Transport Net Zero: An Integrated Approach

The UK's transportation sector remains a significant contributor to greenhouse gas emissions, accounting for nearly 30% of the nation's total. Despite advancements in other areas, transportation emissions have seen minimal reduction in recent decades, underscoring the urgency for comprehensive decarbonisation strategies. Between 1990 and 2022, domestic transport emissions decreased by 12%, while total UK domestic emissions fell by 50% in the same period, indicating that transportation emissions have seen minimal reduction compared to other sectors.¹

The critical question arises: Should efforts focus on reducing emissions across all transport modes or encouraging a shift towards lower-emission alternatives, or a combination of both?

_{Greenhouse gas emissions by sector, 2021, by proportion (DESNZ, 2023) Source: Transport and environment statistics: 2023 - GOV.UK}

Decarbonising Transport: Current Progress

Efforts to reduce emissions across the transport sector are underway, with various initiatives shaping the transition to a more sustainable future. The UK government has laid out a comprehensive plan to decarbonise the entire transport system through the Transport Decarbonisation Plan. This plan includes commitments and actions needed to achieve net zero transport by 2050². But there is more work to do to drive an integrated approach.

The Government's zero-emission vehicle mandate has accelerated electric vehicle (EV) adoption, with battery electric vehicles accounting for 16% of new car registrations in 2022. The mandate aims for 80% of new cars to be zero-emission by 2030. However, achieving this target necessitates a rapid expansion of public charging infrastructure to support the growing number of EVs.

Behavioural shifts in London are evident, with car ownership decreasing by 70,000 between 2016 and 2023 as more people opted for buses, trains, cycling and walking. This decline, combined with policies such as the Ultra Low Emission Zone (ULEZ), has led to significant reductions in vehicle emissions. Together, these measures have improved air quality and reduced overall emissions, highlighting the crucial role of public transport and active travel in achieving sustainability goals.³

^{Indicative GHG emissions (KgCO2e) for a single passenger on example journeys, 2023 Source: Transport and environment statistics: 2023 - GOV.UK}

In the rail sector, the Transport Decarbonisation Plan sets out an ambitious goal of achieving a zero-carbon rail network by 2050. This strategy focuses on electrifying rail lines, reducing reliance on diesel-powered trains and integrating low-carbon energy sources into operations. Additionally, measures to improve energy efficiency in stations are being introduced, ensuring that rail infrastructure supports wider sustainability objectives. These objectives are supported by the Rail Environment Policy Statement (REPS), which sets out a clear direction for the rail industry on key sustainability requirements⁴.

Similarly, the aviation industry is exploring innovative solutions to reduce its environmental impact across both flight emissions and infrastructure emissions. Exact percentages vary, but it is estimated that flight emissions account for 90-95% of the emissions from the aviation sector with the other 5-10% come from airport infrastructure and ground operations⁵. In 2021, the UK aviation industry made a commitment to be net zero carbon by 2050. The challenge ahead is immense, but with credible plans in place, the industry hopes the target can be delivered with the right support.

Find out more in our article Net Zero Aviation: Preparing the Infrastructure for Take-Off.

Specifically relating to infrastructure, airports across the UK, such as London Gatwick and Heathrow Airport, have implemented sustainability strategies and programmes of work to both enhancing their existing infrastructure and reduce their environmental impact to achieve net zero. These efforts reflect a broader push within the industry to balance operational demands with the need to cut carbon emissions.

Case Study

We are working with Gatwick Airport to enhance its future supply chain strategy, focusing on sustainability and efficiency to support the airport's long-term growth and environmental goals. Click here to read our case study.

