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Redwood City Costco Gasoline Expansion ProjE 7.A. - Page 256 August 20,2012 ruye vv Recommended Redwood City Expansion Trip Generation Estimate The five approaches outlined above result in a trip generation estimate range varying from 430 total weekday p.m. peak hour trips to 660 total weekday p.m. peak hour trips.A side by side comparison of the trip generation estimates resulting from the five approaches is provided in Table 21. Table 21 Comparison of Five Trip Generation Approaches -Weekday PM Peak Hour Weekday PM Peak Hour Trip Generation Estimate—Total Trips Approach#1- Approach#2- Approach#3- Approach#4- Approach#5- Based on Based on Highest Based on Based on Based on ITE Equal or Greater Observed 5 Island Before&After Straight Linear Manual Trip Activity Sites Location Data Increase Generation Total Trip Ends 430 500 440 660 510 Internal Trips(22%PM) (90) (110) (100) (140) (110) External Trips 340 390 340 520 400 Pass-by Trips(22%PM) (70) (80) (70) (110) (90) Diverted Trips(59%PM) (200) (230) (200) (300) (230) Net New Trips 70 80 70 110 80 It is clear from all of the data presented that Approach #4 (660 total weekday p.m. peak hour trips) is unreasonable and unrealistic. The data indicates that trip generation is not directly linear with number of fueling positions. Furthermore, applying that approach yields an estimate that is 32% higher than the actual trip generation observed at any existing Costco Gasoline location where actual trip count data has been collected (including sites with significantly more activity than that of Redwood City). All other approaches lead to quite similar estimates when comparing the resultant net new weekday p.m.peak hour trip ends. While the trip generation estimates resulting from Approaches #1 and #3 are likely reasonable, to be conservative we recommend that the trip generation estimate developed using Approach #2 (the highest observed trip generation at an existing 5 island location and which also happens to be essentially the same as applying the ITE trip generation manual trip rates) be used for the evaluation of the Redwood City Costco Gasoline expansion. While this is likely an overestimation of the trip generation impacts given the relative activity at that site compared with Redwood City, it will ensure the analysis is conservative and extremely defensible. The recommended trip generation estimate for the proposed Redwood City Costco Gasoline expansion project is summarized in Table 22. Kittelson&Associates,Inc. Boise,Idaho