Table 5.9-2 Increase in Cumulative Noise Allowed by FTA Criteria
|
Existing Noise Exposure Leq or Ldn 1 |
Allowable Cumulative Noise Level Increases Leq or Ldn 1 |
|||
|
Category 1 or 2 Sites |
Category 3 Sites |
|||
|
Impact |
Severe Impact |
Impact |
Severe Impact |
|
|
45 |
8 |
14 |
12 |
19 |
|
46 |
7 |
13 |
12 |
18 |
|
47 |
7 |
12 |
11 |
17 |
|
48 |
6 |
12 |
10 |
16 |
|
49 |
6 |
11 |
10 |
16 |
|
50 |
5 |
10 |
9 |
15 |
|
51 |
5 |
10 |
8 |
14 |
|
52 |
4 |
9 |
8 |
14 |
|
53 |
4 |
8 |
7 |
13 |
|
54 |
3 |
8 |
7 |
12 |
|
55 |
3 |
7 |
6 |
12 |
|
56 |
3 |
7 |
6 |
11 |
|
57 |
3 |
6 |
6 |
10 |
|
58 |
2 |
6 |
5 |
10 |
|
59 |
2 |
5 |
5 |
9 |
|
60 |
2 |
5 |
5 |
9 |
|
61 |
1.9 |
5 |
4 |
9 |
|
62 |
1.7 |
4 |
4 |
8 |
|
63 |
1.6 |
4 |
4 |
8 |
|
64 |
1.5 |
4 |
4 |
8 |
|
65 |
1.4 |
4 |
3 |
7 |
|
66 |
1.3 |
4 |
3 |
7 |
|
67 |
1.2 |
3 |
3 |
7 |
|
68 |
1.1 |
3 |
3 |
6 |
|
69 |
1.1 |
3 |
3 |
6 |
|
70 |
1.0 |
3 |
3 |
6 |
|
71 |
1.0 |
3 |
3 |
6 |
|
72 |
0.8 |
3 |
2 |
6 |
|
73 |
0.6 |
2 |
1.8 |
5 |
|
74 |
0.5 |
2 |
1.5 |
5 |
|
75 |
0.4 |
2 |
1.2 |
5 |
Category 1: Buildings or parks where quiet is an essential element of their purpose
Category 2: Residences and buildings where people normally sleep. This includes residences, hospitals,
and hotels where nighttime sensitivity is assumed to be of utmost importance
Category 3: Institutional land uses with primarily daytime and evening use. This category includes schools,
libraries, and churches
1
Ldn is used for land uses where nighttime sensitivity is a factor; Daytime Leq is used for land uses with onlydaytime activities
Source: FTA Manual for Transit Noise and Vibration Impact Assessment, FTA April 1995