• Transportation networks -- roads, bridges, railroads, airports and air traffic control systems, navigable waterways, public transit systems, and so on
• Power networks -- dams, power plants, transfer stations, and power transmission lines. Collectively, this is called "the grid."
• Water supply networks -- dams, pipelines, pumps, wells, reservoirs, water treatment plants
• Waste management -- landfills, sewers, sewage treatment plants
  
• Communications networks -- phone lines, switching stations, cell phone towers, broadband and wireless networks
• Security networks -- this is an emerging infrastructure that is being designed to protect a variety of locations from a variety of perceived threats
  
• Other services we rely on, such as schools, parks, fire and police protection, emergency medical response, and hospitals

Aviation -- Gridlock on America’s runways eased from crisis levels earlier in the decade due to reduced demand and recent modest funding increases. However, air travel and traffic have reportedly surpassed pre-Sept. 11 levels and are projected to grow 4.3% annually through 2015. Airports will face the challenge of accommodating increasing numbers of regional jets and new super-jumbo jets. (Ed. note: Since this was printed, a huge increase in private aircraft have also put an increased strain on the system.)

Bridges -- Between 2000 and 2003, the percentage of the nation’s 590,750 bridges rated structurally deficient or functionally obsolete decreased slightly from 28.5% to 27.1%. However, it will cost $9.4 billion a year for 20 years to eliminate all bridge deficiencies. Long-term underinvestment is compounded by the lack of a Federal transportation program.

Dams -- Since 1998, the number of unsafe dams has risen by 33% to more than 3,500. While federally owned dams are in good condition, and there have been modest gains in repair, the number of dams identified as unsafe is increasing at a faster rate than those being repaired. $10.1 billion is needed over the next 12 years to address all critical non-federal dams—dams which pose a direct risk to human life should they fail.

Drinking Water -- America faces a shortfall of $11 billion annually to replace aging facilities and comply with safe drinking water regulations. Federal funding for drinking water in 2005 remained level at $850 million, less than 10% of the total national requirement.

Energy (National Power Grid) -- The U.S. power transmission system is in urgent need of modernization. Growth in electricity demand and investment in new power plants has not been matched by investment in new transmission facilities. Maintenance expenditures have decreased 1% per year since 1992. Existing transmission facilities were not designed for the current level of demand, resulting in an increased number of ‘bottlenecks’ which increase costs to consumers and elevate the risk of blackouts.

Hazardous Waste -- Federal funding for ‘Superfund’ cleanup of the nation’s worst toxic waste sites has steadily declined since 1998, reaching its lowest level since 1986 in FY05. There are 1,237 contaminated sites on the National Priorities List, with possible listing of an additional 10,154. In 2003, there were 205 U.S. cities with ‘brownfields’ sites awaiting cleanup and redevelopment. It is estimated that redevelopment of those sites would generate 576,373 new jobs and $1.9 billion annually for the economy.

Navigable Waterways -- A single barge traveling the nation’s waterways can move the same amount of cargo as 58 semi-trucks at one-tenth the cost—reducing highway congestion and saving money. Of the 257 locks on the more than 12,000 miles of inland waterways operated by the U.S. Army Corps of Engineers, nearly 50% are functionally obsolete. By 2020, that number will increase to 80%. The cost to replace the present system of locks is more than $125 billion.

Public Parks & Recreation -- Many of our nation’s public parks, beaches and recreational harbors are falling into a state of disrepair. Much of the initial construction of roads, bridges, utility systems, shore protection structures and beaches was done more than 50 years ago. These facilities are anchors for tourism and economic development and often provide the public’s only access to the country’s cultural, historicand natural resources. The National Park Service estimates a maintenance backlog of $6.1 billion for their facilities. Additionally, there is great need for maintenance, replacement and construction of new infrastructure in our nation’s state and municipal park systems.

Rail -- For the first time since World War II, limited rail capacity has created significant chokepoints and delays. This problem will increase as freight rail tonnage is expected to increase at least 50% by 2020. In addition, the use of rail trackage for intercity passenger and commuter rail service is increasingly being recognized as a worthwhile transportation investment. Congestion relief, improved safety, environmental and economic development benefits result from both freight and passenger market shifts to rail creating a rational for public sector investment. The freight railroad industry needs to spend $175-$195 billion over the next 20 years to maintain existing infrastructure and expand for freight growth. Expansion of the railroad network to develop intercity corridor passenger rail service is estimated to cost approximately $60 billion over 20 years. All told, investment needs are $12- 13 billion per year.

Roads -- Poor road conditions cost U.S. motorists $54 billion a year in repairs and operating costs—$275 per motorist. Americans spend 3.5 billion hours a year stuck in traffic, at a cost of $63.2 billion a year to the economy. Total spending of $59.4 billion annually is well below the $94 billion needed annually to improve transportation infrastructure conditions nationally. While long-term Federal transportation programs remain unauthorized since expiring on Sept. 30, 2003, the nation continues to shortchange funding for needed transportation improvements.

Schools -- The Federal government has not assessed the condition of America’s schools since 1999, when it estimated that $127 billion was needed to bring facilities to good condition. Other sources have since reported a need as high as $268 billion. Despite public support of bond initiatives to provide funding for school facilities, without a clear understanding of the need, it is uncertain whether schools can meet increasing enrollment demands and the smaller class sizes mandated by the No Child Left Behind Act.

