Item 21 - Memorandum of Understanding with OCTA and City of Irvine

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-1 OF 14 A. L a 'Zfi IBC VISION PLAN 2o18 TRAFFIC STUDY UPDATE - ALTERNATIVES ANALYSIS Final 3.7 Alternative 2 Future Improvements and Mitigations Table 3.6 shows the number of significantly impacted locations for arterials, intersections, freeway mainline and ramps. Because the land -use is identical and there is only one roadway network difference between the Alternative 2 and Buildout Cumulative With Update scenarios, there are few significant impacts observed. Improvement strategies for each are discussed in turn. Table 3.6 — Alternative 2 Number of Impacted Locations in the Study Area FACILITY ALTERNATIVE 2 Arterial Segments 0 Intersections 2 Freeway Mainline 0 Freeway Ramps 1 Total 2 Intersections Deficient intersections within the IBC study area fall under two categories: significant impact and cumulative deficiency. Impacts are determined using the definition of significant impacts from each city's traffic impact analysis protocol, presented in Chapter 2 of the 2018 IBC Vision Plan Two -Year Traffic Study Update. For the cities of Costa Mesa, Santa Ana, and Tustin, significant impacts are identified as an increase in intersection ICU of 0.01 or greater under With Update conditions of a deficient intersection when compared to Baseline conditions. For the City of Newport Beach, an impact is identified as an increase of 0.01 or more of the critical movement of a deficient intersection. Cumulative deficiencies are identified as those intersections that fail under both the Baseline and With Update conditions but do not have an update impact as identified by the above noted criteria. The City of Irvine threshold for defining impact is degradation of an intersection from acceptable to deficient LOS, or for a location already deficient in the baseline, an increase of 0.02 or greater of an intersection ICU. For intersections with shared jurisdictional boundaries, the more conservative methodology was employed. Twenty-four intersections under Alternative 2 are forecast to operate at a deficient LOS. Of those deficient intersections, a significant impact is forecast for two intersections in Alternative 2 and require intersection improvements. Table 3.7 identifies intersections with significant impact deficiencies for the Alternative 2 scenario studied. Table 3.7 —Alternative 2 Intersections Significantly Impacted in the Study Area 719 Flower Street at Segerstrom Santa Ana Yes 720 Flower Street at MacArthur Boulevard Santa Ana Yes Total Number Locations 2 Source: ITAM, City of Irvine, ICU analysis ''� ••�•• ........ Iteris, Inc. 182