BART hopes to run a test car on the agency's tracks without passengers as early as next month. The car will be tested for another four months of performance monitoring after that initial test.
But, the transit agency has cut the number of expected cars it will roll out to 35, down from the original plan of 60 cars.
BART had hoped to roll out 230 cars by the end of next year, but the revised number is now 166 cars.