The new Warm Springs Extension alignment will parallel portions of the Union Pacific (UP) railroad corridor, which contains the former Western Pacific (WP) and Southern Pacific (SP) railroad tracks, and Interstates 680 and 880 in southern Alameda County.
The initial segment will begin on an embankment at the southern end of the existing elevated Fremont BART Station, pass over Walnut Avenue on an aerial structure, and descend into a cut-and-cover subway north of Stevenson Boulevard. The alignment will continue southward in a subway under Fremont Central Park and the eastern arm of Lake Elizabeth, and surface to at-grade between the former WP and SP alignments north of Paseo Padre Parkway.
Paseo Padre Parkway is currently being reconfigured as a vehicular underpass as part of the City of Fremont's Grade Separations Project. Read more on Fremont Grade Separations Project. The alignment will pass over Paseo Padre Parkway on a bridge structure, and continue southward at-grade, passing under a grade-separated Washington Boulevard. Additionally, Washington Boulevard will be reconfigured as a vehicular overpass as part of the City's grade separation project. From Washington Boulevard, the alignment will continue at-grade along the former WP alignment south to a terminus station at Warm Springs and South Grimmer Boulevards in the Warm Springs District.
The distance from the Fremont station to the Irvington station is 2.4 miles. The distance from the Irvington station to the Warm Springs station is 2.23 miles. The remainder of the extension, approximately .77 miles, includes tail track for maintenance.
