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FHWA noise table

 

 

TABLE 1
FHWA NOISE ABATEMENT CRITERIA1 (NAC), HOURLY A-WEIGHTED SOUND LEVEL IN DECIBELS (dBA)

Activity Category
Leq (h)
L10(h) 2
Description of Activity Category
A
57 (exterior)
60 (exterior)
Lands where serenity and quiet are of extraordinary significance and serve an important public need and where the preservation of those qualities is essential if the area is to continue to serve its intended purpose.
B
67 (exterior)
70 (exterior)
Picnic area, recreation area, playgrounds, active sports, parks, residences, motels, hotels, schools, churches, libraries, and hospitals.
C
72 (exterior)
75 (exterior)
Developed lands, properties, or activities not included in Categories A or B above.
D
--
--
Undeveloped lands.
E
52 (interior)
55 (interior)
Residences, motels, hotels, public meeting rooms, schools, churches, libraries, hospitals, and auditoriums.

1Federal-Aid Highway Program Manual; Vol. 7, Ch. 7, Sec. 3, Attachment, Transmittal 348, 8/9/82.
2 Either L10(h) or Leq(h) (but not both) may be used on a project. This report uses the L10(h) per MPCA standards.

 

 

 

TABLE 2
NOISE LEVEL STANDARDS OF THE MPCA1

Category
General Land Use Types
Daytime Noise Levels
(7 A.M. to 10 P.M.)
Nighttime Noise Levels
(10 P.M. to 7 A.M.)
NAC-1
Residential & Institutional
L10 of 65 dBA
L50 of 60 dBA
L10 of 55 dBA
L50 of 50 dBA
NAC-2
Commercial & Recreational
L10 of 70 dBA
L50 of 65 dBA
L10 of 70 dBA
L50 of 65 dBA
NAC-3
Industrial
L10 of 80 dBA
L50 of 75 dBA
L10 of 80 dBA
L50 of 75 dBA
1 Minnesota Statutes Chapter 7010--Noise Pollution Control--Subp.