Rail Transportation: Creating Opportunities for Energy & Environment

The future of rail will be determined by how it responds to both rising transport demand and rising pressure from competing transport modes.

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Rail is among the most efficient and lowest emitting modes of transport. With a strong reliance on electricity, it is also the most energy diverse. Rail networks carry 8% of the world’s motorised passenger movements and 7% of freight transport but account for only 2% of energy use in the transport sector. Rail services consume less than 0.6 million barrels per day (mb/d) of oil (about 0.6% of global oil use) and around 290 terawatt-hours (TWh) of electricity (more than 1% of global electricity use).

They are responsible for about 0.3% of direct CO2 emissions from fossil fuel combustion and the same share (0.3%) of energy-related emissions of fine particulate matter (PM2.5). The high efficiency of train operations means that rail saves more oil than it consumes and more emissions than it generates. If all services currently performed by railways were carried by road vehicles, such as cars and trucks, then the world’s transport-related oil consumption would be 8 mb/d (15%) higher and transport-related greenhouse gas (GHG) emissions would increase by 1.2 gigatonnes (Gt) CO2-equivalent (CO2-eq) on a well-to-wheel basis.

Rail has a long-standing position as one of the pillars of passenger mobility and freight transport. Today, conventional rail provides nearly one-sixth of the world’s long-distance passenger travel around and between cities. High-speed rail provides a high-quality substitute for short-distance intracontinental flights. In cities, metros and light rail offer reliable, affordable and fast alternatives to road travel, reducing congestion and carbon dioxide (CO2) emissions and local pollution. Freight rail enables high capacity goods movements over very long distances, allowing access to trade for resources that otherwise would likely be stranded and facilitating the operation of major industrial clusters.

Classification of rail transport services

Railways make a significant contribution in providing various types of services, referred to as passenger or freight rail. Categorising sub-sets of passenger and freight rail is a challenging undertaking. For passenger rail, this has been addressed by considering key characteristics, such as speed and location, but always within the limitations of the data available. The categories and terminology employed are:

  • Conventional rail, covering medium- to long-distance train journeys with a maximum speed under 250 kilometres per hour and suburban train journeys connecting urban centres with surrounding areas.
  • High-speed rail is defined as rail services over long distances between stations, operating at a maximum speed above 250 kilometres per hour.
  • Metro rail, refers to high-frequency services within cities, designed for high capacity transport (standing passengers and many wide doors for rapid boarding and exit), which are fully separated from other traffic and are often developed as an underground and/or elevated network.
  • Light rail, refers to tramways and other urban transport systems, most often at street level and offering lower capacity and speed compared with metro rail.

Metro rail and light rail are often aggregated as urban rail (that is rail within cities and the immediately surrounding area), while conventional and high-speed railway systems are together referred to as non-urban rail. In the discussion of rail infrastructure, the term conventional rail lines (or tracks) designates the infrastructure used by both passenger conventional rail and freight rail.

In addition to metro systems and light rail, urban areas are also serviced by commuter, or suburban, rail systems, connecting the city centres with suburban areas. While commuter rail services constitute a significant proportion of passenger transport activity, they are not very often included in separate analyses because of data unavailability or unreliability. This is a significant limitation for some aspects of the analysis since commuter rail is an important part of urban mobility, but unfortunately, it cannot be fully isolated. Classification issues are simpler for freight rail, which is defined as the transport of goods on dedicated freight trains.

