49 CFR § 325.31 - Scope of the rules in this subpart.

---
identifier: "/us/cfr/t49/s325.31"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 325.31 - Scope of the rules in this subpart."
title_number: 49
title_name: "Transportation"
section_number: "325.31"
section_name: "Scope of the rules in this subpart."
chapter_name: "FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "A"
subchapter_name: "GENERAL REGULATIONS"
part_number: "325"
part_name: "COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 4917; 49 U.S.C. 301; and 49 CFR 1.87."
regulatory_source: "40 FR 42437, Sept. 12, 1975, unless otherwise noted."
cfr_part: "325"
---


# 325.31 Scope of the rules in this subpart.

The rules in this subpart specify conditions and procedures for measurement of the sound level generated by a motor vehicle engaged in a highway operation for the purpose of ascertaining whether the motor vehicle conforms to the Standards for Highway Operations set forth in 40 CFR 202.20.