This section summarizes some local tunneling projects constructed in geologic conditions similar to the various zones being considered for the SR-710 Tunnel. These local projects include the NEIS, the ECIS, and the Metro Red Line and Gold Line Eastside Extension. The NEIS tunnel is located in and south of Zone 1 and other tunnels are located south of Zone 1. Histories from these tunnels provide information about tunneling in similar geology as well as lessons learned from challenges encountered and overcome in the previous projects.
Figure 12-1 shows these local projects in relation to the SR-710 study area.