Are there drivers in BART system in san francisco bay area or is it an automatic system ??

Yes there are people driving the trains. If you go to the first car you will see someone up there actually controlling everything from the speed to the doors opening and closing. Every now and then you will actually hear one of them over the speakers making a comment about a delay or problem. I even had a driver one morning coming from Concord point out different spots that people who live here take for granted. For instance when you exit the tunnel, on a clear day you can actually see all four bridges that connect the bay. I had never noticed that until the driver mentioned it.