EXHIBIT 4-2_55A_BRISTOL WIDENING TECHNICAL STUDIES

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time hours (7 AM to S PM, excluding federal holidays) when noise intrusion is less disruptive. The local noise ordinance speci- fies which hours each day construction activities can occur. Federal Standards: The "Federal Highway Program Manual" (FHPM 7- 7-3 ) requires that sand use activities which may be affected by highway construction noise be identified. In addition, the mea- sures needed in the plans and specifications to minimize or eliminate construction noise impacts must be determined. Howe- ver, no specific guidelines are available for assessing the significance of construction noise impacts. The 1981 California Standard Specifications (Section 7- 1.0113, Section 42 -1.02, and Section 42 -2.02 (shown on page 17 of the Appendix) and Standard Caltrans Special Provisions Section 5 -1 (Sound Control Requirements) may be referenced in project plans and specifications when they apply to minimize or eliminate construction noise impacts. A diagram illustrating various con- struction noise control strategies developed by Caltrans is in- cluded on page 18 of the Appendix. Long --Term Acoustic Impacts Daily traffic data for future conditions with and without the project was provided by Willdan Associates. The findings of the traffic study indicate that daily traffic volumes would not change with the proposed project versus the no- project alterna- tive. However, traffic congestion along Bristol Street would de- crease, and a consistent set of improvement standards would also improve safety and other operational characteristics. Future noise levels within the APEI were projected by employing the FHWA RD -77 -108 Highway Traffic Noise Prediction Model. Noise contours were developed as a planning tool for local agencies. Boise emission levels were obtained from National Reference Ener- gy Mean Emission Levels as a Function of Speed (per paragraph 14 of FHPM 7 -7 -3). The posted speed limit was assumed to be repre- sentative of future mid -block conditions with the proposed pro- ject and the no- project scenarios as a "worst case" assumption. A 2.58 percent truck a mix was assumed along Bristol Street as shown on page 15 of the Appendix. Cif Standards: Table 4-7 shows the community noise equivalent levels which can be expected adjacent to each roadway link within the APEI for design year (2006) conditions with the proposed project and the no- project alternative. As shown, future noise levels adjacent to Bristol Street will be higher with the pro- posed project than with the "no- build" alternative because of the wider pavement width. The increase would amount to I dSA or less. The unattenuated 70 CNEL contour will fall between 66 and 130 F. feet from the centerline of Bristol Street in the design year 4-14