Three elements to unlock private investment in transport infrastructure

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Transportation

Colette Carroll

Director, Transportation UK & Ireland, London, UK contact form

Colette Carroll, AtkinsRéalis Managing Director for Transportation, UK & Ireland, outlines how a clear investment playbook, empowered regions and innovation can unlock private capital to deliver place-led growth

Sixty years ago, London's Victoria Line may never have made it off the drawing board. But a new approach to assessing transport schemes changed how we recognise their potential. By factoring wider social benefits – including economic growth and reduced road congestion - into cost-benefit calculations, planners secured approval for what would become an essential artery of the capital.

This new method didn't just greenlight a tube line, it reflected how the true value of connectivity extends far beyond the journey itself. It mirrors what we understand today as place-led growth: a more holistic view of infrastructure which integrates with local aspirations to deliver sustainable development.

But with the UK facing an unprecedented renewal programme to upgrade our ageing networks, private funding is vital to get schemes off the ground. Transportation remains our most disproportionately publicly funded infrastructure sector, according to the last NIC pipeline, with every £4 stumped up by taxpayers matched by only £1 from mixed public-private investment. Yet, EY says the UK could unlock £326 billion in transportation infrastructure by matching private funding levels of countries like Canada or Australia.

While the government has set in motion important planning reforms that will facilitate infrastructure delivery, more is needed to secure investment and deliver place-led growth: a comprehensive “playbook” setting out the models available, devolved authorities with appropriate capabilities, and an industry embracing innovative delivery techniques. A stable and predictable infrastructure pipeline must serve as the critical foundation underpinning all three.

From playbook to practice

I have long advocated for a comprehensive investment “playbook” for transport infrastructure. Attracting private capital requires sophisticated frameworks that recognise not all projects present equally investable propositions, with different solutions for different contexts.

A well-designed playbook would clearly outline the acceptable models for leveraging private investment, matching approaches to project types and roles across the lifecycle. It would codify frameworks and accelerate private investment by clearly articulating government-approved approaches, defining roles across the public and private sectors.

It must help public organisations assess scheme viability against various funding mechanisms –minimising taxpayer burden while maximising value. However, documentation alone cannot drive transformation. Any playbook must align with a transparent, reliable project pipeline that builds market confidence and certainty, and, just as crucially, a public sector with necessary capabilities and a refreshed appetite to risk.

Evolving the devolved

As devolution accelerates, it’s increasingly clear that local authorities will have to build business cases in ways that measure and quantify place-led values. Devolved authorities with appropriate skills and powers can craft locally-tailored commercial arrangements that better reflect regional priorities, creating more attractive investment opportunities.

Yet, the National Audit Office’s Lessons learned: private finance for infrastructure highlighted capability gaps within public bodies managing complex investment projects. Their analysis recognises the challenge public bodies face when building and maintaining the financial and commercial capabilities required. With private investment partners often having extensive experience across multiple projects and sectors, public authorities must have access to comparable expertise to ensure balanced and effective partnerships, protecting public interests while attracting private capital.

Building these specialised capabilities will inevitably take time, and authorities will need support while developing in-house expertise. Formal mechanisms for sharing best practices and accessing skilled resources will be essential for authorities to partner effectively with private sector organisations. This knowledge-sharing infrastructure is as important as the physical infrastructure we aim to build.

Delivering at pace

In addition to helping to build the benefits, our industry has a crucial role to play in enhancing our approach, giving private investors the certainty they seek when committing capital. By speeding up the adoption of technology, embracing new construction techniques and encouraging collaborative models, we can reduce delivery timelines, minimise disruption, and create more attractive investment propositions.

East West Rail, a transformative project connecting Oxford and Cambridge communities, demonstrates what can be achieved with the convergence of these innovative approaches. Through an alliance model, an emphasis on integrated digital staging and modern methods of construction we delivered ahead of time, under budget. At the Bletchley Flyover, we saved £70 million through reduced disruption and brought forward the programme by six months. Similarly, advanced digital design and a new collaborative delivery partnership model for the A19 widening scheme enabled the £63.7 million project to be delivered four months ahead of schedule and under budget.

As an industry, we can only deliver on these techniques, secure the digital skills and develop the technology required when we have the confidence to invest and retain the capabilities needed. A dependable project pipeline not subject to booms and busts would provide the necessary stability. Although publicly funded, East West Rail and the A19 exemplify how collaboration and innovation can create conditions where private investment has greater confidence.

Ambition to action

The next few months are critical for the UK transport sector, with the forthcoming Comprehensive Spending Review serving as a telling indicator. Despite welcome reforms, ambition must convert into action, which attracts significant private finance and builds supply chain confidence while delivering for communities.

End-to-end integrators who straddle funding and delivery can be the thread that knits together the interests of the public, the client and investors. These organisations can ensure that a programme’s benefits are delivered in an effective manner, from its early phases and construction through to operations and maintenance.

Today’s transformative projects, from the Elizabeth Line to the Liverpool-Manchester Railway Board’s plans, echo the Victoria Line’s legacy. By embracing holistic assessments which recognise the true value of transport schemes’ economic and social impacts, the UK can unlock new regional connectivity and urban regeneration.

Developing the right conditions for private investment in transport – a guiding playbook, well-equipped devolved powers and innovative delivery approaches – will foster public-private collaboration to deliver the place-making infrastructure that the UK desperately needs.

This article was originally published in Civil Service World in April 2025.