FMSCA Regulation 325.7

 

§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
If the distance between the microphone location point and the microphone target point is— Highway operations 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 35mi/h
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.
31 ft (9.5 m) or more but less than 35 ft (10.7 m) 87 91 89 93 89 91
35 ft (10.7 m) or more but less than 39 ft (11.9 m) 86 90 88 92 88 90
39 ft (11.9 m) or more but less than 43 ft (13.1 m) 85 89 87 91 87 89
43 ft (13.1 m) or more but less than 48 ft (14.6 m) 84 88 86 90 86 88
48 ft (14.6 m) or more but less than 58 ft (17.1 m) 83 87 85 89 85 87
58 ft (17.1 m) or more but less than 70 ft (21.3 m) 82 86 84 88 84 86
70 ft (21.3 m) or more but less than 83 ft (25.3 m) 81 85 83 87 83 85

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