Appendix H - Transportation Supporting Information COMBINED

Transportation Impact Study for Hidden Canyon Residences & Preserve March 2023 Page | 14 2.2 SIGNIFICANT IMPACT CRITERIA The criteria for determining the significance of project impacts is based on City of Pleasanton performance standards identified in the Pleasanton General Plan and utilized in prior transportation impact studies. Traffic Impact Criteria City of Pleasanton LOS standard specify that the minimum acceptable operation for signalized intersections is LOS D. The following study intersections are designated as Gateway intersections: 4. Dublin Canyon Road-Canyon Way & Foothill Road (Signalized) 5. Foothill Road & I-580 Eastbound Off-ramp (Signalized) 6. Foothill Road & I-580 Westbound Off-ramp (Signalized) 9. Stoneridge Drive & I-680 Southbound Off-ramp (Signalized) 10. Stoneridge Drive & I-680 Northbound Off-ramp (Signalized) At study intersections that are not designated as Gateway intersections, project impacts would be considered potentially significant if the Project results in: • Deterioration of a signalized intersection form LOS D or better to LOS E or F; or • An intersection projected to operate at LOS E or LOS F prior to the addition of project traffic, the project adds 10 or more vehicle trips; or • Deterioration of controlled movement at an unsignalized intersection from LOS E or better to LOS F, or at unsignalized intersections where a controlled movement already operates at LOS F and results in one of the following: o Project traffic results in a volume that meets the peak hour traffic signal warrant; or o Where the peak hour signal warrant is met without the project and delay cannot be measured, project traffic increases the volume by 10 or more vehicles per lane on the controlled approach; or o Project traffic increases average delay to a minor movement by more than 30 seconds At each of the Gateway intersections: The level service may be lower than LOS D if no reasonable mitigation exists or if the necessary mitigation is contrary to other goals and policies of the City. For example: the Circulation Element of the General Plan notes that road widening and elimination may result in a loss of visual character and pedestrian convenience at such intersections. The Circulation Element also notes that improvements to LOS may also encourage additional cut-through traffic, thereby reducing the LOS downstream of those intersections. At all study intersections: project impacts would be considered potentially significant if the project were to conflict with an applicable congestion management program, including but not limited to LOS and travel demand measures, or other standards established by the Alameda County Congestion Management Agency for designated roads and highways.