We don’t know yet what caused Tuesday night’s train derailment in Philadelphia. We do know that, for decades now, the United States has been allowing its public infrastructure to decay. Photograph by Joseph Kaczmarek / AP

This post has been updated to reflect new information about the crash.

Last week, I took Amtrak’s Northeast Regional service from Washington, D.C., to New York. It’s a lot cheaper than the Acela Express, and when it’s on schedule it does the trip in under three and a half hours. Unfortunately, it runs late about thirty per cent of the time, and this was one of those occasions. As we slowed to a crawl somewhere in Delaware, I happened to be reading the China Daily newspaper, which I had picked up at Union Station. It included a color spread on a new superhighway that the Chinese have carved through the mountains in Sichuan province. With great stretches of roadway raised on high concrete stilts, and long tunnels disappearing into the side of hills, it looked amazing.

I was tempted to compose a tweet about contrasting approaches to investing in transportation infrastructure, but I didn’t bother. At this stage, it has become something of a cliché to compare Amtrak to Japanese bullet trains and the Eurostar, or J.F.K. to airports in Hong Kong and Singapore. Last year, when Vice-President Joe Biden said that La Guardia looked like it was in the “third world,” some New Yorkers pretended to be offended, Mayor de Blasio and Governor Cuomo among them. But everyone was aware that Biden was only speaking the truth.

We don’t know yet what caused Tuesday night’s train derailment in Philadelphia, which killed at least seven people and injured scores more. On Wednesday, the National Transportation Safety Board said that the train was travelling at more than a hundred miles an hour, on a sharp turn where the speed limit was just fifty miles an hour. But even if human error was responsible for what happened, the crash also highlights the fact that some stretches of the track that Amtrak uses are unsuitable for high-speed travel, and they are also not equipped with the modern technology necessary to enable automatic override systems, which can slow down speeding trains. (According to Reuters and the Times, the train that derailed did have an automatic safety system installed, but it didn't work on the track where the derailment took place.)

One thing we do know for sure is that, for decades now, the United States has been allowing its public infrastructure to decay. In 2013, the American Society of Civil Engineers issued a report saying that it would take roughly $3.6 trillion worth of repairs and retrofitting merely to return the nation’s roads, railways, and airports to a safe and durable state. For example, about one in nine bridges in the U.S. were structurally deficient, according to the Federal Highway Administration.

And that’s just transportation infrastructure. Many of America’s schools, sewage systems, and parks could do with an upgrade, too. A couple of years ago, a survey by the World Economic Forum ranked the United States twenty-fifth globally in overall quality of infrastructure, behind such nations as Spain, Oman, and South Korea. That’s hardly surprising. In my neighborhood in Brooklyn, where townhouses are now selling for millions of dollars, the sewers, which were built more than a century ago, sometimes back up after a heavy rainstorm.

It’s no mystery why much of our public infrastructure is overloaded and crumbling. America is a growing country, and investment in infrastructure has failed to keep up with expanding needs. According to the Congressional Budget Office, in the nineteen-fifties and sixties we spent close to five per cent of G.D.P. on new transport and water projects, and on maintaining existing systems. European nations still spend about that much today, while China and other rapidly developing Asian countries spend close to twice as much. In the United States, however, spending on infrastructure is only about half of what it used to be, relative to G.D.P.

This situation is a direct product of politics. As entitlement spending has grown and pressure to cut the federal budget has increased, infrastructure spending has been tightened. The squeeze was relaxed for a few years as a result of President Obama’s stimulus program, but it’s now back in effect. Take the federal Highway Trust Fund, which historically has paid for about a third of public-transportation projects around the country. It is almost always operating in the red, largely because the gasoline tax that finances the fund hasn’t been raised since 1993. Over the next ten years, it is facing a financial shortfall of about a hundred and seventy billion dollars, according to the Congressional Budget Office, but Republicans in Congress are blocking efforts to raise more revenues.

Amtrak, too, is perennially short of funds. As one of the largest and costliest public-transportation systems in the country, it has long been a target of conservative, anti-government types. This despite the fact that is increasingly popular with riders. Since 2000, the number of passengers using Amtrak each year has risen by almost half, to more than thirty million, and new, faster services, such as the Acela, have proven to be big successes. Close to eleven million people travelled on Amtrak’s Northeast Corridor routes alone last year. To be sure, the company still loses money, but that’s true of virtually all public-transportation systems the world over. As most countries recognize, accounting profits (or losses) don’t take account of the broader social and economic benefits that such systems provide.

If Amtrak had the resources to invest in new equipment—particularly newer, straighter tracks—it could be a lot more popular and successful, as well as safer. The company estimates that trips between New York and Washington, and from New York to Boston, could be reduced to about an hour and a half. And with upgrades south and west of the Northeast Corridor, there is no reason why Florida and Chicago couldn’t be within a morning or afternoon’s train ride from Penn Station.

Instead of trying to make this vision a reality, Congress continues to chisel away at Amtrak, and public infrastructure generally. On Wednesday, according to a report at Politico, a panel of the House Appropriations Committee was considering a funding bill that “would slash Amtrak’s funding to $1.13 billion, less than the roughly $1.4 billion it typically receives.” President Obama, by contrast, has proposed a transportation bill that would dedicate almost five hundred billion dollars, over six years, to repairing existing infrastructure projects and building new ones. So far, the bill hasn’t gotten anywhere.

It’s possible that the White House and Republican leaders on Capitol Hill will still reach some sort of compromise, particularly over the Highway Trust Fund, the legal authority for which is about to expire. But there is virtually no prospect of the United States making the investments it needs to catch up with other western countries, such as Germany, or even with China, which, by 2020, will have laid almost twenty thousand miles of high-speed rail track.

About the best we can hope for is that, in five years’ time, the Acela and the Northeast Regional will still be running up and down the East Coast, slowing down to take bends in the track and to cross the Susquehanna River on a steel bridge that was built in 1905. In 2013, then transportation secretary Ray LaHood announced a two-billion-dollar initiative to improve train service on the Northeast Corridor; one of the proposals he put forward was replacing the bridge over the Susquehanna. I will believe we’re making progress when I am riding over its successor.