Rulebook › 49 CFR Part 325
PART 325—COMPLIANCE WITH INTERSTATE MOTOR CARRIER NOISE EMISSION STANDARDS
Official text from the eCFR, current as of 2026-10-22. View this part on eCFR.gov
Subpart A—General Provisions
- § 325.1 Scope of the rules in this part.
- § 325.3 [Reserved]
- § 325.5 Definitions.
- § 325.7 Allowable noise levels.
- § 325.9 Measurement tolerances.
Subpart B—Administrative Provisions
- § 325.11 Issuance, amendment, and revocation of the rules in this part.
- § 325.13 Inspection and examination of motor vehicles.
Subpart C—Instrumentation
- § 325.21 Scope of the rules in this subpart.
- § 325.23 Type of measurement systems which may be used.
- § 325.25 Calibration of measurement systems.
- § 325.27 Use of a windscreen.
Subpart D—Measurement of Noise Emissions; Highway Operations
- § 325.31 Scope of the rules in this subpart.
- § 325.33 Site characteristics; highway operations.
- § 325.35 Ambient conditions; highway operations.
- § 325.37 Location and operation of sound level measurement system; highway operations.
- § 325.39 Measurement procedure; highway operations.
Subpart E—Measurement of Noise Emissions; Stationary Test
- § 325.51 Scope of the rules in this subpart.
- § 325.53 Site characteristics; stationary test.
- § 325.55 Ambient conditions; stationary test.
- § 325.57 Location and operation of sound level measurement systems; stationary test.
- § 325.59 Measurement procedure; stationary test.
Subpart F—Correction Factors
- § 325.71 Scope of the rules in this subpart.
- § 325.73 Microphone distance correction factors. 1
- § 325.75 Ground surface correction factors. 1
- § 325.77 Computation of open site requirements—nonstandard sites.
- § 325.79 Application of correction factors.