Current textIn force on Feb. 13, 2026Source: eCFR
§ 325.7 Allowable noise levels.
Current wording, effective January 1, 2017.
49 CFR § 325.7 — Allowable noise levels.. Text in force on February 13, 2026. This wording effective January 1, 2017 to present. Source: eCFR as of February 13, 2026, https://www.ecfr.gov/on/2026-02-13/title-49/section-325.7. Retrieved from FMCSR.com, https://fmcsr.com/reg/325.7?asof=2026-02-13, on October 26, 2026. Unofficial compilation; verify against the official source.
Motor vehicle noise emissions, when measured according to the rules of this part, shall not exceed the values specified in Table 1.
| Highway operation test | Stationary tests | |||||
|---|---|---|---|---|---|---|
| Soft site | Hard Site | Soft site | Hard site | |||
| 35 mi/h or less | Above 35 mi/h | 35 mi/h or less | Above 35 mi/h | |||
| If the distance between the microphone location point and the microphone target point is— | ||||||
| 31 ft (9.5m) or more but less than 35 ft (10.7m) | 87 | 91 | 89 | 93 | 89 | 91 |
| 35 ft (10.7m) or more but less than 39 ft (11.9m) | 86 | 90 | 88 | 92 | 88 | 90 |
| 39 ft (11.9m) or more but less than 43 ft (13.1m) | 85 | 89 | 87 | 91 | 87 | 89 |
| 43 ft (13.1m) or more but less than 48 ft (14.6m) | 84 | 88 | 86 | 90 | 86 | 88 |
| 48 ft (14.6m) or more but less than 58 ft (17.1m) | 83 | 87 | 85 | 89 | 85 | 87 |
| 58 ft (17.1m) or more but less than 70 ft (21.3m) | 82 | 86 | 84 | 88 | 84 | 86 |
| 70 ft (21.3m) or more but less than 83 ft (25.3m) | 81 | 85 | 83 | 87 | 83 | 85 |
| 1 The speeds shown refer to measurements taken at sites having speed limits as indicated. These speed limits do not necessarily have to be posted. | ||||||
| 2 This table is based on motor carrier noise emission requirements specified in 40 CFR 202.20 and 40 CFR 202.21. |
[40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]
Amendment history
4 distinct wordings on file since Oct. 1, 1996- [40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]
- [40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]
- [40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]
- Oct. 1, 1996 → Oct. 1, 2001annual editions 1996–2000[40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]
A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.