## Facts

- Pierce County sought federal hazard-elimination funding under 23 U.S.C. § 152 to improve a particular intersection; an initial request was denied, and a later request was approved after a fatal accident.
- Following the accident, the decedent’s survivors sought county records about accidents and hazards at the intersection.
- Pierce County refused disclosure, asserting the federal privilege in 23 U.S.C. § 409 for materials “compiled or collected” for specified federal highway safety programs.
- The survivors filed (1) a state public-disclosure action seeking documents and (2) a negligence action alleging failure to install adequate traffic controls and seeking related discovery.
- State trial courts ordered disclosure and compelled discovery; the state intermediate appellate court largely affirmed.
- The Washington Supreme Court construed § 409 to turn on whether documents were collected for § 152 purposes, held § 409 unconstitutional under the Commerce Clause and federalism principles, and permitted disclosure under state law.
- Pierce County sought review; the United States intervened to defend the statute.

## Issues

1. Whether 23 U.S.C. § 409, as amended to protect materials “compiled or collected” for federal highway safety programs, is a valid exercise of Congress’s Commerce Clause power and consistent with federalism constraints.
2. Whether § 409 protects only materials generated specifically for § 152 purposes, or also materials originally created for other purposes but later compiled or collected for use in the covered federal programs.

## Decision

- The Supreme Court unanimously held that § 409, including the “compiled or collected” language, is constitutional as an exercise of Congress’s Commerce Clause power.
- The Court held that § 409 applies to materials compiled or collected for the covered federal highway safety programs even if the materials were originally created for other purposes.
- The Court rejected the view that § 409 improperly intrudes on state sovereignty, reasoning that it operates as a federal evidentiary and discovery rule applicable in state and federal courts when Congress legislates within enumerated powers.
- The Court reversed the state supreme court’s constitutional ruling and remanded for determinations of which requested documents fall within § 409 as properly construed.

## Legal Principles

- Congress may regulate to improve safety on highways as channels and instrumentalities of interstate commerce, and may use evidentiary and discovery protections as means to further that regulation.
- 23 U.S.C. § 409 bars both discovery and admission into evidence of reports, surveys, schedules, lists, and related data that are compiled or collected for specified federal highway safety programs.
- “Compiled or collected” extends protection to qualifying materials gathered for program purposes regardless of the materials’ original source or initial purpose.
- A federal evidentiary or discovery rule validly enacted under an enumerated power preempts contrary state rules governing admissibility and discovery, without commandeering state regulation.

## Conclusion

The Court upheld § 409 as a constitutional Commerce Clause measure and interpreted it to broadly protect highway-safety materials compiled or collected for covered federal programs, while remanding to decide which particular documents in the state proceedings were within the statute’s protection.


Pierce County v. Guillen, 537 U.S. 129 (2003)