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The College Park project includes proposals for sound walls along portions of Grant Line Road and DeAnza Boulevard as shown in Figure 3-10 in Chapter 3,"Project Description,"but does not propose noise walls along all roadway segments analyzed.Table 4.3-11 identifies the roadway segments where sound walls are and are not proposed.Also,although sound walls are proposed along some roadway segments requiring sound walls,the exact height of the sound walls is not specified in the College Park at Mountain House Specific Plan III.Therefore,a significant impact would occur. Traffic Noise—Interstate 205 Predicted traffic noise levels from I-205 traffic for future buildout conditions in the year 2025 are presented in Table 4.13-12.These predicted traffic noise levels were calculated using the FHWA Traffic Noise Prediction _ Model.Input data used in the model included average daily traffic levels for nearby roads,day/night percentages of autos and medium and heavy trucks,vehicle speeds,ground attenuation factors,and road widths.Input information was based on the traffic analyses prepared for the project(see Section 4.11 "Transportation")(TJKM 2004). As indicated in Table 4.13-2,the 75, 70, 65,and 60-dBA CNEL noise contours from I-205 in year 2025 would extend into the College Park project site by 290,633, 1,361, and 2,931 feet,respectively.The resultant noise contours are shown graphically in Figure 4.13-2. As indicated in the proposed Concept Plan and Landscape Framework (Figures 3-613 and 3-9 in Chapter 3), an approximately 100-foot landscaped buffer is proposed on the College Park project site adjacent to the north side of I-205,followed by 32.3 acres of proposed limited industrial uses and a portion of the proposed community college.North of the proposed limited industrial uses is the proposed Central Parkway followed by residential uses, starting approximately 600 feet north of the freeway.Approximately 1,150 north of the freeway is the southern boundary of the proposed community park.Based on this information,the following proposed uses would be subject to noise levels from I-205 above the applicable thresholds of 65 dBA CNEL for residential and community park uses, 70 dBA CNEL for college uses, and 75 dBA CNEL for limited industrial uses: ► Community College.The southern 191 feet of the community college would be subject to freeway noise of up to 75 dBA CNEL;portions of the college between 192 and 633 feet would be subject to freeway noise of up to 70 dBA CNEL. ► Residences.The first row of residences along the north side of Central Park would be subject to freeway noise of up to 65 dBA CNEL; residences between this first row of residences and those up to 2,931 feet from the freeway would be subject to freeway noise of up to 60 dBA CNEL. Table 4.13-12 Predicted 1-205 Traffic Noise Levels with College Park Buildout In 2025 Noise Level(dBA CNEL) Major Road Segments 50 Feet from Distance of CNEL Contour(feet) Roadway Centerline 60dBA 65dBA 70dBA 75 dBA r,. I-205 between Interstate 580 Split and Mountain House Parkway Interchange 83.36 2,931 1,361 633 290 Notes: Based on 2025 cumulative traffic conditions(year 2025 base case plus full buildout of the College Park project).Traffic noise levels were modeled using the FHWA Traffic Noise Prediction Model,based on traffic information(e.g.,average daily traffic,vehicle speeds,road width)obtained from the analysis prepared for this project CfJKM 2004).As a result,the noise contour distances should be considered as representative bands of similar noise exposure,rather than absolute distances of demarcation.Actual noise levels would vary from day to .. day,depending on a number of factors,including local traffic volumes,shielding from existing structures,variations in attenuation rates resulting from changes in surface parameters,and meteorological conditions.Refer to the noise modeling input/output available at SJCCDD for more detailed input assumptions and modeling output results. Source:Data compiled by EDAW in 2004 College Park at Mountain House Specific Plan III Draft EIR EDAW San Joaquin County 4.13-27 Noise