Book excerpt: High speed rail (HSR) is being touted as a strategic investment for connecting people across regions, while also fostering prosperity and smart urban growth. However, as its popularity increases, its implementation has become contentious with various parties contesting the validity of socioeconomic and environmental objectives put forward as justification for investment. High Speed Rail and Sustainability explores the environmental, economic and social effects of developing a HSR system, presenting new evaluations of the proposed system in California in the US as well as lessons from international experience. Drawing upon the accumulated experience from past HSR system development around the world, leading experts present a diverse set of perspectives as well as diverse contexts of implementation. Assessments of the California case as well as cases from Japan, France, Germany, Italy, Spain, Taiwan, China, and the UK show how governments and stakeholders have bridged the gap between the vision and the realities of connecting metropolitan regions through HSR. This is a valuable resource for academics, researchers and policy-makers in the areas of urban planning, civil engineering, transportation and environmental design.