Well it might be single occupant, but it's often also on the way to another gig. Ignoring that is double-counting.

Counting rideshare cars as "single occupant vehicles" is not "double counting" -- whether I drive in to work and park my car myself, or I take Uber and get dropped off, that's still one trip so it's the same congestion. If he picks up another fare immediately, then that's a new single occupant vehicle trip.

But I think it's rare during commute hours that a ride share driver will drop someone off downtown and immediately find another fare, he's going to have to leave downtown to get his next passenger. So that Uber driver is worse than a single occupant vehicle, he's made 2 trips for one passenger (once to drop me off, once to leave downtown to pick up his next fare).

In off hours, sure, the driver brings someone in, then doesn't have to search far to find someone else looking for a ride, but during commute hours I don't think that's true.

I think some kind of SF congestion tax, with proceeds to benefit public transit infrastructure, would be appropriate.

Crossing the bridges during rush "hour" (more like three to five) should be much more expensive.

Not sure how to handle the fact that this de-facto subsidizes the Peninsula. But it would be a start.