Overview

• Crews have begun phase two preparations at the west portal in San Jose, installing sound walls and laying foundations for the tunnel-boring machine launch.
• Initial bids for the five-mile single-bore tunnel exceeded projections, prompting VTA to seek a new contractor to keep costs in line.
• The overall tab has climbed to $12.7 billion, with $5.1 billion in federal funding secured but a remaining shortfall of $700 million to $1 billion.
• Engineers are using a top-down construction method to install 82 to 133-foot-deep slurry walls before excavation to navigate challenging soil conditions.
• VTA aims to complete the extension by 2037, connecting BART with Caltrain and VTA light rail at Diridon Station to halve South Bay commute times.