Appendix H - Transportation Supporting Information COMBINED

Transportation Impact Study for Hidden Canyon Residences & Preserve March 2023 Page | 40 6.0 CUMULATIVE CONDITIONS This section details provides an assessment of potential cumulative transportation impacts resulting from the project. Cumulative Conditions reflects a long-term horizon with buildout of the City’s General Plan. 6.1 CUMULATIVE TRAFFIC VOLUMES WITH GENERAL PLAN BUILDOUT City staff provided the anticipated peak-hour traffic volumes, and planned changes to lane configurations at freeway ramp intersections on Foothill Road/I-580 and Stoneridge Drive/I-680, at study intersections under Cumulative plus Project conditions from the City’s travel demand model. The forecast of Cumulative No Project traffic volumes is based on General Plan buildout that includes the proposed project. TJKM estimated the Cumulative Plus Project traffic volumes based on the trip generation, distribution and assignment applied to the analysis of Existing plus Project Conditions and Near Term plus Project Conditions. The anticipated volume of peak-hour traffic applicable to the project at each study intersection was subtracted from the Cumulative plus Project volumes to provide a forecast of Cumulative No Project. Figure 14 shows projected peak hour turning movement volumes at all of the study intersections for Cumulative No Project Conditions. Figure 15 displays projected turning movement volumes at all the study intersections for Cumulative plus Project Conditions. 6.2 CUMULATIVE IMPACT FINDINGS WITH PROPOSED PROJECT The intersection LOS analysis results for Cumulative Conditions are summarized in Table 8. Detailed LOS reports for Cumulative No Project Conditions are contained in Appendix G. Detailed LOS reports for Cumulative plus Project Conditions are contained in Appendix H. The intersection LOS analysis results for Cumulative No Project and Cumulative plus Project Conditions are summarized in Table 15. Based on this analysis: all study intersections are forecasted to continue to operate acceptably at LOS D or better under cumulative conditions, with or without the proposed project. During the a.m. peak hour the stop-sign controlled intersection of Schaefer Ranch Road & Dublin Canyon Road experiences would experience delay consistent with LOS F on the stop-sign controlled approach (southbound Schaefer Ranch Road approaching Dublin Canyon Road) under both Cumulative No Project and Cumulative plus Project Conditions. Side-street approach volumes on Schaefer Ranch Road would exceed the peak-hour signal warrant, as is the case under Existing Conditions, with or without the proposed project. The project is not anticipated to add traffic to the controlled approach. Average delay to the stop-sign controlled approach would increase by less than two second due to the project. Therefore, the project would not increase delay to a minor movement at an unsignalized intersection operating at LOS F by more than 30 seconds. Overall average delay for the intersection would remain consistent with LOS A. With installation of a traffic signal at the intersection of Dublin Canyon Road with Canyon Meadows Drive (which is being coordinated between the developer and the City to enhance traffic operations and safety), the intersection is expected to continue to operate at LOS A during both peak hours.