Wikipedia says that BART has 59 A cars and 389 B cars, all built from 1968-1971. That means for every A car, there are 6.5 B cars. How is this possible? Were some of the A cars converted to B cars after the purchase of C cars?
https://www.youtube.com/channel/UCXu4mb ... 8cuxblPB9g Videos, including SEPTA time lapses.