Some Major Facts about rail transport

  • In 2016, passengers travelled over 4 trillion kilometres by rail, around 8% of total transport passenger-kilometres. Rail travel is concentrated in a few regions: China, the European Union, India, Japan and Russia, which together make up about 90% of global passenger rail activity. Despite the rapid expansion of metro and high-speed rail systems over the past decade, the share of rail in global motorised passenger transport has remained roughly constant.
  • Today, around 600 billion passenger-kilometres are travelled by high-speed rail every year compared with 3 100 billion by conventional rail. Two-out-of-three high-speed rail tracks are in China, which starting from virtually zero only a decade ago has built over 41 000 kilometres of high-speed rail tracks. The speed and size of this achievement place it among the largest infrastructure projects of recent years.
  • Nearly 200 cities worldwide have metro systems. The combined length of the metro tracks exceeds 32 000 kilometres. Light rail systems add 21 000 kilometres of track length, across more than 220 cities. The pace of extension of China’s metro network since 1990 has outstripped the global average, pushing the country’s share of global metro networks from less than 10% in 1990 to more than 28% in 2017. Since urban rail is typically electric, travel by metro and light rail systems gives rise to none of the tailpipe emissions associated with road transport and can achieve zero-emissions mobility overall.
  • About 7% of global freight transport activity, as measured in tonne-kilometres, goes by rail. Growth was very rapid at the turn of the century but slackened and levelled off thereafter. In contrast to Europe, Japan and Korea, where rail networks mostly serve passengers, rail networks in North America overwhelmingly cater to freight transport. In Russia, more than half of freight activity takes place on rail. Australia, Brazil, Canada, India and South Africa also carry substantial volumes of goods by rail.
  • Rail transport today accounts for close to 2% of final transport energy use, a modest share compared with rail’s share of transport activity. Three-quarters of passenger rail transport and almost half of all freight rail is electric, using around 290 TWh of electricity every year (25 Mtoe). Diesel-powered trains account for the remainder of final energy use (0.6 mb/d, or 28 Mtoe a year). Electric and diesel trains together give rise to around 3% of all well-to-wheel greenhouse gas emissions from the transport sector.
  • Although rail is an energy consumer, it also makes an important contribution to containing energy demand. If all passenger and freight services currently carried by rail switched to road vehicles, such as cars and trucks, global oil demand from transport today would be 16% higher (8 mb/d). The contribution rail makes to containing GHG emissions is as significant as its energy savings. If all current passenger and freight traffic by rail shifted to road vehicles, global GHG emissions would increase by 1.2 Gt of CO2-eq, or 12% more than total emissions from transport today.
  • Investment in rail infrastructure is expensive. In order for a rail construction project to pay off, high passenger or freight throughput is necessary. If this condition is met, shifting large quantities of transport away from cars, trucks and planes delivers very important societal and environmental benefits, which may not be fully captured in conventional commercial pricing.

Most rail networks today are located in India, China, Japan, Europe, North America and the Russian Federation, while metro and light rail networks operate in most of the world’s major cities. About 90% of global passenger movements on conventional rail take place in these countries and regions, with India leading at 39%, followed by China (27%), Japan (11%) and the European Union (9%). Globally, about three-quarters of conventional passenger rail activity use electricity, and the remaining quarter relies on diesel. Significant investments have been made in high-speed rail and metros, most notably in China, which has overtaken all other countries in terms of network length of both types within a single decade.

Today China accounts for about two-thirds of high-speed rail activity, having overtaken both Japan (17%) and the European Union (12%). The regional distribution of urban rail activity is more even; China, European Union and Japan each have around one-fifth of urban passenger rail activity. Both high-speed and urban rail are entirely powered by electricity. Freight movements are concentrated in China and the United States, each of which accounts for about one-quarter of global rail freight activity, and Russia, which accounts for one-fifth. Despite the fact that electrification of freight rail faces greater challenges than other rail types, half of the global freight movements rely on electricity.

Future of Rail – Opportunities for Energy & Environment  

The future of rail will be determined by how it responds to both rising transport demand and rising pressure from competing transport modes. Rising incomes and populations in developing and emerging economies lead to strong demand for mobility, but social considerations and the need for speed and flexibility tend to favour car ownership and air travel. Rising incomes also drive demand growth in freight, where higher incomes, together with digital technologies, have sharply increased demand for rapid delivery of higher value and lighter goods. The rail sector has important advantages to exploit in competing for business, but this will require additional strategic investments in rail infrastructure, further efforts to improve its commercial competitiveness and technological innovation.

In the Base Scenario, annual investment in rail infrastructure is expected to increase to USD 315 billion globally by 2050, on the basis of projects currently in various stages of construction and planning. In this scenario, which assumes no significant new emphasis on rail in policy making, the pace of infrastructure build is fastest in urban rail. The length of metro lines under construction or slated for construction over the coming five years is twice the length of those built over any five-year period between 1970 and 2015. The result is unprecedented growth in passenger movements on urban rail; global activity in 2050 is 2.7 times higher than current levels. Growth is strongest in India and Southeast Asia, which witnesses more than a sevenfold growth in passenger movements on the urban rail, albeit from a low baseline. In the three countries with the highest urban rail activity today, activity increased by more than threefold in China, 25% in Japan and 45% in the European Union.

