As the author of the piece explains, this is proof that:
the notion that Millennials are spurning cars across the board is clearly oversimplified. In many big cities, young people today are commuting in much the same way they did three decades ago—tape decks notwithstanding.
Why 1980? Because using 1990 or 2000 data would show that there is in fact a trend in young people away from commuting by car.
This is just my opinion, but I feel like this story is lazy journalism because it doesn’t include important context. A lot was different back in 1980; for example, transit ridership in general was higher than today. There were a lot of roads built and cars sold during the 80s and 90s. A lot!
But anyway, still interesting I guess.