The UK also has several initiatives in place to decarbonise its highways. The Government has allocated £30m funding to support 7 local highways authorities to tackle the long-term decarbonisation strategy⁶. National Highways also announced an ambitious carbon plan to achieve net zero emissions by 2050. This plan includes commitments to achieve net zero for its own operations by 2030, deliver net zero road maintenance and construction by 2040, and support net zero carbon travel on roads by 2050.⁷

Key Challenges in Delivering Transport Decarbonisation

As these initiatives progress across the respective sectors, they mark significant steps toward decarbonising key transport sectors and creating a more sustainable infrastructure for the future. But while these initiatives represent a positive step forward, they also come with a set of challenges that must be carefully managed to ensure their success, as a collective transportation sector.

Financial Investment

One of the most pressing concerns is the financial investment required. Implementing these initiatives demands significant upfront capital, and while the long-term benefits may be substantial, returns are often realised only in the medium to long term. This can create financial strain, particularly for organisations that must balance immediate costs with future gains.

Embodied Carbon

Additionally, the issue of embodied carbon cannot be overlooked. Construction and infrastructure projects contribute to carbon emissions and achieving sustainability goals requires a meticulous approach to material selection and building methods. Striking a balance between environmental responsibility and practical feasibility remains a key challenge.

Complementary Infrastructure Development

Grid capacity is a known challenge as decarbonisation projects drive an increase in demand, from increased EV charging points to electrification of building services. In order to decarbonise the UK transport industry at the pace required, there is a reliance on complementary investment and development by network operators.

Supply Chain Appetite

Beyond environmental considerations, supply chain constraints present another significant hurdle. The effectiveness of these initiatives depends on a supply chain that has both capability and capacity to deliver against the evolving government standards and regulations, such as PAS 2035 and PAS 2080 - frameworks for sustainable practices in construction, infrastructure and retrofit projects, supporting the UK’s net-zero carbon and climate resilience goals. PAS 2035 is the Whole-House Retrofit Standard and PAS 2080 is the Carbon Management in Infrastructure standard. Ensuring that the entire supplier network meets these stringent requirements requires coordination, investment and, in some cases, industry-wide adjustments.

Find out more in our article If you build it, they will come...but only if the supply chain is willing!

User Experience

Finally, there is the matter of user experience. While these improvements aim to enhance infrastructure and sustainability, their direct impact on the end user may not be immediately apparent. If benefits take time to materialise, public perception and engagement could be affected, making it more challenging to secure widespread support for these initiatives.

Addressing these challenges requires a strategic, well-coordinated approach that balances financial viability, environmental impact, regulatory compliance, supply chain appetite and user engagement to ensure the long-term success of these initiatives.

Encouraging Low-Emission Travel

Encouraging the widespread adoption of low-emission transport modes requires a fundamental shift in how public transport is designed, experienced and integrated into daily life. One of the most effective ways to achieve this is by enhancing the overall user experience. Making public transport more appealing through modern, well-maintained facilities, improved accessibility and enhanced safety measures can significantly influence people’s travel choices. A system that is clean, efficient and comfortable will naturally attract more users.

Capacity expansion is another critical element in this transition. Increasing the frequency of services reduces wait times and minimises overcrowding, making public transport a more reliable and attractive alternative to car travel. The more accessible and available a service is, the greater the likelihood that individuals will opt for it over higher-emission alternatives.

Cost efficiency plays a significant role as well. By reducing operational costs and passing these savings on to users, public transport can become a more financially viable option for a broader population. When combined with government incentives, subsidies, or fare integration schemes, lower costs can further encourage people to move away from private vehicle use in favour of more sustainable options. Life Cycle Costing aids early-stage decision-making, from benchmarking for strategic business cases to detailed as-built life cycle replacement and maintenance cost plans.

Beyond individual transport modes, integrating various systems into a cohesive intermodal network is essential. A well-connected system allows passengers to move effortlessly between different modes of transport—whether from a national rail service to a local bus, a tram or even an e-bike rental. Operational integration, such as unified ticketing systems that work across multiple transport providers, simplifies the user experience and removes unnecessary barriers.

Regional connectivity must also be improved, linking national transport networks with local options such as buses, trams and subways. A well-connected system allows passengers to complete an entire journey seamlessly without requiring a private vehicle for the last leg.

