49 CFR § 325.71 - Scope of the rules in this subpart.
---
identifier: "/us/cfr/t49/s325.71"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 325.71 - Scope of the rules in this subpart."
title_number: 49
title_name: "Transportation"
section_number: "325.71"
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"
---
# 325.71 Scope of the rules in this subpart.
(a) The rules in this subpart specify correction factors which are added to, or subtracted from, the reading of the sound level generated by a motor vehicle, as displayed on a sound level measurement system, during the measurement of the motor vehicle's sound level emissions at a test site which is not a standard site.
(b) The purpose of adding or subtracting a correction factor is to equate the sound level reading actually generated by the motor vehicle to the sound level reading it would have generated if the measurement had been made at a standard test site.