49 C.F.R. § 325.7

Current through September 30, 2024
Section 325.7 - Allowable noise levels

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

Highway operation testStationary tests
Soft siteHard SiteSoft siteHard site
35 mi/h or less Above 35 mi/h35 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)879189938991
35 ft (10.7m) or more but less than 39 ft (11.9m)869088928890
39 ft (11.9m) or more but less than 43 ft (13.1m)858987918789
43 ft (13.1m) or more but less than 48 ft (14.6m)848886908688
48 ft (14.6m) or more but less than 58 ft (17.1m)838785898587
58 ft (17.1m) or more but less than 70 ft (21.3m)828684888486
70 ft (21.3m) or more but less than 83 ft (25.3m)818583878385

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 .

49 C.F.R. §325.7

40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989