When the Scottish sinologist James Legge set out from Shanghai to Beijing in the spring of 1873, the journey took him two weeks. First, he travelled by boat to Tianjin, and then by mule cart to the Chinese capital. Today, the same 1,200-kilometre trip takes just over four hours by high-speed rail. Flying between the two cities takes two hours and 20 minutes.

 

Humans have never before travelled as quickly or easily as they do today. But that convenience has come at a cost: transportation accounts for 20 percent of global carbon emissions, and the rate at which transport is pumping carbon dioxide into the atmosphere has increased faster than any other source over the past three decades. That’s especially true for air travel, whose emissions have grown faster than rail or road. That raises a question: is it possible to travel at high speeds without killing the planet? And if so, how?

 

The Channel Tunnel Rail Link, also known as High Speed 1, a 109.9km high-speed railway leading to the Channel Tunnel. (Photo courtesy of Arup)

 

The future of high-speed transportation has long been the subject of fantasy. Science fiction promised flying cars and teleportation, but the reality has been more mundane. It’s telling that when renowned sci-fi writer H.G. Wells penned Anticipation, a book of nonfiction essays about the future, first published in 1901, his chapter on transportation predicted the rise of… motorways. It turned out to be spot-on, but it was certainly the least compelling chapter in the volume.

 

Today, there is a new crop of ideas that straddle the line between the realistic and the fantastical. NASA is working with Lockheed Martin to develop a quiet supersonic jet that resolves one of the biggest problems with the Concorde, which was limited to trans-Atlantic flights because of the ear-popping sonic boom it created when it exceeded 1,236 kilometres per hour. Elon Musk has promised Earth-to-Earth rocket travel through his company SpaceX, which could reduce trips between any two points on the planet to just 30 minutes. But experts have dismissed this as inherently unaffordable, impractical – and dangerous. “The acceleration and the G-forces for both the launch and the reentry would kill people,” space operations expert Brian Weeden told The Verge in 2017. And neither rockets nor quiet supersonic jets resolve the issue of carbon emissions.

 

Another one of Musk’s projects is the hyperloop, which would send capsules full of people through sealed low-pressure tubes, either in tunnels or on an elevated guideway above ground. The pods would gradually accelerate using linear electric motors before gliding along their track on air bearings, reaching a theoretical top speed of 1,223 kilometres per hour. Researchers around the world have been testing the concept, which is technically feasible: a trial run at the Technical University of Munich reached a speed of 463 kilometres per hour. But running an experiment at a university is quite a different thing than actually using the technology to transport real human beings.

 

There’s also the question of cost. “Hyperloop would have to be relatively inexpensive to become competitive with existing high-speed rail,” says Bent Flyvbjerg, an economic geographer, megaproject expert and professor at Oxford University and the IT University of Copenhagen.

 

Hyperloop tests in Germany in a sealed low-pressure tube. (Photo courtesy of Technical University of Munich)

 

It turns out the future of high-speed transportation is already here. And it has been for a very long time. Japan opened its first high-speed railway between Tokyo and Osaka, the Tōkaidō Shinkansen, in 1959. Today, it is still the fastest way to travel between the two cities, with 285-kilometre-per-hour trains completing the journey in 2.5 hours. New E956 Series trains being tested are capable of reaching 360 kilometres per hour in regular passenger service.

 

Flying between the two cities takes less than 1.5 hours, but security checks, waiting time and travel to and from airports makes the total journey time longer than the so-called bullet train. And the shinkansen is the least carbon-intensive form of travel between Tokyo and Osaka, adding up to 4.2 kilograms of carbon emissions per passenger, about one-third less than driving and 12 times less than flying. “High-speed rail is a long-term investment in a net zero future,” says Andrew Went, Global High Speed Rail Leader at engineering firm Arup, which has been involved in a number of high-speed rail projects around the world.

 

Perhaps the biggest advantage of high-speed rail is replicability. “The Chinese have it down, they can just churn it out – mile after mile, hundreds of miles after hundreds of miles,” says Flyvbjerg. “And that's what you want to get – that scaling. Like with any product, it doesn't become really efficient and economical until you can scale it up like the Chinese now do. It makes it less risky.”

 

Over the past 20 years, China has linked nearly the entire country together with a 42,000-kilometre web of high-speed railways. It’s what a number of other countries have already done — notably France and Japan — but on an enormous scale. And it is immensely popular. In 2021, despite the Covid-19 pandemic, China’s high-speed rail network carried 1.9 billion passengers, an increase of 23.1 percent over the previous year. Hong Kong’s branch of the national high-speed rail network has already served 17 million passengers this year, surpassing pre-pandemic ridership.

 

And yet high-speed rail has been greeted by scepticism in many parts of the world, notably the United States. A high-speed railway currently under construction between Los Angeles and San Francisco has been plagued by massive cost overruns and delays, feeding a chorus of critics who dismiss high-speed rail as a “money sink,” in the words of Randal O’Toole, public policy analyst at the libertarian Cato Institute.

