From cities in the sky to robot butlers, futuristic visions fill the history of PopSci. In the Are we there yet? column we check in on progress towards our most ambitious promises. Read more from the series here.

In just the past year, countries around the world have continued rolling out high-speed trains. France revealed its next generation high-speed train, TGV M, which is larger, more carbon efficient, and travels up to 220 mph. Italy unveiled direct high-speed rail links from Rome’s airport to Naples and Florence. China opened 140 new miles of high-speed rail, while also showcasing a line dedicated for the 2022 Winter Olympics. And Japan, which debuted the bullet train in 1964, will be opening a new 41-mile high-speed rail line from Takeo Onsen to Nagasaki. But here in the US, home to more than 150,000 miles of railroad tracks—the most in the world—it’s been high-speed rail crickets. 

To be fair, Amtrak did announce that its new top speed for its Acela train on northeast routes, or Northeast Corridor (NEC), is 150 mph on a 16-mile track segment in New Jersey—still shy of other high-speed rail like China’s recently upgraded Beijing-Wuhan line that zips between 190 to 220 mph. What’s more, California, Texas, Nevada, and the Northeast, all have rapid rail projects that have been sputtering along for years.

But three decades ago, in June 1992, Popular Science published a story that predicted high-speed rail would soon launch in major US regions, with more to follow. “Florida recently approved a plan to build a magnetically levitated, or maglev, train system that would begin operating in 1996,” wrote senior contributing editor Chris O’Malley, further adding that high-speed rail was going to be dashing through Texas as soon as 1998. Unfortunately, neither project came to fruition. Still, PopSci was not alone in covering the hope for high-speed rail in the US. In August 1992, Scientific American also ran a feature on the promise of maglev trains. In March 1990, The New York Times reported efforts to build a high-speed rail system linking Ohio cities, a project based on Florida’s plans for an anticipated 325-mile high-speed rail. But none of the high-speed rail plans or projects underway three decades ago succeeded. Zero. Despite the allure of quietly humming past changing scenery at 200 mph or more on an electrically and sustainably propelled ride, without having to navigate airport traffic and security lines, the US is not poised to install high-speed rail anytime soon, anywhere. 

“The US is really a very auto-centric country,” says Ian Rainey, a senior vice president at Northeast Maglev, a privately held company associated with Central Japan Railway. “When a lot of countries were investing in high speed rail in the 1950s, 60s, and 70s, the United States was building out the interstate highway system.” He adds that once such highway systems are built out, “you want to keep investing in them, keep them in good shape. And that takes money.” Money that could have been—and could still be—spent on rapid rails.

When it comes to achieving high transit speeds on terra firma, there are three main contenders, each requiring unique technology and engineering: high-speed rail (HSR), maglev, and hyperloop. If we were to place them on a rapid-rail reality meter, HSR would score a 10 out of 10 (widely available commercially, mature tech); maglev would earn a 5 (limited commercially, extensive prototypes); and, hyperloop would rank at 2, (early prototypes that are a long ways away from commercial deployment). 

Japan was the first to debut HSR in 1964, when it opened the Shinkansen (meaning new trunk line, also well known as a bullet train), between Tokyo and Osaka just in time for the ’64 Olympics. HSR’s advantage over other contenders is that it uses standard gauge tracks, although the tracks must be flat (low gradients) and straight to achieve its top speeds of 220 mph; any curves must be gentle. The trains (known as rolling stock) are also more streamlined than conventional trains, have more powerful engines, and some are designed to tilt as much 8 degrees to hug the track on turns. HSR trains can theoretically share tracks with regular trains, as long as route design and signaling systems support the speed disparities. Amtrak has been making such upgrades for decades to its NEC main line to accommodate its Acela trains. 

[Related: This super-fast jet train would tap into a whole new field of physics]

The problem with upgrading old tracks, regardless of location, is that they weren’t designed for high speed. “The alignment was laid out a long, long time ago,” Rainey notes. “So now you’ve got a fairly curved track, with a lot of residential and commercial area developed around it in the past 100 to 150 years. And so it’s very difficult to straighten it out.” That’s why Amtrak’s trains can’t achieve higher speeds, and probably never will on the NEC main line, which runs mostly above ground through densely populated regions.

Where HSR trains rarely travel faster than 220 mph, magnetic levitation, or maglev, has potential to achieve travel speeds greater than 300 mph, while being quieter and more energy efficient than HSR. Magnetic levitation transportation was first proposed by rocket-engine inventor Robert Goddard in a 1909 issue of Scientific American. Goddard’s early concept also incorporated features that can be found in today’s hyperloop designs, such as partial-vacuum tunnels to reduce drag. At the time, electromagnetic transportation possibilities were also being explored by other inventors, although none would even be prototyped until the 1970s. Maglev trains run on concrete guideways lined with electromagnets that repel the magnetized cars, elevating them millimeters to inches above the track (varies depending on the levitation technique). The motor, known as a linear induction motor, is not in the train, but on the guideway, using alternating magnetic poles like a conveyor belt to propel the train forward and slow it down (you can make your own mini model levitating train at home). Because maglev trains require entirely new guideways, cars, and power specifications, they must be built from scratch. Despite their decades-long allure, implementation costs can be prohibitive relative to HSR. Today there are only six operational maglev trains—three in China, two in South Korea, and one in Japan. Only one qualifies as high speed, China’s Shanghai maglev, which runs for 18.6 miles from a subway station to the airport, and reaches 268 mph during the 7-minute trip. 

