That is cool. I love how all the traffic is just going this way and that way, including pedestrians. The Market Street line is electrified now. The cable cars are now mostly used for the very steep routes. Market Street is relatively flat in a city of steep hills.
I've seen comments from a few people, elsewhere, thinking they're seeing trackless trollies. But if dated correctly, there were none in SF when this was filmed. Boxcab E50
They are certainly not trackless. It's hard to see on the lines crossing, but there are tracks. They just get lost in the contrast limitations of the film used and the subsequent processing.