http://ntl.bts.gov/DOCS/473.html
"In almost every instance from 1960-1990, private vehicles captured increasingly larger shares of all metropolitan area work trips. Indeed, private vehicle trips increased from 61% of all commute trips in 1960 to 83% in 1990. In fourteen of the thirty-nine metropolitan areas private vehicles accounted for over 90% of total 1990 commute trips. Also in 1990, transit ridership in metropolitan areas was 9%, while only 5.3% nationally."
-- James Heartfield The 'Death of the Subject' Explained is available at GBP11.00, plus GBP1.00 p&p from Publications, audacity.org, 8 College Close, Hackney, London, E9 6ER. Make cheques payable to 'Audacity Ltd'