A place like SF is well suited for trolley buses - it has steep hills, heavy passenger loads, lots of stops and very little freeway speeds on most of the bus lines. The big problem has always been the overhead switches and other special works and dewiring of the poles. Batteries might make some redesign of the overhead possible.

Trolley coaches were suggested in the recent past for some lines in the Eastbay but that area just gets the shaft when it comes down to transit disinvestment. The BAERA used to meet in Berkeley in the sixties but the interest in electric transit never seemed to perk down to the townies and functionaries.

As far as fires go I was motivated by the recall of several "roundhouse fires" that wrecked some precious equipment. Those battery fires seem to be high temperature and stubborn; I was concerned about fast spreading in a vehicle storage area.