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1 a W AL 'I operational rates, vehicle trip lengths, and level of service on adjoining roadways would be similar for all three of these alternatives. As previously indicated in Table 4.5-8, operation of the proposed project would result in + ' increased emissions of CO generated by mobile sources. As discussed in Section 4.4, the Koster Road/State Route (SR) 132 intersection and the Interstate 5 (1-5)Isouth-bound on- 0 ramp at Bird Road are projected to operate at unacceptable levels of service during AM peak hours under cumulative conditions. As a result, localized CO concentration may occur at these inter-sections, which could potentially result in adverse impacts to nearby sensitive receptors (if present). Potential sensitive receptors (residences) located near the Koster Road/SR 132 I� intersection could be adversely impacted b localized CO concentrations. For this reason, the SJVUAPCD has recommended that CO modeling be performed to analyze the impact on local CO concentrations at the Koster Road/SR 132 intersection. No sensitive receptors a are located in the vicinity of the 1-5/south-bound on-ramp at Bird Road. Analysis of localized CO concentrations was performed using the fourth generation California Line Source Dispersion Model (CALINE4) developed by the California I� Department of Transportation. Input data for this model includes meteorology, street network geometrics, site data, traffic volumes, and emission generation rates. Carbon 10 monoxide modeling was performed for two scenarios: (1) Existing Plus Project, based on projected Year 1997 traffic volumes and Year 1997 emission factors; and (2) Cumulative Plus Project (worst-case scenario), based on projected Year 2017 cumulative traffic volumes and Year 1997 emission factors. Using 1997 emission factors represents a worst- case scenario, because in the future cleaner burning fuels and improved pollution control !j devices are expected to reduce CO emissions from vehicles. Results of the CO modeling are summarized in Table 4.5-9 and background data is provided in Section 7.5. As indicated in Table 4.5-9, the Existing Plus Project scenario would result in a 1-hour predicted CO concentration of 10.3 PPM and an 8-hour predicted CO concentration of 4.7 i PPM. The Cumulative Plus Project (worst-case) scenario would result in a 1-hour .predicted CO concentration of 10.6 PPM and an 8-hour predicted CO concentration of 4.9 PPM: The Existing Plus Project and the Cumulative Plus Project scenarios would not j exceed the state and federal 8-hour CO standard of 9 PPM or the state 1-hour CO standard of 20 PPM. As a result, localized CO concentrations resulting from mobile source emissions would be a less-than-significant impact for Alternatives 1, 2, and 3. M F Draft Environmental Impact Report 4-79 ER-96-3