17 F.4th 1198
D.C. Cir.2021Background
- In 2016 EPA and NHTSA jointly promulgated the "Phase 2" rule setting greenhouse‑gas and fuel‑efficiency standards that, for the first time, applied to certain heavy‑duty trailers (box vans and specified non‑box trailers).
- Truck Trailer Manufacturers Association (the petitioner) challenged the trailer provisions; the D.C. Circuit previously stayed EPA and later NHTSA compliance dates and granted review.
- EPA relied on the Clean Air Act §202 authority to regulate "motor vehicles" and argued trailers are covered as vehicles or as motor‑vehicle components / manufacturer obligations.
- NHTSA relied on the Ten‑in‑Ten provisions of the Energy Independence and Security Act (49 U.S.C. §32902) to regulate "commercial medium‑ and heavy‑duty on‑highway vehicles," contending "vehicle" could include trailers and tractor‑trailer combinations.
- The court majority held that (a) the Clean Air Act’s definition of "motor vehicle" requires a self‑propelled unit, so trailers (which are not self‑propelled) fall outside EPA §202 authority; and (b) in the §32902 context "vehicle" is tied to fuel‑consumption/fuel‑economy metrics and thus does not include motorless trailers, so NHTSA lacked authority to regulate trailers; the court vacated all rule portions applying to trailers.
- Judge Millett concurred in the judgment as to EPA (agreeing trailers are not "self‑propelled") but dissented as to NHTSA, arguing Chevron deference applied and that the statutory text, context, purpose and agency practice reasonably support treating on‑highway trailers (as part of tractor‑trailers) as "vehicles." She also concluded NHTSA rules were severable from EPA’s.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| 1) May EPA regulate trailers under CAA §202 as "motor vehicles"? | Trailers are not self‑propelled and thus not "motor vehicles." | Trailers function as part of the tractor‑trailer vehicle and/or are significant vehicle components; trailer manufacturers should be regulated. | No. "Motor vehicle" in §202 requires a self‑propelled vehicle; trailers are excluded. |
| 2) May EPA treat trailer makers as motor‑vehicle manufacturers under CAA definitions? | Trailer makers are not "manufacturers" of self‑propelled motor vehicles and cannot meet statutory obligations tied to whole vehicles. | Multiple manufacturers can contribute to one vehicle; trailer makers participate in producing the vehicle. | No. Trailer manufacturers are not within §7550(1) manufacturer definition for §202 regulation. |
| 3) May NHTSA regulate trailers under §32902 as "commercial medium‑/heavy‑duty on‑highway vehicles"? | "Vehicle" in §32902 is tied to fuel‑economy (miles/gallon); trailers use no fuel and therefore are not "vehicles" in that context. | The term "vehicle" is ambiguous; Chevron deference permits NHTSA to include on‑highway trailers (tractor‑trailers) given statutory purpose and precedent definitions. | No. In §32902’s context, "vehicle" is limited to machines with fuel economy; trailers are excluded and NHTSA lacked authority. |
| 4) If EPA trailer provisions are vacated, must NHTSA’s trailer rules also fall (severability)? | The two agencies’ rules are interlinked and overlap; vacating EPA’s provisions undermines NHTSA’s. | The agencies intended the standards to be legally severable; NHTSA’s rules can function independently. | Court vacated all portions applying to trailers. (Judge Millett would have upheld NHTSA and treated the rules as severable.) |
Key Cases Cited
- Chevron U.S.A., Inc. v. Natural Res. Def. Council, Inc., 467 U.S. 837 (establishes two‑step framework for reviewing agency statutory interpretation)
- Mead Corp. v. United States, 533 U.S. 218 (legislative rules and circumstances for Chevron deference)
- FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120 (canons for reading statutory terms in context and statutory silence implications)
- City of Arlington v. FCC, 569 U.S. 290 (agency interpretation of statutory ambiguity may be upheld)
- Yates v. United States, 574 U.S. 528 (noscitur a sociis and interpreting a word by its context)
- Free Enterprise Fund v. Public Co. Accounting Oversight Bd., 561 U.S. 477 (severability principles in reviewing agency actions)
- Delta Constr. Co. v. EPA, 783 F.3d 1291 (D.C. Cir.) (noting equivalence of tailpipe GHG limits and fuel‑consumption limits)
- Global Tel*Link v. FCC, 866 F.3d 397 (D.C. Cir.) (agency abandonment of positions and its effect on deference)
- Verizon v. FCC, 740 F.3d 623 (D.C. Cir.) (severability analysis for agency orders)