UK transport decarbonisation strategy– impact for rail sector

United Kingdom

On 14 July 2021, the UK Department for Transport (“DfT”) published a wide-reaching policy plan on decarbonising transport and the targets and ambitions required to meet the UK’s net-zero targets (the “Decarbonisation Plan”). This is one of a number of CMS papers considering the proposals set out in the Decarbonisation Plan (and associated consultation policy papers) with this paper focusing on its impact on the rail sector.


The Decarbonisation Plan recognises the importance of rail in delivering its green transport objectives for people as well as goods. It has been published against the backdrop of significant ongoing investments in rail infrastructure as well as the recent changes in the ownership structure of the rail system and the formation of Great British Railways. This is something that the Decarbonisation Plan points to as a positive step with the bringing together of the rail system under a single organisation which is responsible for achieving the commitments set out in the plan.  

The Decarbonisation Plan notes that rail is already lower carbon than other long-distance transport and is becoming even less carbon intensive as the electricity system decarbonises, with GHG emissions from rail making up 1% of the 2019 domestic GHG emissions despite 9% of passenger miles coming from rail.  Although it notes that rail is already the greenest form of motorised transport, only 38% of the network is electrified so there is plenty of scope for improvement including the need to speed up the development of battery and hydrogen trains for areas where electrification is impossible or too costly.

Coupled with this is a recognition of the need for modal shift to public and active forms of transport. Rail can have a big part to play but this can only be achieved (and even only realistically encouraged) when the entire rail network is more reliable, faster, cleaner, as well as competitively priced. Following publication of the Decarbonisation Plan, the Rail Delivery Group has called for the rail fares system to be restructured to make it easier for people to transition to greener forms of transport using a “polluter-pays” approach.

Published alongside the Decarbonisation Plan are the Jet Zero Consultation, the non-zero emission HGV Phase Out Consultation, a Green Paper on a New Road Vehicle CO2 Emissions Regulatory Framework for the United Kingdom and the Rail Environment Policy Statement – all part of a series of policy announcements in the run-up to COP26.

Core Commitments

The core commitments in the Decarbonisation Plan include: 

  1. delivering a net-zero rail network by 2050, encouraging more freight onto the rail network and stimulating regeneration through government investment in areas such as technology, infrastructure and electrification;

  2. removing all diesel-only trains from the rail network by 2040, deploying newer technologies such as hydrogen and battery trains as well as further investment in electrification – Network Rail’s Traction Decarbonisation Network Strategy estimates that 97% of emissions could be removed by 2050 under assumed levels of green technologies;

  3. building extra capacity (including HS2) to meet growing demand and support modal shift;

  4. modernising fares and ticketing and encouraging rail journey connectivity by creation of mobility hubs and increasing space for bikes on trains;

  5. introducing a rail freight growth target - rail freight currently emits around 1/4 of the CO2 emissions of HGVs per tonne mile travelled - and incentivising lower carbon rail freight through technologies such as ‘stop-start’ systems; 

  6. air quality targets will be set for all parts of the railway in 2022 with the aim of meeting those targets by the end of 2030.

Rail Environment Policy Statement

The Rail Environment Policy Statement sets out the environmental priorities for the mainline railway across Greta Britain. Many of these echo the Core Commitments noted above; additional priorities include:

  1. development of air quality improvement plans for certain pre-identified stations;

  2. Network Rail achieving net zero biodiversity by 2024 and biodiversity net gain by 2035;

  3. zero waste from railway activities (including passengers) going to landfill by 2025;

  4. Network Rail cars and vans to be zero emission by 2027; and

  5. targets being set for renewable energy generation and use at stations.

The Policy Statement asserts that the establishment of Great British Railways will better support the delivery of these objectives, it being better able to make a holistic assessment of the entire network. In this regard it is encouraging to read that a specific statutory duty will be placed on Great British Railways to consider environmental principles in all of its operations.

With only around two fifths of the rail network having electric infrastructure, the Policy Statement notes that battery / biodiesel / hydrogen fuelled trains may be the preferred method of decarbonisation in some areas – further strategy on this is due to be published in 2022.

Finally, the National Infrastructure Commission’s Future of Freight programme continues to be developed so further proposals for that part of the sector will doubtless appear when the policy route map is published.


The Decarbonisation Plan and associated documentation plot an ambitious and laudable course to achieving net zero but are light on the detail of how we will get there. Given the scale of these proposals, it is also surprising that there is no mention of how these proposals will be funded, save for acknowledging that delivering the plan will require major investment both public and private and indicating that the new UK Infrastructure Bank will have a role to play.

Although the process to remove diesel-only trains from the network has been underway for some time – with a number of operators having introduced new fleets of bi-mode diesel-electric trains, and the first programme to introduce retrofitted tri-mode vehicles underway. With the average life of rolling stock being 30 years it is all the more important that these developments and the development of hydrogen trains is accelerated, if the DfT is to have any hope of achieving its commitment to remove all diesel-only trains from the network by 2040. 

As has been seen in other industries, clarity is needed for the rail industry to galvanise its efforts in changing existing practices. It is entirely likely that the course proposed by the Decarbonisation Plan will have to be altered to account for obstacles along the way and multiple further questions will need to be answered before the UK can truly be on its way to decarbonisation.

Please see here for our analysis of the proposals for passenger and freight transports in respect of EV charging and hydrogen fuelling.