GAO-08-763T, Physical Infrastructure: Challenges and Investment Options for the Nation's Infrastructure
Physical infrastructure is critical to the nation's economy and affects the daily life of virtually all Americans--from facilitating the movement of goods and people within and beyond U.S. borders to providing clean drinking water. However, this infrastructure--including aviation, highway, transit, rail, water, and dam infrastructure--is under strain. Estimates to repair, replace, or upgrade aging infrastructure as well as expand capacity.