The document discusses various modes of transportation and their environmental impacts. It describes how some cities are reducing traffic and pollution by charging cars to enter the city, like London's $16 fee. It also discusses the efficiency of hybrid vehicles like the Toyota Prius compared to average US vehicles, and the types of hybrids that exist. New York and San Francisco are working to convert their taxi fleets to hybrids. Well-designed public transport systems that combine rail, buses, bike lanes and walking paths can provide low-cost, sustainable mobility. Japan's bullet trains are also discussed as a popular green transportation option.