The Base Scenario also sees strong growth in high-speed rail networks, particularly over the coming decade. As has been the case over the past decade, China accounts for a large share of high-speed rail developments; nearly half of those projects undertaken between now and 2050 are in China. The result is strong activity growth on high-speed rail: passenger movements in China increased more than threefold, while those in Japan increased by 85% and by 66% in the European Union. Construction of non-urban rail infrastructure in India is particularly notable, supporting volumes of passenger activity that, by 2050, are unparalleled anywhere in the world. However, despite impressive global growth, rail does no more worldwide than maintain its current share in activity relative to personal cars and passenger air travel by 2050. Global freight activity across all categories nearly triples in 2050 from 2017 levels.

The strong growth of rail activity in the Base Scenario brings up rail energy demand: by 2050 rail electricity use reaches nearly 700 TWh. By 2050, 97% of passenger rail movements and two-thirds of freight take place on electrified rail, meaning that rail remains far and away from the most electrified of all transport modes. Rail’s energy use, however, pales in comparison with the energy it saves by diverting traffic from other modes. In 2050, if all rail services were performed by cars and trucks, oil demand would be 9.5 mb/d higher (or 16%) higher than in the Base Scenario. GHG emissions from transport would increase by 1.8 Gt CO2-eq (or 13%) above the Base Scenario in 2050. Fine particulate matter (PM2.5) emissions would rise by 340 kilotonnes (kt).

The High Rail Scenario explores how these benefits might be further capitalised. The scenario rests on three pillars:

  • Minimising costs per passenger-kilometre or tonne-kilometre moved by ensuring maximum rail network usage, removing technical barriers and integrating rail services seamlessly into the portfolio of available mobility options.
  • Maximising revenues from rail systems, such as through ‘land value capture’, i.e. capitalising on the ‘aggregation’ capacity of railway stations whereby commercial and residential properties in their proximity increase in value due to improved mobility options and greater activity, and using this value to finance rail systems.
  • And implementing policies that ensure that all forms of transport pay adequately for the impacts they generate.

Traditionally this has been accomplished through fuel taxes, but road pricing, and especially congestion charging, may be effective going forward. In the High Rail Scenario, global passenger activity on rail grows to a level that is 60% higher than in the Base Scenario in 2050, and freight activity is 14% higher. Urban rail has the greatest potential for additional growth: activity on metros and light rail in 2050 is 2.6 times higher than in the Base Scenario, concentrated in densely populated cities in China, India and Southeast Asia. The High Rail Scenario also captures the potential for high-speed rail to provide a reliable, convenient and price competitive alternative to short-distance intra-continental passenger air services. Activity on high-speed rail in the High Rail Scenario is 85% higher than in the Base Scenario, reflecting strategic investments in this mode.

Aggressive, strategic deployment of rail can lead CO2 emissions in global transport to peak in the late 2030s. By 2050, oil use in the High Rail Scenario is more than 10 mb/d lower than in the Base Scenario. GHG emissions are 0.6 Gt CO2-eq lower and PM2.5 emissions are reduced by about 220 kt, the latter primarily as a result of diminished aggregate vehicle kilometres by cars and trucks. Primarily as a result of increased urban and high-speed rail operations, electricity use by rail in 2050 is 360 TWh higher than in the Base Scenario, 50% more than in the Base Scenario, an increase that is roughly equal to the current total electricity consumption of Thailand and Viet Nam combined.

Annual average investment in the High Rail Scenario in trains and rail infrastructure combined is USD 770 billion, a 60% increase over investment in the Base Scenario. The biggest part of the increased investment goes to infrastructure for urban rail (nearly USD 190 billion) and high-speed rail (USD 70 billion); the additional costs of the trains are small in comparison. As a result of these investments, in 2050 fuel expenditures are reduced by around USD 450 billion, relative to the Base Scenario. India could save as much as USD 64 billion on fuel expenditures by mid-century.

