EXHIBIT 4-1_55A_BRISTOL WIDENING EIS-EIR

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After the widening of Bristol Street, some of the measurement locations would fall within the right -of -way for some of the project alternatives. Calculations of future noise levels were not included for alternatives where the noise impacted structure is being removed. Since the front edge of the residential dwellings adjacent to measurement site No. 7 are on the right -of -way for alternative 2, there is no room for a noise barrier, and no barrier attenuation calculations were made. Finally, barrier attenuation calculations were not made for "no- mitigation" noise levels at or below 63 Leq. The noise impact from Bristol Street on residential areas falls into several categories. Many dwellings front onto Bristol Street with access directly onto Bristol Street, or with access to an alley in the back. The front yard noise impacts could be mitigated by constructing a barrier at the right -of -way, however pedestrian or pedestrian and vehicular access may be restricted by construction of a contiguous noise barrier. Dwellings with the side yard facing Bristol Street typically have front yard impacts. However, construction of a 6 -foot block wall protecting the front yard may reduce the visibility of motorists approaching Bristol Street and may also have aesthetic impacts. Several dwellings with side yards facing Bristol Street have rear yards enclosed by chain link fencing. The noise impacts on these rear yard activity areas will be similar to front yard impacts, but access conflicts will not be a consideration. Construction of a perimeter 6 -foot block wall at the right -of -way would reduce noise levels to acceptable levels at these units. Several alternatives include taking a portion of school activity fields or playgrounds. For alternatives where the noise measurement location was within the right -of -way, the measurements were adjusted to reflect conditions ten feet behind the future right -of -way. Second line receptors (i.e., receptors impacted when abutting structures are removed) are often of concern adjacent to freeways, but are generally not severely impacted in local roadway widening projects. Measurements at sites 12, 12A, 13, and 13A were made to assess the front and back yard impacts on a typical worst -case second line receptor. A field review of the sensitive noise receptors located adjacent to Bristol Street within the project area indicates exceedances of federal exterior noise criteria for approximately 167 front yard activity areas. Of these dwellings, 68 front onto Bristol Street with direct vehicular access, and 99 have vehicular access to a rear alley or to a side street. In addition, seven of these dwellings have noise impacts in rear yard activity areas (six yards surrounded by chain link and one with no fencing). IV -27