A consensus study mandated by US Congress to advice on the public policies and investments needed to restore and upgrade the Interstate Highway System to its role as a premier system that meets the growing and shifting demands of the 21st century. Among others, the study will consider future demands on transportation infrastructure determined for national planning purposes, including commercial and private traffic flows to serve future economic activity and growth; long-term deterioration and reconstruction needs; and features that would take advantage of technological capabilities to address modern standards construction, maintenance, and operations, for purposes of safety, and system management.