Summary: A sound public infrastructure plays a vital role in encouraging a more productive and competitive national economy and meeting public demands for safety, health, and improved quality of life. The federal government has spent an average of $149 billion (in constant 1998 dollars) annually since the late 1980s on the nation's infrastructure. Little is known, however, about the comparability and reasonableness of individual agencies' estimates for infrastructure needs. This report discusses infrastructure investment or "needs" estimates compiled by seven agencies--the U.S. Army Corps of Engineers, the Environmental Protection Agency (EPA), the Federal Aviation Administration (FAA), the Federal Highway Administration (FHWA), the Federal Transit Administration (FTA), the General Services Administration (GSA), and the Appalachian Regional Commission (ARC). GAO focuses on the following infrastructure areas: water resources (inland and deep draft navigation, flood control, and shore protection), hydropower, water supply, wastewater treatment, airports, highways, mass transit, and public buildings. GAO found that the agencies' estimates for infrastructure investments ranged from GSA's calculation of $4.58 billion (in current dollars) over one to five years to repair public buildings to FHWA's estimate of $83.4 billion (in constant 1997 dollars) per year over 20 years to improve highways. The estimates prepared by the Army Corps (for water resources and hydropower) and GSA are for federal spending; the other estimates are for spending from federal, state, and local sources. Each of the seven agencies developed their investment estimate using data from localities, states, or agency regional offices. The estimates, however, were developed using different analytical procedures. The investment estimates cannot be easily compared or simply "added up" to produce a national estimate of infrastructure investment needs because of differences in the methods used, time periods covered, and spending sources. Each of the seven agencies has procedures for developing infrastructure investment estimates that reflect eight practices used by leading government and private sector organizations. No agency has procedures for all eight leading practices.