Rail activity in India

The rail activity in Indian sub-continent is set to grow more than any other country, with passenger movements in India reaching 40% of global activity. Activity in India is already among the highest in the world, being second only to China for passenger movements and fourth for freight movements. Rail remains the primary transport mode in India connecting numerous cities and regions. Indian Railways is also the country’s largest employer. As a result, the railway network in India is sometimes referred to as the lifeline of the nation. Guaranteeing affordable passenger mobility by rail to the entire population has always been a priority in India. Today rail passengers in India travel 1.2 trillion kilometres, more than the distance travelled by cars; and about one-third of total surface freight volumes are transported by rail, a very high share by global standards. By far, coal is the predominant commodity carried on freight trains today in India.

Indian Railways is spearheading a wide range of ambitious undertakings. Construction has started on the first high-speed rail line. The total length of metro lines is planned to more than triple in the next few years. Two dedicated freight corridors are planned to enter operation in 2020. The country is set to double, or possibly even triple, existing capacity on the most utilised rail routes, and it aims to electrify the entire broad gauge network by 2022. With these and other measures realised in the Base Scenario, rail passenger movements almost triple and freight movements more than double over current levels by 2050. Electricity consumption from rail operations increases by nearly a factor of six, reaching almost 100 TWh. Electrification of highly utilised corridors leads to reductions in oil use by rail to less than 10% of current levels, reaching 3 000 barrels per day in 2050. As in other countries, rail in India saves more energy and emissions than it consumes: in the Base Scenario, rail activity in 2050 reduces oil demand by 1.6 mb/d, GHG emissions by 270 Mt CO2-eq and PM2.5 emissions by 8 kt.

Going beyond the targets captured in the Base Scenario, India has the potential to serve as an example to other emerging economies. In the High Rail Scenario, India further increases investment in railways, commissioning high-speed rail lines to connect every major city along the ‘Golden Quadrilateral’, achieves the target of doubling the share of rail in urban areas by 2050 and constructs dedicated freight corridors to connect all the largest freight hubs. Shifts in transport activity from road modes and aviation lead to additional savings in oil consumption of 1.5 mb/d, compared to the Base Scenario, and to an additional reduction in GHG emissions of 315 Mt CO2-eq and 6 kt of PM2.5.

Two categories – urban and high-speed rail – hold major promise to unlock substantial benefits both in India and throughout the world. In an era of rapid urbanisation, urban rail systems can provide a reliable, affordable, attractive and fast alternative to travel by road: metro and light rail can reduce congestion, increase throughput on the most heavily trafficked corridors and reduce local pollutant and GHG emissions. With coordinated planning, urban rail systems increase the attractiveness of high-density districts and boost their overall economic output, equality, safety, resilience and vitality of metropolises. High-speed rail can provide a high quality substitute for short-distance intra continental flights. As incomes rise, demand for passenger aviation, a mode of transport that is extremely difficult and expensive to decarbonise, will continue to grow rapidly. If designed with comfort and reliability as key performance criteria, high speed rail can provide an attractive, low-emissions substitute to flying.


On a worldwide basis, the transport sector today is responsible for almost one-third of final energy demand and nearly two-thirds oil demand. It is also responsible for nearly one-quarter of global carbon dioxide (CO2) emissions from fuel combustion and is a major contributor to air pollution, particularly in urban areas. Changes in transportation fuel use are, therefore, fundamental to achieving a global energy transition, which will guarantee energy security, alleviate air pollution and mitigate climate change. The challenge is heightened by the rapid pace of rising demand for mobility, especially in developing economies, where cities are growing exponentially, creating a need for more efficient, faster and cleaner transportation. Rail has characteristics that enable it to reduce energy demand in transport and draw on diverse energy sources. It can mitigate CO2 emissions from transport and contribute to a broader transition towards sustainability. Its particular strengths are: energy efficiency (on average, trains are close to 12-times more energy efficient than road and air travel in terms of final energy per passenger transported and 8-times more efficient than trucks per tonne of freight carried); its reliance on very diverse energy sources; and its contribution to reducing congestion on road networks. Rail provides mobility with minimal emissions of harmful air pollutants and, thanks to agglomeration effects, facilitates economic growth.

