Public Transport: Moving Cities Towards a Sustainable Future

Environmental challenges hang heavily over the transport sector. For example, transportation accounts for around 64% of all oil consumption, 27% of global energy use, and 23% of the world’s energy-related CO2 emissions [1]. Answering why these figures are so high is a lengthy process. However, some answers immediately reveal themselves when we look at our transportation practices. Specifically, we are mainly dependent on private mobility. 

This over-reliance is problematic when projections indicate that, by 2050, public transportation has the potential to cut transport emissions by more than half [2]. However, such impressive statistics are premised on numerous factors, like how often the public uses urban transit systems and their general emission production.

Why is public transport sustainable?

Generally speaking, choosing public over private transport emits fewer emissions. Consider the bus, for example: if everyone switched just one car journey a month to a bus, 2 million tonnes of carbon dioxide emissions could be saved [3]. This is because a full, single-decker bus equates to 40 cars, and a packed double-decker bus is equivalent to 75 cars [4].

Even when we look at statistics for trains, it is clear they are more environmentally friendly. On average, the Eurail produces around 3 times less CO2 emissions per person when compared to a car [5]. Alongside this, trains also use less space and have lower noise pollution levels [5]. Keeping these facts in mind, then, it seems that public transport might hold the key to sustainable mobility. However, it is not as clear-cut as we might initially think.

Moving towards sustainability.

Problems start to arise when there is a small passenger demand on public transport. A study by researchers at the Tokyo Institute of Technology found that low demands can have a contrary effect on emission savings and result in a higher energy consumption per passenger compared to private mobility [6]. To make matters worse, having such low demand is not unheard of, as public transport is not usually the first choice of many travellers. Ensuring that public transport is operating at an emissions-efficient level, therefore, requires a modal shift.

Driving a modal shift towards public mobility is no easy task, though. While the challenges vary from city to city, the public typically raises issues related to public transport pricing and its difficulties. However, these grievances have not been left unheard, as the National Bus Strategy plans to revolutionise bus services in a bid to encourage the public to take the bus [7]. In a document produced by the Department for Transport, these goals include lower and simpler fares, more frequent buses, easy-to-use and understood services, more bus priority lanes and thousands more carbon-free buses [7].

The push for this modal shift has been invested in more broadly too. In particular, the UK government is allocating £4.8 billion of investment into the Levelling-Up Fund. Within this is a themed investment into transport, which encompasses public transport improvements and bus priority [7]. Funding like this will help drive a modal shift towards public transportation by helping resolve some of its central issues.

Besides this, another vital way to ensure urban transit systems are emission-effective is to invest in decarbonising them. Thankfully, progress has been made toward this. In 2020, for example, 5,565 new e-buses were registered in the EU with a projected conversion rate of 45% in 2025, rising to 65% in 2030, respectively [4].

As Transport Secretary Grant Shapps said, electric buses will not only “improve the experience of passengers, but it will help support our mission to fund 4,000 of these cleaner buses, reach net zero emissions by 2050 and build back greener” [8]. Further, stating that this drive is a part of the National Bus Strategy, which is designed to “introduce lower fares, helping drive down the cost of public transport even further for passengers” [8].

Decarbonising public transport has expanded beyond the roads too. Even though the government has been electrifying Great British Railways since 2010, they recognise that these efforts need to be extended [9]. In a rail environment policy statement, it is claimed that the rail industry is to be set on a path towards sustainability via decarbonisation, air quality, and other environmental-related issues on the railway, including biodiversity and waste [9]. Railways, then, are steering toward a sustainable future, independent of passenger demand.


While public transport has the potential to steer the sector into sustainability, currently, there are issues with it. To resolve these issues, we must first ensure that we are encouraging a modal shift towards public transport and producing carbon-free transportation. But, even with these changes happening now, it could be questioned: are they happening fast enough?


  1. L. Mead, “The Road to Sustainable Transport,” IISD, 24 May 2021. [Online]. Available: [Accessed 16 June 2022].
  2. M. Kinver, “Public transport holds key for clean cities, says study,” BBC, 17 September 2014. [Online]. Available: [Accessed 16 June 2022].
  3. Transport for Greater Manchester, “Public transport and the environment,” 2022. [Online]. Available:,encourage%20a%20more%20active%20lifestyle.. [Accessed 16 June 2022].
  4. Bus News, “The Importance of Public Transport for a Sustainable Future,” 6 October 2021. [Online]. Available: [Accessed 16 June 2022].
  5.  Eurail, “Why Eurail is your greenest choice,” [Online]. Available:,are%20far%20more%20sustainable%20too.. [Accessed 16 June 2022].
  6.  K. Masanobu and S. Hanaoka, “Comparison of sustainability between private and public transport considering urban structure,” IATSS Research, vol. 27, no. 2, pp. 6-15, 2003.
  7. Department for Transport, “Decarbonising Transport: a Better, Greener Britain,” 2021. [Online]. Available: [Accessed 16 June 2022].
  8., “UK on track to reach 4,000 zero emission bus pledge with £200 million boost,” 26 March 2022. [Online]. Available: [Accessed 19 June 2022].
  9., “Transport decarbonisation plan,” 14 July 2021. [Online]. Available: [Accessed 16 June 2022].