Why?
Check their web site for details. It's designed to offer a window into the historic work being done on the Bay Bridge– from the retrofitting of the original West Span, to the demolition and replacement of the West Approach, to the construction of the new Skyway and dramatic single tower Self-Anchored Suspension (SAS) span>>>.
During the Labor Day weekend, BART will operate on its normal weekend timetable. On Labor Day, BART will operate on a Saturday schedule. However, after midnight, the hourly, overnight service to the 14 stations will start around 1 a.m. and continue until roughly 6 a.m. on Saturday, September 1, until 8 a.m. on Sunday, September 2nd and until 6 a.m. on Labor Day, Monday, September 3rd.>>>