The funding could be as much as US$4.6bn (£3.75bn), if needed for the alignment that will extend the heavy rail service from Berryessa/North San Jose through Downtown San Jose into Santa Clara. The Federal Transit Administration (FTA) approval allows VTA to apply for twice the amount of funding anticipated under the previous Expedited Project Delivery pilot program. The FTA’s action also approves past eligible expenses for potential grant reimbursement back to March 2016, as well as for all remaining work on the project, for the estimated total project cost of up to US$9.3bn (£7.5bn).

In May, Kiewit Shea Traylor joint venture (KSTJV) was awarded the design-build contract for the tunnel and trackwork. KSTJV plans to procure an approximate 16.5m (54ft) diameter TBM to bore an 8km (5-mile) tunnel under Downtown San Jose. It is the first rail project in the US to be constructed by a single bore, allowing both tracks and station platforms to be constructed within the tunnel.

In November, an independent peer review, led by the American Public Transportation Association, concluded that a single-bore tunnel was the best option for the project. It said it would save construction time, reduce the station footprint and property needs, increase the potential for transit-oriented development, and reduce disruption to communities.

VTA plans to begin the federal funding application next summer, after completing a final cost estimate and funding plan. VTA is seeking an additional US$750m (£612m) from the state’s transportation funding program for major transit projects as the last key funding piece.

The Phase II extension includes 9.6km (6 miles) of track and four stations to be added to the Phase I (16km) 10-mile alignment from the Warm Springs/South Fremont Station, through Milpitas and Berryessa/North San Jose.