 

High-speed shinkansen train waiting to depart from Tokyo Station. (Image via Wikimedia)

 

Experts generally agree that high-speed rail can compete with air travel within distances of less than 1,500 kilometres; this is one reason why France has banned short-haul flights that can be better served by rail. But that only works if the rail actually gets built. And that’s the biggest stumbling block, according to Flyvberg, who recently co-authored a book on megaprojects with journalist Dan Gardner, How Big Things Get Done. Flyvbjerg has proposed what he calls the Iron Law of Megaprojects, which is that they are invariably “over time, over budget, under benefits, over and over again.” His global analysis of such projects revealed that just 8.5 percent of them are actually delivered on time and on budget.

 

To avoid such a fate, he says megaprojects need to focus on planning to avoid expensive improvisations, and to make use of as much standardisation and modularity as possible. That’s how France and China built such robust high-speed rail networks, and the failure to take such an approach is why California’s high-speed railway has jumped in cost from US$40 billion to a mind-boggling $128 billion. Work began in 2008 but the first phase of the project, which will connect two small cities in California’s Central Valley, won’t open until 2030.

 

Flyvbjerg blames politicians for the mess: not just wavering and flip-flopping over budgets and routing, but an insistence that the project’s design, materials and construction be American – even though the US has no previous experience in building high-speed rail. “It's not a good idea to hire somebody to do a project who has not tried to do that project before,” says Flyvbjerg. “Which seems like a no-brainer, if you think about it, but nevertheless, it happens again and again for political reasons.”

 

If best design practices are followed, however, there’s a bright future for high-speed rail. Andrew Went, who worked on the so-called HS1 railway that provided high-speed service to southeast England, including a portion used by Eurostar to connect London with Paris and Brussels, offers a few key pieces of advice. First, he says, “plan for the full railway lifecycle, [because] poorly designed systems or badly planned maintenance can have severe long-term consequences.” Make sure the high-speed railway is integrated into existing systems – “trains, tracks, signalling, communications, power, infrastructure, people, and processes,” he notes.

 

It’s also crucial to “design the route and stations to maximise the economic, social and environmental benefits for local communities,” he says. “High speed rail lines tend to have fewer stations than suburban rail lines or metros, but these stations can have significant benefits for the local area, as well as for onward connectivity.” With this in mind, it’s important to conceive a high-speed railway as part of a transport network, rather than as a standalone piece of infrastructure.

 

Finally, mind the carbon. High-speed rail is electric and therefore emission-free, although its true level of carbon emissions depends on whether its power source is renewable or not. But there is also a certain amount of embedded carbon in the steel and concrete used to build the railway, especially considering that high-speed rail requires a relatively straight route and no level crossings, which often requires the construction of concrete-heavy viaducts. Went says any new railway needs to have a big-picture plan to minimise its environmental impact wherever possible.

 

New technology is making this all easier, particularly agent-based modelling and digital twins that use machine learning and artificial intelligence to test different scenarios – a change in policy or user behaviour, for instance. But there’s also a need for real-world community engagement: “Start with a clear dialogue and aim to develop any plan as a collaborative programme as these schemes can take decades to devise, deliver and operate,” says Went.

 

Shanghai's maglev line, which connects the Pudong Airport with the city centre. (Image via Wikimedia)

 

And don’t forget about people who may be impacted by the high-speed railway without receiving any direct benefit. “What is returned to them? Is it employment, improved societal benefits?” asks Went. “Keeping them informed and involved in key aspects of the delivery programme is crucial and critical to its success.

 

High-speed rail certainly doesn’t have a monopoly on the future of high-speed travel. Maglev is another type of high-speed rail that uses magnets to levitate a train above its guideway, which allows it to achieve extremely high speeds. But high costs have prevented its development and there are only six maglev lines in operation today. One of them is the Shanghai Transrapid, the world’s fastest passenger rail service, which was built in collaboration with Germany in 2001. Despite moving passengers at a brisk 431 kilometres per hour, its success has been limited: instead of extending the Transrapid, which acts as a shuttle between Pudong Airport and the city centre, China opted to build more conventional high-speed rail.

 

For its part, Hyperloop is possible in theory, although it may be decades before it is actually realised. The aviation industry is experimenting with hybrid and electric aircraft, even if experts warn it will take major advances in battery technology before a typical passenger jet can be emission-free. And Flyvbjerg says self-driving EVs could be an unexpectedly cost-effective way to travel long distances at relatively high speeds: an electric autobahn, in other words.

 

These are all ways that we may one day get around without harming the environment. But for now, the future is here: high-speed rail offers a fast, low-carbon way to get between cities. If James Legge was making his journey to Beijing today, he wouldn’t need to take a ship, and he certainly wouldn’t need a mule. He’d just need to hop on a train.

 

 

Writer: Christopher DeWolf

 

This column is produced in partnership with Zolima CityMag, an online magazine that explores Hong Kong’s arts, design, history and culture.