Rail today serves passenger and freight mobility needs in countries across the globe. In 2016, rail services were an important component of passenger mobility in China, India, Japan, the European Union and Russia, and provided a significant fraction of all goods movements in North America, China, Russia and India. Globally, rail constituted 8% of passenger transport and 7% of freight movements in 2016. Rail accounted for less than 2% of transport energy, far less than the sector’s share of transport activity. The reasons are multiple: the large carrying capacity of trains, compared to other modes; the high efficiency of electric motors; and the efficiency of fuel use resulting from the very low resistance offered by the steel-to-steel interface between wheels and tracks. With roughly one-third of its global energy consumed in the form of electricity, rail is also currently the only transport mode that does not rely almost exclusively on oil. The share of electricity in rail energy use exceeds 70% in major economies, such as China and the European Union. In Japan, this share is more than 90%.

In highly populated ‘megacities’, many of which are in Asia (with more yet to be built), urban rail (metro and light rail) plays a critical role in large-scale passenger movements. This form of rail travel diversifies the transport energy mix, reduces local air pollution, alleviates congestion and improves overall productivity. But there are also limiting factors. Because of its capital intensive nature, urban rail requires very high throughput in order to achieve its environmental and economic goals.

Therefore, it becomes imperative to examine the role of rail in global transport might be elevated as a means to reduce the energy use and environmental impacts of transport services. It explores plausible scenarios to 2050 in which such an enhanced role is achieved, assessing the environmental, societal and energy security implications. This analysis is guided by the essential need to respect the economic viability of rail undertakings and sheds light on the key instruments that can turn potential benefits into actual achievements. Crucial components of the solutions identified are:

  • Minimising costs per passenger-kilometre or tonne-kilometre moved, ensuring that the preconditions for maximum rail network use are in place (e.g. through urban planning measures that provide integration of different modes of transport with rail networks), taking steps to remove technical barriers (e.g. through the adoption of international standards which facilitate inter-operability) and fully exploiting digital technologies to ensure that rail services are well integrated into the range of mobility options available to passengers and freight users.
  • Maximising revenues from rail systems, capitalising on the “aggregation” capacity of railway stations (land value capture), a model which has already made several rail systems profitable. In this model, the increase in value of commercial and residential properties in the proximity of stations that arises as a result of improved mobility options and greater activity is “captured” to finance rail systems.
  • Ensuring that all forms of transport pay not only for the use of the infrastructure they need but also for the impacts they generate (e.g. through road pricing and congestion charges). The opportunity for effective action on this front will be enhanced by increased transport electrification and the transition towards road vehicle automation, both of which are likely to require price signals to modulate demand.

The transport sector is responsible for almost one-third of final energy demand, nearly two-thirds of oil demand and nearly one-quarter of global carbon dioxide (CO2) emissions from fuel combustion. Therefore, changes in transportation are fundamental to achieving energy transitions globally. While the rail sector carries 8% of the world’s passengers and 7% of global freight transport, it represents only 2% of total transport energy demand, highlighting its efficiency.

The rail sector can provide substantial benefits for the energy sector as well as for the environment. By diversifying energy sources and providing more efficient mobility, rail can lower transport energy use and reduce carbon dioxide and local pollutant emissions.

Rail serves a vital lifeline of India, playing a unique social and economic role. In India, Rail remains the primary transport mode in the country, which provides vital connections between cities and regions and guarantees affordable passenger mobility. Rail passenger traffic in India has increased by almost 200% since year 2000 yet prospects of future growth remain bright. Construction has started on India’s first high-speed rail line, the total length of metro lines is set to more than triple in next few years and two dedicated freight corridors are on track to enter operations by 2022.

Indian Railways also plans to convert diesel locomotives to electric locomotives towards its ambitious goal of a hundred percent electrification of the Indian Railway.

In all countries, including India, the future of rail sector unarguably shall be determined by how it responds to both rising transport demand and rising pressure from other transport modes.

The above topic ‘Rail Transportation: Creating Opportunities for Energy & Environment is one of the many topics which will be covered in the InnoMetro event. This 2-day event is an insightful expo and conference on the metro and rail industry and would definitely open doors of possibilities.

To join the 2nd edition of InnoMetro to be held from 23rd-24th May 2022 at The LaLit, New Delhi, click on the links below.

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