Valley Transportation Authority officials previously believed a construction project to extend BART lines into Santa Clara County would finish in late 2017 — several months ahead of the initially projected completion date. But they acknowledged recently that construction teams are unlikely to meet those optimistic predictions. 

According to a SFGate.com report, the first BART train is expected to open in June 2018, which was the previously scheduled time of completion. Federal transit officials were the ones who originally set the date after helping to cover the $2.3 billion cost of the construction project. 

The 10-mile extension project first broke ground in April 2012. Even as recently as this past year, VTA officials expressed near confidence in the early completion date of late 2017.

The construction project will extend BART lines from Warm Springs in Fremont to Milpitas and the Berryessa neighborhood of East San Jose.