"Ranking highest are cities with strong public transit system ridership, well-organized and relatively dense city centers, a high degree of mixed real estate uses (retail, office, residential), and medium-to-high city population density. Honolulu was significantly reduced in the overall ranking by its use of oil for electricity, Boston was somewhat reduced and New York was slightly reduced in the ranking on a proportional basis because of their use of oil for heating.
The highest-scoring cities had strong public transit commute-to-work rates by residents and high overall transit ridership within their metro area. US cities have experienced high growth in rates of telecommuting to work from 2006 to 2007, most likely a direct impact from rising fuel prices. Oakland had the highest telecommuting rate, at 7.6% in 2007, while six US cities-San Francisco, San Diego, Portland, OR; Atlanta; Virginia Beach and Denver--had more than 5% of their total workforce being primarily home based. In 2006 only two cities were above 5% in telecommuting."