulemaking authority. AAR Petitioners for- feited this argument, and the agency satisfied that obligation in any event. 1. The FRA’s Authority to Issue Safety Regulations “As Necessary” AAR Petitioners’ “as necessary” argument fundamentally misunderstands the FRA’s rulemaking authority. We explain how that works and why the phrase “as necessary” doesn’t set an evi- dentiary standard. a. The Crew Size Rule falls within the FRA’s general rulemaking power. When assessing the scope of an agency’s statutory authority, we look first to the statute’s text. See Oceanair of Fla., Inc. v. U.S. Dep’t of Transp., 876 F.2d 1560, 1565 (11th Cir. 1989) (“An adminis- trative agency . . . is a creature of Congress and has no authority beyond that granted by Congress.”). Here, the FRA promulgated the Crew Size Rule under the Secretary of Transportation’s general safety rulemaking authority. See 89 Fed. Reg. at 25058 col.2 n.33 (invoking 49 U.S.C. § 20103(a) as its legal authority). That statute says, “The Secretary of Transportation, as necessary, shall pre- scribe regulations and issue orders for every area of railroad safety USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 20 of 93 20 Opinion of the Court 24-11076 supplementing laws and regulations in effect on October 16, 1970.” 49 U.S.C. § 20103(a). 8 This type of general rulemaking authority is common. A recent analysis found that more than 10,000 sections of the Code of Federal Regulations contain regulations that agencies issued under these sorts of general rulemaking powers. See Tamar Katz et al., General Rulemaking Grants and the Federal Trade Commission, 125 COLUM. L. REV. 2215, 2255 (2025). General rulemaking provisions are typically broadly worded. Almost unavoidably, though, they contain some lan- guage discussing a nexus between the rules they authorize and the statutory framework the agency implements. Often, Congress uses the word “necessary” to describe that connection. Lesko v. United States, 161 F.4th 1352, 1362 & n.11 (Fed. Cir. 2025) (en banc) (listing five statutes showing “Congress regularly delegates author- ity to agencies to prescribe regulations ‘necessary’ to implement a statutory scheme”); see also, e.g., 38 U.S.C. § 501(a) (“The Secretary [of the Department of Veterans Affairs] has authority to prescribe all rules and regulations which are necessary or appropriate to carry out the laws administered by the Department . . . .”); 42 U.S.C. § 7601(a) (“The Administrator [of the Environmental Pro- tection Agency] is authorized to prescribe such regulations as are necessary to carry out his functions under this chapter.”). 8 Once again, the Secretary of Transportation delegated this rulemaking power to the Federal Railroad Administrator. See 49 C.F.R. § 1.89(a). USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 21 of 93 24-11076 Opinion of the Court 21 Our precedent explains how we view the phrase “as neces- sary” in an agency’s general rulemaking-authority grant. We’ve said that “[w]hen the ‘empowering provision’ of a statute directs the agency to regulate as necessary to carry out what Congress in- tends, ‘the validity of a regulation promulgated thereunder will be sustained so long as it is reasonably related to the purposes of the enabling legislation.’” United States v. Florida, 938 F.3d 1221, 1230 (11th Cir. 2019) (quoting Mourning v. Family Publ’ns Serv., Inc., 411 U.S. 356, 369 (1973)); accord U.S. Pipe & Foundry Co. v. Webb, 595 F.2d 264, 272–73 (5th Cir. 1979). 9 AAR Petitioners don’t claim that the Crew Size Rule falls short of this standard. Rather, they wish the standard away. But neither of the ways they contend the standard is “doubly wrong” holds water. First, they suggest that we ignore the Mourning standard be- cause Congress used the word “necessary” instead of “related to.” But that’s also true of the cases making up this line of precedent. See, e.g., Webb, 595 F.2d at 273 (“necessary”); Mourning, 411 U.S. at 361–2 (“necessary or proper”); Thorpe v. Hous. Auth. of City of Durham, 393 U.S. 268, 277 (1969) (“necessary”). So that word choice can’t distinguish these precedents. 9 In Bonner v. City of Prichard, 661 F.2d 1206, 1207 (11th Cir. 1981) (en banc), we adopted as our own precedent the decisions that the U.S. Court of Appeals for the Fifth Circuit handed down before October 1, 1981. USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 22 of 93 22 Opinion of the Court 24-11076 AAR Petitioners’ second swing misses, too. They argue that precedents about broad authorities to “effectuate the aim of the Act” are inapt because the FRA’s authority addresses a “single pur- pose” of furthering railroad safety. We don’t see why this distinc- tion matters. But in any case, it makes no difference here. Con- gress enacted the FRA’s rulemaking authority as part of the Federal Railroad Safety Act of 1970. Pub. L. No. 91-458, § 202(a), 84 Stat. 971, 971 (1970) (codified, as amended, at 49 U.S.C. § 20103(a)). So effectuating the aim of the Act is the same as advancing the Act’s single purpose: “to promote safety in all areas of railroad opera- tions.” Id. § 101, 84 Stat. at 971. And when we apply the proper standard—whether the reg- ulation is reasonably related to the purposes of the enabling legis- lation—the Crew Size Rule fits comfortably within the FRA’s au- thority to issue safety rules. In its Final Rule, the FRA gave several explanations why it concluded that the Crew Size Rule promotes safety. First, removing the second crewmember’s ability to apply hand brakes or troubleshoot problems would remove an important check against “human factor caused accidents.” Second, it ensures that all railroads “incorporate safety risk information before imple- menting one-person operations, thereby reducing the risk of need- ing to take corrective action retroactively.” Third, the FRA cred- ited commenters who “provided first-hand accounts of close calls and lives saved by the action of two crewmembers working as a team” and emphasized that a single crewmember’s fatigue or med- ical problems pose a greater safety risk when no redundancy exists USCA11 Case: 24-11076 Document: 97-1 Date Filed: 08/11/2026 Page: 23 of 93 24-11076 Opinion of the Court 23 on board. In the face of these explanations, we cannot say that the agency’s Crew Size Rule is not even “rationally related” to safety. b. “As necessary” confers discretion. Even if we don’t consider the Mourning line of precedent, AAR Petitioners’ argument fails as a simple matter of statutory in- terpretation. We must read the words of a statute in their context. See Republic of Sudan v. Harrison, 587 U.S. 1, 11 (2019). And when doing so, we favor giving statutory text its “most natural reading.” Id. Here, the parenthetical phrase “as necessary” plays a clear role in the sentence, “The Secretary of Transportation, as necessary, shall prescribe regulations and issue orders for every area of railroad safety supplementing laws and regulations in effect on October 16,