Traveling between cities by high-speed rail uses as much as a third less energy per passenger-mile than the same trip by car. The United States currently has just one high-speed line–a 735-kilometer system serving Boston, New York City, and Washington, DC. The Obama administration is investing $8 billion to jump-start the development of 10 high-speed rail lines around the country, but no firm date for construction has been set. Meanwhile, Europe is planning a significant expansion of its high-speed rail network: 8,000 kilometers are due to be added in Spain alone by 2020. Most ambitious of all is China, which announced in September that it plans to construct 42 high-speed lines, totaling 13,000 kilometers, by 2012.