49 CFR § 325.7
Allowable noise levels
November 18, 2020
Motor vehicle noise emissions, when measured according to the rules of this part, shall not exceed the values specified in Table 1.
Table 1—Maximum Permissible Sound Level Readings (Decibel (A))1 2
Open Table
| 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 |
1The speeds shown refer to measurements taken at sites having speed limits as indicated. These speed limits do not necessarily have to be posted.
2This 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]
Tried the LawStack mobile app?
Join thousands and try LawStack mobile for FREE today.
- Carry the law offline, wherever you go.
- Download CFR, USC, rules, and state law to your mobile device.
