"Downtown SF has very little parking relative to demand, so Uber / Lyft are practically the only way to get there in a car."

So, wait... Your argument is that there is a natural disincentive to go downtown with a car, unless one uses Uber or Lyft... But you also somehow doubt that the car traffic that is downtown has been caused by Uber and/or Lyft?

So is everyone an idiot because they just drive around downtown, give up, and go home? Or they aren't in on this Uber/Lyft secret that nobody has heard about?

Or... And I'm just spit-balling here... Maybe you just argued against yourself very effectively.

My point was actually that the traffic is already relatively self-regulating due to the lack of parking, most people don’t get there by driving. Sure it’s plausible that Uber or Lyft increased the traffic, but it’s difficult to assert that in an alternate universe without Uber or Lyft that more parking would not have been built (attracting more cars), or that you’d have more traffic from cruising (people hunting for parking). Development plays a huge role as well, perhaps Uber has allowed more development than would have been feasible without it, or perhaps all the new development would have happened anyway, either way it’s a complex adaptive system that you can’t easily just say “ah, THIS is the one and only cause.”

The fact that it’s extremely difficult or impossible to control for these things doesn’t mean that any analysis which doesn’t control for these things is valid or useful.

>Downtown SF has very little parking relative to demand, so Uber / Lyft are practically the only way to get there in a car.

Why do you need to get there in a car?

Is this a trick question?

I use Muni and Caltrain.