Homeowners in Bowie or Rockville perceive little connectivity with homeowners in Alexandria or Falls Church. Homeowners in Wheaton or Laurel, facing their own problems, are unconcerned with homeowners’ problems in Annandale or the District. Yet they have a shared interest and interconnection: infrastructure.

Regrettably, fragmented thinking in metropolitan Washington, reinforced by fragmented government, is a major obstacle to comprehending and dealing with infrastructure, so much of which is failing, obsolete, inequitably distributed and potentially dangerous.

Most residents of Maryland, Virginia and the District think locally, not regionally. Taking infrastructure for granted, they are content as long as their home has electricity, natural gas, water and sewer service. They expect local government to worry about draining stormwater and disposing of solid waste. They feel entitled to have access to drivable roads, public transit, good schools and well-landscaped parks, which is why they pay property and sales taxes.

They likewise assume that distant infrastructure functions effectively: seaports and airports; railways and train stations; pipelines and refineries; power plants and electrical networks; water and sewage treatment facilities; and flood control systems. They count on systems that they believe reliably safeguard and distribute the nation’s people, goods and energy.

Yet they may not realize that no matter where they live, they are, in fact, linked to everyone else because they are plugged into a local, regional and national infrastructure matrix. Their home, their neighborhood, their town, city or county all depend, to some extent, on this complex matrix. They also may not appreciate infrastructure imbalances, places in the city plagued by inadequate or highly degraded infrastructure.

(Roger K. Lewis/For The Washington Post)

Infrastructure performance reliability cannot be taken for granted. America’s civil engineers have given American infrastructure an overall grade of D+ — emblematic of the often hidden effects of deferred maintenance, technological obsolescence and woefully insufficient public-sector investment. A D+ means America’s infrastructure is more apt to fail and become more dangerous.

Dramatic collapses reveal structural weaknesses in aging bridges. The recent natural gas explosion in New York’s Harlem is a reminder that volatile energy distribution networks are deteriorating, especially in older and less affluent neighborhoods.

Tragically destructive impacts of natural events — Hurricanes Katrina and Sandy, tornadoes in the Midwest, earthquakes and drought in California, storm-caused electric power outages lasting days — highlight infrastructure vulnerability. And mounting scientific evidence shows that global climate change exacerbates threats to infrastructure.

To explore infrastructure challenges and solutions, journalists from across the country attended a two-day forum last week in Cambridge, Mass., sponsored by the Lincoln Institute of Land Policy, the Harvard University Graduate School of Design and the Nieman Foundation for Journalism at Harvard. Stimulating presentations and discussion focused on forum topics such as infrastructure resilience, security and financing.

The forum also addressed technological innovations and design strategies for helping solve infrastructure problems. For example, one cost-effective strategy is to build more sustainably to retain, store, clean and recycle on-site stormwater, decentralizing water-related infrastructure. Vegetated roofs and swales, pervious paving with permeable substrates and cisterns greatly reduce the volume of stormwater running off a site into central sewer networks.

But a fundamental question was always lurking in the room like the proverbial 800-pound gorilla. Why have the American public and government been unwilling to tackle infrastructure problems and make critical infrastructure investments?

Whether you are a homeowner living in D.C., Virginia or Maryland, you probably can provide several answers to this question, as did the journalists.

●Infrastructure is mostly invisible — the forum title was “Urban Infrastructure: Hiding in Plain Sight” — and is not the sexiest topic for political discourse or for journalism.

●Most homeowners and public officials subscribe to the “if it ain’t broke, don’t fix it” philosophy, especially when fixing entails large sums of money. Thus, Americans tend to pay attention, act and open their wallets only after a serious crisis has arisen or a catastrophe has occurred.

●Expenditures for necessary infrastructure maintenance, repair, replacement or new construction requires capital investments far beyond the fiscal capacity of today’s local, state and federal budgets. Infrastructure funding must compete with funding for countless other expenses, typically assigned higher priority.

●In reality, adequate public infrastructure investments can be made only if taxes and user fees are substantially increased, for which little political will or taxpayer support currently exist.

Clearly, ramping up infrastructure priority and spending will continue to be an uphill political and financial battle, one I think about these days every time I hit a pothole.

Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland. His cartoon may be seen at www.washingtonpost.com/realestate .