"Sperling is the co-author (with Deborah Gordon) of Two Billion Cars: Driving Toward Sustainability, a book that considers the environmental impact of so many automobiles and suggests ways that politicians, car companies and the general public can curb car-ownership and reduce climate change."
While most of the talk is on technology, he discuss the roles of transit, land use, and bicycling and car-share. "Mass transit won't solve our energy and transportation problems," states Sperling. The average bus passenger contributes as much greenhouse gases as a car driver because the buses aren't full, he explains.
Wonder which O'Toole he got that data from?