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widening in these model runs; the mitigations are at the intersection level only.) Mitigation measures significantly reduce overall delay (about 60 percent in the P.M. and 55 percent in the A.M.) in Year 2010 compared to unmitigated Year 2010 conditions. Even with additional mitigations, with Year 2025 regional traffic growth, delay increases by another five percent in the P.M. over mitigated Year 2010 conditions. During the morning peak hour, however, traffic delay is reduced by 13 percent relative to mitigated 2010 conditions by the proposed Year 2025 mitigations and the regional 2025 roadway network. With intersection mitigations alone, a small number of intersections continue to function at a level of service worse than level-of-service D, the current General Plan standard, in the Year 2025 model run. Most of these are within the Downtown, currently exempt from this standard. The key unmitigated intersections not in the Downtown are Hopyard Road at the 1-580 off-ramp and at Owens Drive, and Sunol Boulevard at Sycamore Road. CONSTRAINED GATEWAY CONCEPT One important assumption in the Year 2025 model run which is key to future runs is the effect that congestion at major city gateways has on overall city traffic. Most gateways are fairly congested in the Year 2025 model run. This congestion impacts local drivers and limits cut-through traffic to a degree. For future traffic modeling purposes, staff intends to explore alternatives which continue to limit cut-through traffic by street design, while minimizing congestion along City streets not heavily used by through traffic. This will allow reasonable comparisons to be made and to better reflect the City's sensitivity to other traffic-related effects such as livability, noise, etc. As has been previously described, all the model runs to date have been "constrained" model runs rather than "demand" model runs. A constrained model run takes into account congestion on all routes if traffic volumes generated by the assumed land uses approach or exceed the traffic-carrying capacity of the assumed traffic network. A demand model run, on the other hand, simply places traffic where the land use/traffic assumptions would put it on a give traffic network as if adequate capacity exists everywhere. A demand model run, in essence, would show how traffic would move on an overall network if there were no congestion. However, since congestion appears to be a long-term fact of life on most regional routes which are key to Pleasanton's planning, constrained model runs have been used. These replicate actual travel behavior described earlier: peak-hour spreading and cut-through traffic. SR 05:135 Page 5