19E - SANTA ANA GRADE SEPARATION PROJECT

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Santa Ana Blvd. Grade Separation discussed later in this report, as it does not meet the project objective. With this, the PDT members elected to study the underpass alternative as the single -build alternative and it was selected as the locally recommended alternative. Refer to Attachment B for the proposed layout, typical section and profile of the locally recommended alternative. 5.1 Alternative Description 5.1.1 Design Parameters The governing standards for the horizontal and vertical roadway alignment alignments are Caltrans and American Association of State Highway and Transportation Officials (AASHTO) standards and practices. Caltrans Highway Design Manual (HDM) was used to determine the minimum inside radius for the horizontal curves and AASHTO's Policy on Geometric Design of Highways and Streets was used for to determine minimum curve length for crest and sag vertical curves. Selected specific design parameters include the following: Design Speed: 45 mph Vertical Clearance: 16' -6" Cross - Section: 100' right -of -way width (minimum) 5.1.2 Horizontal Layout The horizontal alignment of this alternative is based on the standards listed above. The alignment features a slight shift of the roadway centerline to the south to accommodate a utility corridor and a landscaped- retaining -slope area along the northerly right -of -way. The utility corridor will allow the relocation of the water and sewer line and preserves an existing underground electric transmission line. The landscaped- retaining -slope area would reduce the impact of the proposed retaining wall and provide an additional buffer adjacent to the residential properties. Shifting the alignment southward also eliminates the need to acquire right -of -way from residential properties to the north, given there is space available to the south at the City owned SARTC parking area. 5.1.3 Profile This alternative will depress the roadway profile to allow for an underpass bridge that carries the railroad tracks over Santa Ana Boulevard. The proposed profile will join the existing grade at the Santiago Street intersection to the west and the 1 -5 southbound off -ramp to the east. The new Santa Ana Boulevard profile is designed to provide a minimum of 16.5 feet clearance to the soffit of the underpass structure utilizing 6% grades for the approaches. 5.1.4 Cross - Section Santa Ana Boulevard is designed as a six -lane primary arterial with three traffic lanes and a total of 35 feet of traveled way in each direction, plus a 15 -foot median. The northerly parkway will be widened to accommodate the utility corridor and the landscape- retaining- slope area. The southerly parkway will remain at the standard width of eight feet. Landscaping will not be proposed within the southerly parkway. However, a 50 -foot landscaped embankment will be incorporated to the south to eliminate the need for a retaining structure against the SARTC. The 50 -foot buffer will also accommodate future developments including a street car corridor and the SARTC Master Plan. 5.1.5 Adjacent Streets Access from Logan Street to Santa Ana Boulevard will be terminated with a cul -de -sac on Logan Street. The intersection of Fuller Street and Santa Ana Boulevard will be reconfigured PROJECT REPORT EQUIVALENT 19E-17