Traffic noise mitigation may also occur using physical methods that mask
or minimize unwanted sounds. These methods include:
- acoustical site planning,
- acoustical architectural design,
- acoustical construction, and
- construction of noise barriers.
Although neither the FHWA nor the LaDOTD specifically require any of the
above strategies for noise mitigation, they do require that if noise impacts
are expected, that noise-reduction be practicable, reasonable, and acceptable
to the public within the community where they are incorporated. Therefore,
the strategies that are suggested here (excluding noise barriers) would likely
be accomplished through a local agency. Acoustical site planning uses arrangement
of buildings on a tract of land to minimize noise impacts. This may be accomplished
by:
- placing distance between the noise source and noise sensitive activities,
- placing
noise-compatible activities such as parking lots, open space and commercial
facilities between the noise source and sensitive activities,
- using
buildings as barriers, and
- orienting noise-sensitive buildings
to face away from the noise source.
In each of the above cases the I-49 Connector is the source of noise to
minimize. A strategy proposed by the Workshop recommends placing three-story
buildings adjacent to the proposed highway to act as a sound barrier for the
surrounding residential neighborhoods. In moving away from the I-49 Connector
into the neighborhoods, there would be a layering of these three-story buildings
followed by parking lots, open space, and low-rise commercial development
that would place distance between the proposed highway and the surrounding
residents.
Acoustical architectural design incorporates noise-reducing concepts in the details
of the individual buildings. These details might include:
- building height,
- room arrangement,
- window size, number, and
placement, and
- balcony and courtyard design.
A specific example that illustrates
the way these details might be incorporated into a building would be the
previously mentioned three-story buildings adjacent to the proposed highway.
Three-story
buildings act like a wall and prevent some of the most severe traffic noise
from intruding on the surrounding residential area. Within these three-story
buildings, noise-compatible activities (storage, laundry, and restrooms)
could be placed on the side adjacent to the I-49 Connector, while rooms with
noise-sensitive
activities (social) could be placed opposite the connector. Reduction in
the number of windows and window area would minimize sound transmission of
traffic
noise into the spaces. Placement of balconies and courtyards on the side
of the building opposite the I-49 Connector would add distance to the path
of
travel of the traffic noise. This distance would also provide spaces for
outdoor activities that use the structures to block traffic noise.
Along with acoustical architectural design, acoustical construction comes
into play. Acoustical construction comes into play. Acoustical construction
is the treatment of various parts of a building to reduce interior noise
impacts by increasing the building mass, increasing the rigidity of materials
used in construction, and providing air spaces in walls, floors and ceilings.
These methods fall within the concept of "soundproofing." The "soundproofing" of
public-use institutional buildings may be incorporated into federally-aided
highway projects to abate traffic noise, but the use of federal funds for
soundproofing commercial buildings of private dwellings is not normally
permitted. |
