Interstate 215 Garbani Road Interchange Project

The City, in cooperation with Caltrans, proposes to construct a new interchange at I-215 and Garbani Road. The project site is located in the City of Menifee between PM R15.5 and PM R17.5. The new interchange would be located approximately 1 mile north of the Scott Road Interchange and approximately 2 miles south of the Newport Road Interchange. Garbani Road currently features discontinuous connectivity in the east-west direction due to I-215, which bisects Menifee. The proposed project would improve transportation circulation and connectivity in the area by reconstructing Garbani Road to provide continuous multimodal travel across I-215 and constructing a new I-215 interchange at Garbani Road. The following three alternatives are being studied in the EIR for this project: Alternative 1 – No-Build Alternative Alternative 2 – Compact Diamond Interchange Alternative 3 – Spread Diamond Interchange Alternative 4 – Diverging Diamond Interchange Alternative 1: No-Build Alternative Under the No-Build Alternative, the existing transportation facilities within the project area would remain unchanged, except for planned and programmed improvements being implemented as separate projects by other entities. This alternative does not address the purpose and need of the project. The No-Build Alternative represents the baseline alternative and offers a basis for the analysis and evaluation of the Build Alternatives. Alternative 2: Compact Diamond Interchange Build Alternative 2 includes construction of a new diamond configured interchange along I-215 at Garbani Road, and improvements to Garbani and Antelope Roads. Build Alternative 2 includes four diagonal northbound and southbound on- and off-ramps. The ramp terminal intersections would be signal controlled four-way stop intersections, or unsignalized roundabouts. Auxiliary lanes from the Scott Road interchange directly south of the project would be extended to the Garbani Road interchange northbound off-ramp and southbound on-ramp. The proposed improvements on Garbani Road include reconstruction to a continuous Major (4-Lane) roadway between the Haun Road intersection west of I-215 and the Champagne Drive intersection east of I-215, consistent with the City’s General Plan designation for Garbani Road. The roadway characteristics would be consistent with the City’s roadway standards to include four 12-foot-wide travel lanes, a 12-foot-wide raised median/left-turn lane, two 8-foot-wide Class II bicycle lanes, and two 6-foot-wide sidewalks. In addition, a 10-foot-wide regional trail is proposed along the north side of Garbani Road consistent with the City’s Community/Regional Trail standards. Under Alternative 2 the portion of reconstructed Garbani Road that would be a bridge over the I-215 is approximately 108 feet wide and 204 feet long. The Garbani Road bridge over I-215 would include four 12-foot-wide lanes, 24-foot-wide median/double left-turn lane pocket, two 8-foot-wide bike lanes, a 12-foot-wide sidewalk on the north side, and a 6-foot-wide sidewalk on the south side. The proposed improvements along Antelope Road include upgrade of the road to a Major (4-Lane) Road with four 12-foot-wide lanes, a 12-foot-wide median/left-turn lane, two 8-foot-wide bike lanes, and two 6-foot-wide sidewalks. Antelope Road would be realigned approximately 3,840 feet to the east. The relocated Garbani/Antelope Roads intersection would be a signal controlled intersection or an un-signaled roundabout. Alternative 3: Spread Diamond Interchange Build Alternative 3 includes construction of a new spread diamond interchange along I-215 at Garbani Road. The configuration includes four diagonal northbound and southbound on- and off-ramps that would be signal controlled or roundabouts, similar to Build Alternative 2. Auxiliary lanes from the Scott Road interchange directly south of the project would be extended to the Garbani Road interchange northbound off-ramp and southbound on-ramp. The primary difference between the designs is that the spread diamond configuration is a larger footprint that at a future time could accommodate the addition of a loop on-ramp if traffic conditions past the 20-year horizon year would require it. The proposed Garbani Road bridge over I-215 under Build Alternative 3 is approximately 88 feet wide and 204 feet long. The bridge includes four 12-foot-wide lanes, a 4-foot-wide median, two 8-foot-wide bike lanes, a 12-foot-wide sidewalk on the north side, and a 6-foot-wide sidewalk on the south side. Build Alternative 3 would share the same proposed improvements to Garbani and Antelope Roads as under all build alternatives, which are described above under Build Alternative 2. Alternative 4: Diverging Diamond Interchange Build Alternative 4 includes construction of a new diverging diamond interchange (DDI) along I-215 at Garbani Road. The DDI configuration would include two signalized ramp intersections and a configuration that allows for direct left turns to freeway on-ramps. Auxiliary lanes from the Scott?Road interchange directly south of the project would be extended to the Garbani Road interchange northbound off-ramp and southbound on-ramp. The Garbani Road bridge over I-215 proposed under Alternative 2 is approximately 92 feet wide and 204 feet long. The bridge includes four 12-foot-wide lanes, two 8-foot-wide bike lanes, two 4-foot-wide shoulders, and a barrier-protected 16-foot-wide regional trail and sidewalk path, which converges along the center of the interchange. Build Alternative 4 would share the same proposed improvements to Garbani and Antelope Roads as under all build alternatives, which are described above under Build Alternative 2.