Thanks to the election last November, San Jose is getting a legitimate subway system consisting of three stations: Downtown San Jose, Diridon Station, and Alum Rock. Construction is coming sooner than you think. Shovels should hit the ground in late 2018 and continue until 2023. The $4 billion subway is slated to begin service in 2026.
While the idea of a BART subway in our city is very exciting, it will mean epic construction projects, street closures, and all sorts of temporary inconveniences. Currently there are two potential options for building the subway, a single bore (photo below) or twin bore. The SVBJ lists the pros and cons of each, but there is no way around the fact that streets will completely be torn up to build the stations. The tunnels themselves will be deep enough underground to not have a huge impact on the surface.
Other areas up for discussion are whether to build the Downtown San Jose station in the East between Third and Fifth Street (closer to City Hall and SJSU) or in the West between Market and Third Street (closer to the Downtown core). Either option should attract the same number of riders and will permanently change the face of Santa Clara street.
There are obviously a lot of big questions and decisions, but it will certainly be a very exciting decade for South Bay transportation improvements.