The Bay Area Rapid Transit is slowly including the South Bay into its service with the start of construction on Tuesday to prepare for three underground stations.
Construction of the VTA's BART Phase II Project won't be significantly visible in its early stage, but the area of E. Santa Clara and N 3rd Streets will see trucks, drilling equipment and workers operating adjacent to street curbs, in parking spaces, on the sidewalk and in the traffic lane, according to BART and VTA.
The major bulk of the construction on BART extension from Berryessa/North San José through downtown San José to the city of Santa Clara won't begin until early 2020, officials said.
"The work we begin this week for the next seven weeks is preliminary work that will allow us to better understand the soil conditions and where the utilities are placed so that we can advance the design of the tunnel and underground stations," VTA spokesperson Brandi Childress said in a statement.
At least one lane of traffic in the area will be open at all times, Childress said, and the construction noise is described as an equivalent to a lawnmower.
Three new underground stations are planned for Alum Rock/28th Street, Downtown San Jose, Diridon and one ground-level station will be in the city of Santa Clara.