a popular science magazine cover with an illustration of a high speed rail train. the title reads '310-mph maglev trains for U.S. cities rapid rails'
The June 1992 cover of Popular Science. Popular Science

As rapid rails reach for higher speed and efficiency, however, maglev may finally find a wider role—and offer a more appealing venture. Central Japan Railway has been perfecting a new kind of maglev powered by superconduction, which is capable of achieving speeds greater than 300 mph, well above HSR limits. Superconducting maglev uses a wire, or coil, chilled to -452°F to reduce electrical resistance and generate a magnetic force that is more powerful and requires less energy than a conventional electromagnet. This would allow for higher propulsion speeds. In Japan, plans are well underway to install a new superconducting maglev train alongside the renowned Shinkansen bullet train.

In the US, Rainey’s company, Northeast Maglev, has been collaborating with Central Japan Railway to build a superconducting maglev train between Washington, DC and New York City. On Amtrak, that trip currently takes 2 hours 35 minutes nonstop, but on a superconducting maglev train, passengers would arrive at their destination in about an hour. Since Amtrak’s mainline can’t accommodate very high speeds, Northeast Maglev sees an opportunity for a new 300 mph train running between the Northeast’s most populous cities. To avoid right-of-way issues, most of the new train line will run underground through deep tunnels. But maglev trains require large tunnels—even larger than the century-old, low-slung New York subway tunnels—having to accommodate multiple guideways and a high-speed form factor (straight and level). That’s where hyperloop tunnels may have an edge.

Hyperloop transportation is the most futuristic rapid-rail contender. Although Elon Musk is often credited for hyperloop designs with his 2013 Hyperloop Alpha whitepaper, the primary concept has been around over the past century. As early as 1909, Goddard developed a hyperloop design—outlining the core components of airtight tubes and cars propelled on a cushion that is either air or magnetic. Later in August 1961, PopSci published a story featuring cars traveling through aeroduct pipes on cushions of air. After Musk’s whitepaper, startups and investors poured money and interest into hyperloop designs, resulting in a trial of Virgin Hyperloop in November 2020 outside of Las Vegas, Nevada. But despite a resurgence, there are only a handful of prototypes underway around the world. 

[Related: The first hyperloop passengers just took a short but important ride]

“I think the [Loop] concept is intriguing and potentially makes a lot of sense,” Rainey says. But he doesn’t see it competing with maglev designs because, while high speed, hyperloops are geared toward individuals driving their own cars versus mass transit. That’s why their tunnels can be smaller and faster to bore.

For a country with the largest railway network in the world, it may seem counterintuitive that the US has been unable to debut a single high-speed rail system. That said, Amtrak markets its Acela train as high speed, which the company can claim because there is no industry standard for a train to be considered “high-speed rail.” But with a 150 mph top speed achievable only for short distances, and an overall 68 mph average, it’s really not much faster than a typical commuter train with short high-speed segments. By contrast, its European and Asian counterparts regularly top more than 200 mph with average speeds well over 100 mph. Despite its world-leading size, the US rail system moves mostly freight, not people. Less than 15 percent of US rail lines are used by passenger trains. When viewed through the lens of passenger-miles traveled by train, as a country the US does not even make the world’s top ten. One statistic kept by the US Bureau of Transportation explains why: In 2019, the US logged 3.75 trillion passenger-miles driving cars and motorcycles (add another 2 trillion for trucks), but commuted only 12.7 billion passenger-miles riding trains. On a US passenger-mile pie chart, train travel would be about the width of a hair.

As Rainey points out, the US has been a car-centric culture for more than a century. Not even Elon Musk, with his hyperloop hoopla, is likely to change high-speed rail’s destiny in the near future. But that doesn’t mean there’s no place in the US for rapid rails. When they do eventually arrive—and they’re coming, on the slow train—their scope will likely be limited to specific cities and travel routes, like the projects underway in California and Texas, or in highly congested regions like the Northeast. That’s because the high-speed rail experience and economics work best when a few key travel conditions are met: First, when trains can move city to city making few stops along the way and reducing travel time, meaning taking travelers quickly between cities that are dense urban centers with limited suburban sprawl; second, when there’s enough space for new or modified rail infrastructure, including underground; and, third, when the major competition—cars and planes—can no longer expand impeded by lack of sufficient roadway and airport capacity. But even if certain routes between select cities (like in-progress projects between Los Angeles and San Francisco in California) find popular passenger demand, it’s unclear if high-speed rail would catch on to the extent it has in Japan, Europe, and China. In the car-dominated, airport-saturated US, only a handful of places can check all the boxes. 

“If you can get that sweet spot of big populations that are 100 to 300 miles apart from each other,” Rainey says, “I think you’ve got a winner for high-speed rail.” Citing the billions of dollars allocated for high-speed rail in the Infrastructure and Investment Jobs Act passed by Congress in 2021, he adds that the US may be at a tipping point where some of the projects underway will finally come to fruition. As for Northeast Maglev, Rainey says, “maybe by early 2030s, we’ll able to buy a ticket from DC to Baltimore.”