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analysis results are consistent with those of the MHMP Elft in terms of segment LOS operations.The freeway segments are forecast to operate at LOS F,representing a significant and unavoidable impact,with or without the project. _ As explained earlier,these volumes are based on unconstrained assignments,although and likely upstream constraints would preclude these volumes from reaching the study area.Once the freeway is saturated and operating at LOS F,additional traffic could not be realized in the same peak hour. As commute traffic on highway facilities reaches congested levels, commuters begin to change their travel patterns by either finding less-congested routes or commuting during off-peak hours.The latter response, known _ as peak spreading,is already occurring on I-580 and I-205. It is becoming especially pronounced in this area for which no direct corridorwide,uncongested reasonable alternative routes exist. In the past,the a.m.peak period generally occurred between 7:00 to sometime after 9:00.Now the peak period starts close to 5:00 a.m.and extends well past 10:00 a.m. In the p.m.peak period,peak spreading starts around 3:00 p.m. and lasts until 7:00 or 8:00 p.m. instead of the traditional 4:00 to 6:00 p.m. For example,with four lanes in each direction of I-580 at the Altamont Pass,the maximum theoretical capacity is approximately 8,800 vehicles per hour.The MHMP EIR forecasted a demand of approximately 10,440 vehicles per hour at the same location.The theoretical capacity of 8,800 vehicles per hour on I-580 would not be able to _ accommodate even this projected MHMP EIR demand.In this situation,peak spreading would occur. The current model projects a regional traffic demand of approximately 21,000 vehicles per hour in 2025.The freeway would not be able to accommodate all the projected demand in one peak hour.The projected traffic could be realized only through peak spreading. As noted previously,the current 2025 regional traffic projections are much higher than the MHMP EIR traffic projections because the current SJCOG model includes many regional developments that were not previously included in the SJCOG model.In addition,the current model is more comprehensive and accurate. It appears that past model forecasting has underestimated the regional traffic demand. _ The traffic from the MHMP area is projected in the current analysis to remain essentially the same as that evaluated in the MHMP EIR. Therefore,the projected traffic impacts would remain relatively unchanged from those identified in the MHMP EIR. Impacts on local segments of I-580 and 1-205, and on I-5 north of I-205, would be significant and unavoidable as previously identified in the MHMP EIR. Analysis of Previously Adopted Mitigation for Link-Level Impacts Table 4.11-15 highlights arterial roadway segments with significant impacts identified in the MHMP EIR or the current 2025 analysis.Table 4.11-15 also shows the LOS before and after implementation of the mitigation measures recommended for the roadway segments in the MHMP EIR and approvals associated with Neighborhoods E,F,and G. In both cases, roadway widening is needed to maintain acceptable LOS. The LOS after mitigation is D or better for most arterial segments with or without the I-205/Lammers Interchange. At all but one link location(Altamont Pass Road west of Grant Line Road),the MHMP EIR mitigation measures are expected to reduce project impacts to less-than-significant levels(see last column of Table 4.11-15). Under the current 2025 analysis,LOS would be at a less-than-significant level with implementation of the mitigation measures identified in the MHMP EIR for several roadway segments, including the following(see shading in Table 4.11-15): • Mountain House Parkway south of I-205 • Mountain House Parkway north of I-205 • Mountain House Parkway north of Grant Line Road — • Middle/Arbor Avenue east of Tracy Boulevard EDAW College Park at Mountain House Specific Plan III Draft EIR — Transportation 4.11-38 San Joaquin County