75B - PH - TUSTIN AND 4TH ST - Laserfiche WebLink

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7.0 TRAFFIC IMPACT ANALYSIS METHODOLOGY The relative impact of the proposed Project during the AM peak hour and PM peak hour was evaluated based on analysis of future operating conditions at the four (4) key study intersections, without, then with, the proposed Project. The previously discussed capacity analysis procedures were utilized to investigate the future volume -to -capacity relationships and service level characteristics at each study intersection. The significance of the potential impacts of the Project at each key intersection was then evaluated using the following traffic impact criteria. 7.1 Impact Criteria and Thresholds 7.1.1 City of Santa Ana For the study intersection solely under the jurisdiction of the City of Santa Ana, impacts to local and regional transportation systems are considered significant if-. ■ An unacceptable peak hour Level of Service (LOS) at any of the key intersections is projected and the project increases traffic demand at the study intersection by 1% of capacity (ICU increase >_ 0.010). The City of Santa Ana considers LOS D (ICU = 0.801 - 0.900) to be the minimum acceptable LOS for all intersections, except for those locations located within the City's defined major development areas, where LOS E is considered acceptable. Based on the above, the following summarizes the LOS required for the Santa Ana key study intersection: LOS "D"Renuirements 3. SR -55 SB Ramps at Fourth Street LOS "E" Requirements 1. Tustin Avenue at Fourth Street • At unsignalized intersections, an impact is considered to be significant if the project causes an intersection at LOS D or better to degrade to LOS E or F and the traffic signal warrant analysis determines that a signal is justified. 7.1.2 City of Tustin For the study intersection within the jurisdiction of the City of Tustin, impacts to local and regional transportation systems are considered significant i£ ■ An unacceptable peak hour Level of Service (LOS) at any of the key intersections is projected and, for this analysis, if the project increases traffic demand at the study intersection by 1% of capacity (ICU increase >_ 0.010), causing or worsening LOS E or F (ICU> 0.901), the impact is considered significant. The City of Tustin considers LOS D to be the minimum acceptable condition that should be maintained during the peak commute hours at the intersection listed below: 75B-102