EXHIBIT 4-2_55A_BRISTOL WIDENING TECHNICAL STUDIES

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GENERAL METHODS TO REDUCE NOISE IMPACTS Acoustic site planning involves the careful arrangement of land uses, lots and buildings to minimize intrusive noise levels. The placement of noise compatible land uses between the roadway and more sensitive uses is an effective planning technique. The use of buildings as noise barriers, and their orientation away from the source of noise, can shield sensitive activities, entrances and common open space areas. Clustered and planned unit devel- opments can maximize the amount of open space available for landscaped buffers next to heavily travelled roadways and thereby allow aesthetic building setbacks in place of continuous noise barriers. Acoustic architectural design involves the incorporation of noise reducing strategies in the design and lay -out of individual structures. Building heights, room arrangements, window size and placement, balcony and courtyard design, and the provision of air conditioning all play an important role in shielding noise sensi- tive activities from intrusive noise levels. Acoustic construction is the treatment of various parts of a building to reduce interior noise levels. Acoustic wall design, doors, ceilings and floors, as well as dense building materials, the use of acoustic windows (double glazed, double paned, thick, non-- openable, or small with air -tight seals) and the inclusion of maximum air spaces in wails are all available options. Ideally, noise barriers incorporate the placement of berms, wails or a combination of the two in conjunction with appropriate landscaping to effect an aesthetically pleasing environment. Where space is available (clustered developments) a meandering earth berm is both effective and pleasing. Where space is re- stricted, a wall is effective. In either case, however, thick landscaping (without deciduous plants) should be specified to reduce the visual impact of the barrier and retain the rural ambiance. 16