This computer graphics simulation shows how the BART-eBART transfer station would work. eBART uses modern European DMU running at conventional track, providing BART-level performance that is an order of magnitude less expensive.
For a real-word example, the following video was taken (from wheelchair point-of-view) of the newly opened San Diego Sprinter, which uses DMU equipment similar to what is proposed for eBART. Note that the 22-mile Sprinter project is at least 10 times less expensive than the 22-mile BART-San Jose extension.