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Sight Distance Analvsis The minimum intersection sight distance is based on guidelines described in Chapter 9 -Intersection Sight Distance, in the 2001American Association of State Highway and Transportation Officials (AASHTO) manual, "A Policy on Geometric Design of Highways and Streets". From the AASHTO manual, the minimum intersection sight distance that must be achieved along a roadway with a 45-mile-per-hour speed limit and crossing two lanes is 530 feet. The sight distance available to the driver, exiting the project driveway either to the east or west, is adequate and in excess of the minimum intersection sight distance required in the AASHTO manual. Sight distance for a driver performing a westbound left turn into the project driveway would also have in excess of the minimum intersection sight distance required. Oueuine Analvsis The existing westbound left-turn lane at Fairview Street and Alton Avenue is approximately 410 feet long. The location of the proposed project driveway along Alton Avenue would necessitate shortening the westbound left-turn pocket to a length of 80 feet with an opening of 60 feet. A queuing analysis was conducted using the SYNCHRO traffic analysis soflwaze. The 50`s percentile queue length (average queue length for a typical cycle) for the westbound left would be 44 feet during the morning peak hour. The 95`s percentile queue length (maximum back-of-queue length) for the westbound left would be 83 feet during the morning peak hour. The 50~' percentile queue length for the westbound left would be 36 feet during the evening peak hour. The 95~' percentile queue length for the westbound left would be 73 feet during the evening peak hour. The proposed pocket length of 80 feet would provide adequate storage to serve the westbound left-turn demand. Therefore, the westbound left-turn queue at Fairview Street and Alton Avenue would not be adversely affected by the location ofthe intersection of Alton AvenuelProject Driveway. The queuing analysis also shows that the westbound left-turn queues at Fairview/Alton are not expected to extend to the project driveway intersection. The queuing analysis worksheets are shown in Appendix C. ]N~ture Requirements The City of Santa Ana Transportation Department has expressed concerns regazding the left-turn access into and out of the project driveway and the safety and operation of the intersection for future traffic conditions. If there aze operational problems once the intersection and proposed residential development are in place, the City may require additional analysis. The future analysis would re-evaluate the access, operation, safety, and determine if any intersection modifications aze necessary. Traffic Analysis for - 14 - October, 2007 Alton Court Residential Development 75A-145