## Facts

- Congress directed the Secretary of Transportation, acting through FHWA, to set national bridge inspection standards, including “the maximum time period between inspections,” for all highway bridges on public roads under 23 U.S.C. § 151.
- FHWA regulations historically set a two-year maximum inspection interval for most bridges and reaffirmed the importance of that interval in 1984.
- In 1988, FHWA amended the national bridge inspection standards to permit certain bridges to be inspected less often than every two years and, for some categories, effectively without any specified maximum interval.
- The 1988 amendments also added a requirement for inspections of underwater bridge substructure elements and set a five-year maximum interval for underwater inspections, relying largely on engineering judgment due to limited data.
- The Center for Auto Safety petitioned FHWA to reconsider, arguing (1) the effective absence of a maximum interval for some bridges violated § 151, and (2) the five-year underwater interval lacked adequate support and conflicted with FHWA’s earlier emphasis on two-year inspections.
- FHWA denied the petition, generally asserting reliance on studies, experience, and risk-based resource allocation without clearly identifying or analyzing the supporting materials in the administrative record.
- The district court upheld the regulations; the Center for Auto Safety appealed.

## Issues

1. Whether FHWA’s 1988 amendments unlawfully violated 23 U.S.C. § 151 by allowing some covered bridges to have no specified “maximum time period between inspections.”
2. Whether FHWA’s selection of a five-year maximum interval for underwater bridge inspections was arbitrary and capricious under the APA for inadequate explanation and record support.

## Decision

- The D.C. Circuit affirmed in part, reversed in part, and remanded.
- The court held § 151 requires FHWA to prescribe an actual maximum inspection interval for all covered highway bridges; FHWA could not create categories with no maximum interval.
- The court recognized FHWA’s discretion to set different maximum intervals for different bridge categories, including longer intervals for lower-risk bridges, so long as a maximum exists.
- The court remanded the underwater-inspection interval because FHWA did not sufficiently explain, on the record, why five years was appropriate given safety concerns, prior agency statements favoring two-year intervals, and significant comments opposing the change.
- The court did not hold that a five-year underwater interval was categorically impermissible, only that FHWA needed a reasoned, record-based explanation if it retained that standard.

## Legal Principles

- When a statute directs an agency to set a “maximum” inspection interval, the agency must establish an enforceable outer limit for all facilities within the statute’s scope; it may not leave subsets without any maximum.
- Under APA arbitrary-and-capricious review, an agency must examine relevant information and provide a reasoned explanation connecting the record to the policy choice, particularly when changing course on safety-related standards.
- Agencies may rely on technical judgment and expertise, but they must explain how that judgment supports the specific rule and must address significant comments raising substantial legal or safety objections.
- Judicial review is confined to the administrative record; post hoc or generalized assertions of support are insufficient if the record does not reveal the agency’s reasoning at the time of decision.

## Conclusion

The court required FHWA to comply with § 151 by setting a maximum inspection interval for all covered bridges and remanded the underwater-inspection standard for further explanation because the agency’s stated rationale did not adequately justify the five-year interval on the administrative record.


Ctr. for Auto Safety, Inc. v. Fed. Highway Admin., 956 F.2d 309 (D.C. Cir. 1992)