The problem remains a mystery: what caused BART's mysterious voltage spike between N. Concord and Bay Point Stations?
It's been almost a month since the first voltage spikes occurred, slaughtering "C" cars and taking them out of service. Normal train service has resumed, first with just "A" and "B" cars, but now includes "C" cars once again.
So the problem is gone for now - but BART still has not managed to diagnose the problem. Paul Oversier, Assistant General Manager of Operations, said, "...We need to get to the bottom of this. We don't want our customers to suffer through another round of this so we need to get to the root cause."
BART has developed a car specifically designed to measure track voltage at various locations, but still nothing. Only time will tell.