The document provides information about San Francisco International Airport's (SFO) efforts to promote green vehicles and reduce emissions. It notes that SFO serves over 45 million passengers per year and has policies requiring ground transportation services to use clean vehicles like CNG, electric, or hybrids. Over 2,000 taxis and 600 permitted vehicles at SFO use alternative fuels. SFO also offers employee incentives to take public transit and is upgrading passenger terminals to be more energy efficient.