Buses have a crucial role to play in the UK’s path to net zero – both to achieve modal shift and decarbonise our transport system. Over the last few years buses have become central in the public discussion over the future of transport – but are we in the midst of a green bus revolution?

Road transport is currently responsible for around a quarter of greenhouse gas emissions in the UK, of which around 4 per cent is attributable to buses. Whilst these numbers might not seem as considerable in the bigger picture, the action taken to green buses is a key part of the wider transport decarbonisation agenda.

Buses are among the most carbon efficient modes of passenger transport, with the pre-coronavirus (2018/19) average passenger loading of 12.2 people on the bus at any given time over the course of the operating day. Simply put, a double decker can remove 75 cars from the road.  Battery electric buses have a similar advantage over electric cars in terms of lower emissions per passenger-kilometre.

The Government has made decarbonising vehicle fleets a policy priority and made significant funding available for this task. The Bus Back Better strategy has zero emission bus delivery at its core, with the government pledging to ‘provide the financial support to scale up quickly’ and take a place-based approach to achieve this. The Department for Transport’s Transport Decarbonisation Plan relies on delivering the National Bus Strategy to achieve a ‘green bus revolution’, with 4,000 new zero emission buses on the roads by the end of the current Parliament, along with the necessary infrastructure.

Whilst significant amount of government funds has been allocated towards this goal, various transport sector stakeholders, amongst them the Transport Select Committee, conclude that it is unlikely that the 4,000 target will be met in the remining time, given how few of the ‘funded’ vehicles are now on the road. According to the Zemo partnership research, whilst Zero Emission Buses (ZEBs) funded through Ultra-Low Emission Bus Schemes (ULEB) in England and Scotland, are almost 100 per cent in service today, progress has been considerably slower to date for the Zero Emission Bus Regional Areas (ZEBRA) Schemes with only 47 vehicles in service through the ZEBRA fast track projects (in Cambridge and Peterborough Combined Authority, Leicester City Council, Kent County Council, Warrington Borough Councils).

Despite this, the current bus decarbonisation picture isn’t as bleak as it might seem – but should be viewed within the context of bus sector decline, which has been further impacted by the pandemic.

An average of 513 new ZEBs have been registered per year over last three years (2020-2022), totalling 639 in 2022 – equating to around 50 per cent of total bus uptake in the UK. So far in 2023, ZEBs have accounted for over 70 per cent of all new registrations – that is a considerable jump from, for example, 2019, when approximately only 10 per cent of all registrations were ZEBs. The Zemo Partnership expect zero emission registrations to account for between 50-60 per cent of total bus uptake by the end of 2023, with battery electric vehicles continuing to make up the majority of these vehicles.

Alongside promoting modal shift, our members are investing heavily in supporting the decarbonisation of these vehicles.

Transport for London (TfL) has set a goal of having a fully zero emission bus fleet by 2034 or sooner. This accounts for over 9,000 buses or a one-third of the English bus fleet. Progress is accelerating in London - there are now over 1,000 zero-emission buses in the fleet (consisting of electric and hydrogen buses). All new TfL buses entering the fleet are required to be zero-emission. This success is down to close collaboration between TfL, operators, manufacturers, and infrastructure providers.

West Midlands currently has the second largest zero emission fleet in the country after London. A fleet of 124 new environmentally friendly hydrogen fuelled buses will be taking to the streets of the West Midlands soon, joining the 20 hydrogen double decker buses, bought by Birmingham City Council and operated by National Express West Midlands currently. It means the region will have 144 hydrogen buses on the streets, the largest fleet in the Western World. This also points to a wider positive picture in the sector - hydrogen is no longer a competing but rather complimentary technology, although the supply and cost of hydrogen fuel remains a challenge.

Last year, the region secured £50 million government funding to create the UK's first All Electric Bus City in Coventry by 2025 - a project which will also deliver cleaner air and lower carbon footprint, and see up to 300 fully electric buses operate across the city.

London and the West Midland’s experience and success was shared at a Zemo Partnership conference, which I had the pleasure to attend last month. The conference brought together transport stakeholders from across the UK to engage on the challenging topics concerning acceleration of our transport networks to zero emissions.

During a panel discussion on the future of decarbonising buses, a complex picture emerged – there is significant positive movement, but the task is being hampered by lack of funds and infrastructure, as well as a comprehensive and clear central strategy. Obtaining funding and placing orders are slow and piecemeal processes, and it is too difficult for UK manufacturers to invest with confidence in new types of vehicle and manufacturing hubs. There is a need for greater cohesion of national policy with less fragmentation between the approach taken to different transport modes.

UTG has previously explored what change needs to take place to tackle the challenges facing transport authorities and operators in decarbonising their fleets. Such challenges range from staffing capacity at local authorities, a lack of cohesive national policy and the absence of strategic and coordinated funding, delayed BSOG reform, proliferation of different specifications, lack of coordinated approach to the regulations surrounding the framework (grid, planning, highway regulations) and a fragmented approach to the production pipeline.

Specifically on buses, we have been running a series of events (together with design company Arup) on how we transition to zero emission buses in our city regions. The series is focusing on sharing best practice and experience from across our network, and to date, sessions have focused on data and mapping, zero emission park and ride schemes, and the lessons learned from procuring zero emission buses.

Overall, it’s a promising picture – there is clearly scope to deliver, but that can only happen with a coherent and holistic strategy on decarbonising all vehicles backed by longer term reliable funding and streamlined application process. We have started a green bus revolution, but its future and success depends on tackling these challenges urgently.

Monta Drozdova is Policy and Research Advisor at the Urban Transport Group