The document presents a plan from the California Secure Transportation Energy Partnership (CalSTEP) to reduce California's dependence on petroleum and increase the use of alternative transportation fuels. The plan aims to reduce petroleum use for on-road transportation 15% below 2003 levels and increase the proportion of alternative fuels to 20% by 2020. It proposes three primary actions and seven supporting actions across diversifying fuels, improving efficiency, and reducing driving needs. The actions together could reduce petroleum use by 7.6 billion gallons and greenhouse gas emissions by 62 million tons annually, while strengthening the economy and environment.