The LTPs being developed by many authorities will play a crucial role in shaping the policies and interventions needed to reduce carbon emissions over this critical period. They will be even more important with more devolved authorities and local government reorganisation.

If climate commitments are to be met, these LTPs must establish the vision and practical solutions that will decarbonise emissions at the urgent pace required. A credible strategy, however, must be evidence-led and focused on the emissions in LTAs’ influence, while acknowledging the trade-offs and interdependencies with other stakeholders and levels of government.

The Quantifiable Carbon Guidance (QCG) guidance published by the Department for Transport (DfT) in August 2025 provides an evidence-led approach that remains best-practice. This guidance, alongside tools developed by Sub National Transport Bodies, both of which WSP helped develop, provides the process, evidence and proportionate methodologies needed. This provides an understanding of the local scale of the challenge and emissions sources, as well as an ability to test carbon impacts of different outcomes and interventions. 

LTAs with LTPs that align to decarbonisation commitments and demonstrate quantifiable carbon reductions will be better placed to articulate why bold policies and interventions are needed and to answer any challenges on climate grounds. 

It also places LTAs in good stead when providing assurance to central government on their maturity to deliver LTPs in-line with new single settlement funding streams that are the direction of travel for local authority transport and infrastructure funding. Alignment with decarbonisation commitments may strengthen the case for a greater settlement. 

To achieve our climate commitments, we need to move beyond business-as-usual policies. Improvements in sustainable transport infrastructure are vital but unlikely to be enough. 

We must therefore strive for a transformative transport system by taking bold measures. Whether through behavioural change programmes, changes in capacity for different modes or pricing measures, the external costs of travel and characteristics of the system we are seeking to create can be better reflected. 

These interventions in some places will be necessary to reduce private car use at the required scale and pace. They also provide significant co-benefits that help make the case for change, including:

• Improving air quality and health outcomes;
• Economic benefits from reduced congestion and more attractive, people-centric places;
• Additional revenue for local transport improvements.

If we take a ‘do-minimum’ approach, we risk increased private vehicle use and congestion, heightening our vulnerability to the impacts of climate change. This future will see worsening road conditions and more frequent disruptions.

While challenging, delivering demand management measures is achievable. Currently, we manage demand through fares, parking charges and fuel duty, but a more proactive approach could better support an equitable transition to our net zero goals. A way forward, however, should also include urgent delivery of alternatives to private vehicles and designing inclusive policies. Engaging stakeholders and affected communities by presenting them with a clear and compelling narrative of the benefits will be essential to maintaining strong support.

Carbon analysis in LTPs will help LTAs articulate the ‘carbon case’ for bold policies and highlight wider benefits. Cities like London, Oslo, and Milan demonstrate what a positive, low-carbon future can look like.

The transport schemes we deliver, and how we deliver them, will significantly impact our ability to meet decarbonisation commitments. When infrastructure related carbon impacts from construction and maintenance are considered, even ‘sustainable’ programmes are at risk of delivering underwhelming carbon reductions or even increases in carbon emissions. 

It is critical, therefore, that schemes adopt a process of carbon management aligned to the now widely adopted global standard for managing carbon, PAS 2080. This should involve embedding evidence-led consideration of carbon from the earliest stages of scheme development; seeking to maximise user emission savings such as modal-shift and minimise carbon impacts such as capital carbon in construction. Where done properly, this can reduce cost as well as carbon.

For major programmes and settlements, such as the Transport for City Regions (formerly City Region Sustainable Transport Settlement) it is recommended that a programme-wide carbon management approach is adopted. This should define a best practice and proportionate approach to give project teams clarity on expectations and ensure consistent outputs. It enables common issues and challenges to be tackled at a programme level to save time and cost and raise carbon capabilities and skills consistently across organisations and departments. This approach will also enable programme-wide reporting of carbon impacts.

It’s time for LTAs to make their decarbonisation plans happen. Opportunities await — WSP has the expertise to help you unlock them. We believe the three areas identified above are essential ingredients for a credible just-transition to net zero and the many wider benefits this will unlock.