And those stats aren't suitable for this purpose (they're undercounting my millions more), as there are many one parent households, plus many parents who live in a household with others but who don't own cars themselves.
2 person households, 38 million with 1+ cars, 2 million without.
4+ person households are almost as likely to have 4 or more cars as 0 or 1 cars.
Single person households are almost as likely to have 2 or more cars as no car at all. (The dominant number of vehicles by far is, of course, 1.)
Of the 85 million households with more than one person, only 3 million have no cars at all. You can "undercount" and adjust all you want, you're talking 5%, maybe 7% maximum of "parents without cars."
Of course it's possible, in a few scattered geographic areas with high density and convenient public transit. But that's not almost any of America.
In 2017, the American Communittmy Survey showed that of the 46m households with 3+ people, approximately 44 million had 1 vehicle and 16 million had 3 or more vehicles.
If you see two parents and a child in America, it's more likely one of them thinks the moon landing is a hoax than that they do not own a car.
Who lives in a bubble?
https://factfinder.census.gov/bkmk/table/1.0/en/ACS/17_5YR/B...