They don't use them for the daily AM/PM commutes, anymore. I think that they use a combination of feeds from the CHP, and the various police departments in the region.
They do, however, use them to cover major traffic SNAFUs, or other happenings, that can be described from the air. "As the crow flies," I live about a mile from the Golden Gate Bridge, and 6 blocks from a main artery that leads to it. So, from time to time, I hear the old, familiar Flap-Flap-Flap.
Not sure but a few weeks ago they mentioned having over 400 drones. I was wondering who the hell is flying all those drones but helicopters are very expensive to operate and maintain so it's probably still cheaper.