Construction updates, from north to south:
Construction will begin this fall in the Fremont station. It will include extending the station's embankment to Walnut Ave., and building a bridge over that street for the BART line.
The northeast lobe of Lake Elizabeth has been restored.
The Warm Springs station is taking shape. What it will look like: Station Photo Sims 2012 - Warm Springs Extension - Picasa Web Albums
Some of its support pillars are now in place, and it is getting an upper floor. From these conceptual pictures, the station will have its tracks at ground level and its concourse on a floor above it. On top will be a big awning.
It will be to the east of the UP / ex-WP / ex-SP line. The big street near it in the pictures is South Grimmer Blvd., just to the north of it, and that street has some construction alerts. Crossing that street are two railroad bridges. The eastern (ex-WP) one may be removed to make way for a BART bridge.
North of the Milpitas station, a trench has been built for the BART line. This trench will continue into the station, and the station will be very near the Montague light-rail station.
The Berryessa station now has some support pillars for its elevated trackway. The line will run over Berryessa Rd. and Mabury Rd.; the station will be in between.
from Warm Springs to Berryessa -- it shows the BART line's elevation relative to its surroundings. North of the Milpitas station, the BART line will go over the roads, likely because the UP / ex-SP will either also do so or cross them at grade. South of the Milpitas station, the BART line will go under the roads, because it will be following the UP's ex-WP line. Will it be abandoned and taken over by BART? That's what happened to the ex-SP branch from San Bruno to Daly City.