What if there were a technology that could help to reduce greenhouse-gas emissions, air pollution and environmental degradation, while improving health, reducing social inequality and boosting economic growth? There is, and this month it turns 200. The opening of the Stockton and Darlington Railway in northeast England on 27 September 1825 is generally considered to be the birth of the modern railway — an event that set in motion a revolution in human mobility and social organization.
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Initially, the railways enjoyed breakneck expansion, but since the mid-twentieth century, railway development in most countries has hit the buffers, and been overtaken by growth in road and air travel. A study by the Paris-based International Transport Forum (ITF) of 51 mainly high- income countries found that rail’s share of freight transport had fallen from 38% in 1980 to 24% in 2017 (see go.nature.com/3vpckhd). In the European Union in 2022, just 8.4% of passenger kilometres were travelled by rail, compared with 9% by air and 73% by car.
Despite prominent investments in high-speed rail in Japan, China and parts of Europe, the overall length of networks in many countries has declined as conventional lines deemed unprofitable have been cut. Meanwhile, rail transport is a low priority in many low- and middle-income countries, where networks are sparse or non-existent. The entire African continent, for example, has just 87,000 kilometres of rail. By contrast, India has at least 65,000 kilometres, and a land surface area just one-tenth of the size.
It’s time to turn the tables, and acknowledge the vast benefits of railways as a cornerstone of a sustainable transport system that can support human development and economic growth. Research from across disciplines can inform policy in preparation for a much-needed renaissance, as railways travel into their third century.
According to the International Energy Agency, transport currently accounts for around one-quarter of global carbon dioxide emissions. Between 1990 and 2022, those emissions grew by 1.7% a year — an increase greater than that of any sector besides industry — as more people in more parts of the world became more mobile. Over 90% of the energy used to power transport comes from fossil fuels.
Those figures alone justify a renewed focus on rail transport. Per passenger kilometre, it produces one-fifth of the emissions of car transport, and less than one-quarter of those of flying. Direct emissions can be cut to zero if trains are powered by fully renewable electricity.
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Rail transport also contributes little in the way of air-fouling particulate emissions, which are a health hazard. This is particularly important in a rapidly urbanizing world. Better rail-based mass-transit options could help to reduce urban sprawl, as well as the land needed for roads, car parks and other car-related infrastructure. Less-congested cities with fewer motor vehicles are more liveable places where people are more inclined to walk and cycle, reaping the health benefits of these activities. They are also more inclusive, particularly for younger and older people who are less likely to own a vehicle. As both urbanization and average population density grow, research shows that the economic benefits of investment in rail outstrip those of investment in roads1.
But it is not just cities. The United Kingdom will be celebrating its role in birthing the railways later this month, but the country also offers an example of the effects disinvestment in railways can have. A 2024 study2 examined a sustained programme of cuts made to the nation’s railway network from the 1950s to the 1980s. It found that the predominantly rural areas most affected by the cuts saw population declines, job losses and drops in the number of skilled workers, relative to areas that were unaffected.
One way research can help to get things back on track is by broadening the criteria governments use to assess railway investment, says Christian Wolmar, an independent transport consultant and author based in London. All too often, these are based on narrow metrics of profitability or ‘time saved’ by potential users, with insufficient consideration of the wider social and environmental impacts. Economists, other social scientists and sustainability researchers can all contribute to developing more-robust assessments of these indirect benefits.
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Such initiatives can feed into broader regulatory and policy frameworks. Only one-third of countries have fully incorporated the transport sector into their ‘nationally determined contributions’ — their ongoing commitments to reduce greenhouse-gas emissions under the 2015 Paris climate agreement — according to an ITF tracker (see go.nature.com/4nxdiju). To meet net-zero targets, emissions from transport need to decline by 3% a year from now on.
Research can also illuminate the winners and losers created by investment decisions. China, for example, is set to continue the breakneck expansion of its high-speed rail, aiming to reach 60,000 kilometres by 2030. But scholars are debating the wisdom of the speed and scale of this expansion, with uncertainty remaining about how widely the economic benefits of high-speed links are distributed3.
At its zenith, immediately before the First World War, the US rail network extended to more than 400,000 kilometres — greater than the distance from Earth to the Moon. Today, it covers little more than half of that. The extent of this decline underscores the need to turn around the neglect of a technology that has not only changed the world, but could also save the planet.