Are Americans ditching their cars?

The answer to that question in City Lab is "no":

...Research that I summarized in my report “The New Automobility” last summer showed that ride-hailing growth has led to more traffic and less transit use in major American cities—not the reverse that we all hoped for.

Uber, Lyft, and advocates for new shared mobility services have pushed back against this analysis. Declaring that we are still at the “earliest stages” of a major shift in travel habits, they look to the day that people ditch their car in favor of a combination of these services and old-fashioned public transportation. Their vision is that diminished car ownership and fewer miles in privately owned vehicles will more than offset added mileage from ride-hailing vehicles...

Increased car ownership in America’s most walkable and transit-oriented cities is a deeply worrisome reversal from what came before. From mid-2000 to 2012, transit ridership increased while car ownership grew slowly, if at all. But now car ownership is expanding faster than population. Add in ride-hailing services, and the glut of motor vehicles makes it more difficult to give buses, bikes, and now e-scooters the road space they need to be speedy, safe, and comfortable...

From CBS San Francisco:

...In San Francisco, a study released in June[2018] found that on a typical weekday ride-hailing drivers make more than 170,000 vehicle trips, about 12 times the number of taxi trips, and that the trips are concentrated in the densest and most congested parts of the city.

   And a survey released in October of more than 4,000 adults in Boston, Chicago, Los Angeles, New York, the San Francisco Bay Area, Seattle and Washington, D.C. also concluded that 49 to 61 percent of ride-hailing trips would have not been made at all — or instead by walking, biking or public transit — if the option didn’t exist...