They criss-cross underneath our cities and country sides, yet most of the time we are not even aware they are there. They deliver critical fuel that powers our homes, factories, and offices; and also transport the oil and gas that keep our cars, trucks, and planes operating. The nation's 2.5 million mile network of hazardous liquid and natural gas pipelines includes more than 400,000 miles of "transmission" pipelines, which transport products from processing facilities to communities and large-volume users. To minimise the risk of leaks and ruptures, the Pipeline and Hazardous Materials Safety Administration (PHMSA) requires pipeline operators to develop incident response plans. Pipeline operators with pipelines in highly populated and environmentally sensitive areas are also required to consider installing automated valves. This book examines the ability of transmission pipeline operators to respond to product release, with a focus on the advantages and disadvantages of installing automated valves in high-consequence areas and safeguarding the public.