Finally, where car travel is still necessary, investing in EV infrastructure is vital. Adequate charging facilities must be available to encourage the shift to electric vehicles, whether for personal use or commercial transport, such as London’s growing fleet of electric taxis. Without the necessary charging infrastructure, the transition to EVs will remain slow, limiting the overall impact on emissions reduction. Cross-sector collaboration will be critical for easing the pressure on District Network Operators to provide electrical capacity in the right places.

Taken together, these measures create a transport system that is not only environmentally sustainable but also user-friendly, efficient and accessible. By making public transport a more attractive and practical option, we can drive behavioural change and significantly reduce emissions across the sector.

These strategies face challenges, including financial constraints, embodied carbon from necessary infrastructure projects, supply chain limitations and the need for coordinated operational changes across the transport sector.

Global Context: Lessons from International Leaders

While the UK faces significant challenges in decarbonising its transport sector, other countries have demonstrated effective strategies that could inform its approach. Norway leads the world in electric vehicle (EV) adoption, with over 80% of new car sales in 2023 being fully electric, driven by strong government incentives, extensive charging infrastructure, and tax exemptions. Meanwhile, Germany has made substantial progress in rail electrification, with over 60% of its railway network now electrified, reducing reliance on diesel trains and cutting transport emissions. Additionally, cities such as Amsterdam and Copenhagen have successfully integrated cycling and public transport networks, significantly reducing car dependency. By examining these global best practices, the UK can identify scalable solutions that align with its net-zero ambitions and address the specific challenges of its transport system.

A Call for Collaborative Action

Achieving net zero across the transportation sector requires a unified approach that combines infrastructure improvements with initiatives to influence travel behaviour. Investment strategies must balance decarbonisation efforts with enhancements to infrastructure and intermodal connectivity. Evaluating the embodied carbon of projects is essential to ensure that environmental benefits outweigh the impacts of construction.

Supply chain readiness is another critical factor. Addressing capacity and capability through visibility, engagement, and expansion initiatives will support the successful delivery of major programmes.

Collaboration among government entities, transport operators, regulators, trade bodies and other stakeholders is paramount. Aligning carbon reduction plans and sharing best practices will facilitate the development of an integrated, efficient and sustainable transport network – drawing lessons from international leaders in transport decarbonisation.

At Gardiner & Theobald, we work with clients to support sustainable transformation in the UK's transportation sector. With extensive experience in infrastructure delivery, we are providing expertise in navigating the transition towards net-zero emissions. By collaborating with industry partners and exploring practical solutions, we are supporting clients in developing a more efficient, interconnected and environmentally responsible transport network.

Find out more here.

Final Thoughts

In conclusion, the UK's transportation sector is at a critical juncture in its journey towards decarbonisation by 2050. While progress is being made through various government initiatives, sector-specific and individual client strategies, substantial challenges remain which impact not only the transport sector but infrastructure decarbonisation efforts more broadly.

Financial investment, managing embodied carbon, ensuring grid capacity and supply chain constraints are significant challenges that need to be addressed. Enhancing user experience and encouraging low-emission travel are also crucial for achieving sustainability goals, but this cannot be achieved by individual sectors or clients. A coordinated, sector-wide commitment is essential to integrate different clients, requirements, and objectives. By collaborating, staying informed about innovations, and developing future-proof and actionable strategies, we can shape a sustainable transport sector to ensure long-term success.

^Sources:

1. ^{Greenhouse gas emissions from transport in 2022 - GOV.UK}
2. ^{https://www.gov.uk/government/publications/transport-decarbonisation-plan}
3. ^{Transport for London, London Government, London Government}
4. ^{https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1002166/rail-environment-policy-statement.pdf}
5. ^{https://www.statista.com/topics/12910/aviation-emissions-worldwide/#topicOverview}
6. ^{https://www.gov.uk/government/news/30-million-government-funding-for-innovative-projects-to-decarbonise-uk-highways}
7. ^{https://nationalhighways.co.uk...}