Driving to new sources of transportation energy : gaining flexibility, ensuring supply, and reducing emissions.

In July 2002, three Transportation Research Board committees--on Energy, on Transportation and Air Quality, and on Alternative Fuels--held a conference to examine the topics of air quality, global warming, alternative fuels and vehicles, and transportation energy policy. In this article, one of the featured speakers recounts what the experts had to say about hydrogen fuel cells, compressed natural gas, biodiesel, and ethanol; the continuing appeal of petroleum; and setting stricter air quality standards.