BART has enough capacity, in form of extra cars, to run longer-than-usual trains following the little accident this morning. AC Transit, the East Bay's bus agency, doesn't have extra capacity, according to this quotation in the Chron:
Johnson said AC Transit, like most of the region's transit agencies, doesn't have a large stock of extra buses or extra personnel that can be mobilized in emergencies.
This is only part of the general infrastructure problem we have in the US, where so many systems - electrical grid, water, etc. - are so fragile that one bad accident can cripple an area.
I also call to your attention the fact that chemical manufacturers have been allowed to drag their feet and block post-9/11 legislation requiring them to shore up security at their facilities. This accident resulted from one 9,000 gallon truck exploding and burning. We have several very large refineries in the Bay Area and, I'm sure, chemical plants. Use your imagination, and then write your congresscritters and ask them to put money into protecting us instead of invading other countries.