Security -- While the security of our nation’s critical infrastructure has improved since Sept. 11, the information needed to accurately assess its status is not readily available to engineering professionals. This information is needed to better design, build and operate the nation's critical infrastructure in more secure ways. Security performance standards, measures and indices need to be developed, and funding must be focused on all critical infrastructure sectors, beyond aviation.

Solid Waste -- The nation’s operating municipal landfills are declining in total numbers, but capacity has remained steady due to the construction of numerous regional landfills. In 2002, the United States produced 369 million tons of solid waste of all types. Only about a quarter of that total was recycled or recovered.

Transit -- Transit use increased faster than any other mode of transportation—up 21%— between 1993 and 2002. Federal investment during this period stemmed the decline in the condition of existing transit infrastructure. The reduction in federal investment in real dollars since 2001 threatens this turnaround. In 2002, total capital outlays for transit were $12.3 billion. The Federal Transit Administration estimates $14.8 billion is needed annually to maintain conditions, and $20.6 billion is needed to improve to “good” conditions. Meanwhile, many major transit properties are borrowing funds to maintain operations, even as they are significantly raising fares and cutting back service.

Wastewater -- Aging wastewater management systems discharge billions of gallons of untreated sewage into U.S. surface waters each year. The EPA estimates that the nation must invest $390 billion over the next 20 years to replace existing systems and build new ones to meet increasing demands. Yet, in 2005, Congress cut funding for wastewater management for the first time in eight years. The Bush administration has proposed a further 33% reduction, to $730 million, for FY06.

National structures include federal agencies like the Department of Transporation, the Department of Housing and Urban Development, and the Department of the Interior, which set the broad-scale direction of the country's infrastructure planning. Infrastructure projects with a wide national or regional (that is, multi-state) reach, such as airports and air traffic control, railroads, interstate highways, and big regional water and power projects typically involve these agencies. More recently, the Department of Homeland Security has also moved into this domain, as the country's need for a more solid security infrastructure has emerged.

State structures include the agencies and laws that govern transportation, water resources, industry and agriculture, education, public safety and health, and so on. These entities manage the competition for resources between urban and rural areas; finance and help plan infrastructure in areas that can't afford to build it on their own; and adopt and maintain the building codes and performance standards that infrastructure projects must operate under.

County structures include the building and planning offices, which do large-scale master planning, issue permits for new construction, and enforce the state's building and planning codes. Their master plans, which are the result of a drawn-out public hearing process and developed in consultation with professional planners, are the blueprint for future infrastructure development. They usually specify what new development will be allowed -- and thus, what new infrastructure will be needed at a 10-20 year horizon.

Building codes are typically state laws, though they are enforced at the county level and tend to be roughly uniform around the country. Changes in the code are typically recommended by various trade groups and research universities in response to changes in technology or environmental awareness. Any shift in infrastructure priorities also makes it necessary to change the code: often, things that are essential for the new infrastructure are prohibited by the codes that defined the old. One example would be graywater recovery for use in irrigation -- a tremendous water savings that has been prohibited by most building codes.

National and state standards for power generation, sewage treatment, water distribution, major highway construction, and so on are the "building codes" that define the requirements and set the performance standards for the things we build. "There needs to be A much water, B much power, C much sewer capacity per X number of people. The water quality and supply needs to meet standard Y, and the power quality needs to meet specification Z." These rules usually dictate when and where new infrastructure is needed, and what high-quality output should look like.

Building trades associations and unions, developers' groups, real estate associations, investors' groups, and so on are the "market" part of the structure. Generally, large-scale infrastructure shifts will not happen without their buy-in. Unless they see a profit motive, they can resist needed changes for a very long time. For example: Ten years ago, it was very hard to find a builder who was willing to take the risk with unfamiliar materials and techniques to build an eco-friendly home; or a banker willing to finance one. Now that there's a hot market for such homes, it's becoming much easier to find experienced builders and bankers to work with.

Users, including individuals and businesses: Quality of life and business profits are increased by affordable access to modern, efficient infrastructure. Some businesses may resist change because they rely on their control or mastery of the current infrastructure as a barrier to competition. Some individuals may be hostile to new infrastructure because they fear it will cause social, technological, or economic changes that won't benefit them. Overall, enough users are eager to move forward with more environmentally-friendly infrastructure development to firmly establish this as a baseline trend.

Governments at all levels -- Much (if not most) infrastructure creation is instigated by governments. Governments also do most of the long-range infrastructure planning; establish and enforce the codes and regulations that set the standards for function and performance; arrange for maintenance, upgrading, and repair of existing infrastructure; and issue bonds to finance necessary projects. Despite the trend toward privatization over the past 30 years, government will continue to play a central role in setting the course of future infrastructure development.

Builders and developers who create infrastructure: --Real estate developers, contractors, architects, planners, engineers, transportation companies, and so on. Their interest is in promoting improved infrastructure, because it keeps them in business.

Banks -- Provide funding for infrastructure projects, and create and trade financial products built around these loans.

Employees (both public and private sector) responsible for running the infrastructure -- road maintenance crews, air traffic controllers, teachers, doctors, firefighters, librarians, water quality engineers, power plant employees, railroad workers -- the list is very long. They depend on a continued commitment to good infrastructure for their paychecks, and comprise a significant percentage of the country's workforce.

Universities -- Particularly the public land-grant universities, who have historically done much of the research that has led to infrastructure improvements, and trained the professionals responsible for infrastructure planning, construction, and maintenance.