A ‘data column’ from the Seattle Times.  (Note the irony of the header.)

Has Seattle reached “peak car”?
When it comes to the rate of ownership, it sure looks that way.
Census data show that from 2010 to 2015, the percentage of Seattle households that own a vehicle declined — that’s noteworthy because it’s something that hasn’t happened in decades.
I checked the data back to 1970. Car-ownership rates have creeped up every 10 years, right through to 2010. That year, 84.6 percent of city households owned at least one vehicle.
But suddenly, that number is dropping. As of 2015, it’s down by about 1 percentage point. And that’s almost entirely because of one group.
Seattle Times 2
It’s a combination of economics and priorities, says Mark Hallenbeck, director of the Washington State Transportation Center at the University of Washington. As Seattle housing costs go through the roof, he says, cars are one expense that many young city dwellers are willing to sacrifice.
“If you get away from the high set of fixed expenses that go with owning a car — monthly payments, parking, insurance — you can pay for the apartment that allows you to live on Capitol Hill,” he said. “You can go out to bars to meet your friends, and you can get around everywhere you need to go.” …
A deeper look at the numbers shows that from 2010 to 2015, under-35 households without a car in Seattle — there are more than 17,000 of them — increased at a 10 times faster rate than those that do have at least one car.
That said, cars aren’t going away anytime soon in Seattle, a city that famously loves its Subarus and Priuses. Many Seattleites, even if they don’t drive much, still want to own a set of wheels for weekend excursions.
And in terms of the raw number of cars, Seattle probably hasn’t hit its peak. Even though carless households are growing faster, households with cars are still increasing, including those that own multiple cars. These forces pushed the city’s car “population” to 435,000 in 2015.