Reforming the appraisal of publicly funded infrastructure Bradshaw Advisory and the Railway Industry Association (RIA) convened senior figures from industry, finance and government to examine one of the most technical yet influential levers of public policy: how the UK appraises infrastructure investment. Though often overlooked, the Green Book determines what the state builds, where and why. Participants agreed that reform is necessary, and while the recent review was broadly welcomed, they stressed that lasting success will depend as much on political courage, institutional reform and cultural change as on the revised guidance itself. Key themes of the discussion
1.
Over-reliance on BCRs
Participants agreed that benefit-cost ratios (BCRs) continue to dominate decision-making even when they fail to capture strategic or regional value. While some argued that BCRs accurately reflect economic gravity, most saw their dominance as a brake on regional ambition. One combined authority representative cited a northern transport project expected to deliver five times more economic growth than competing schemes, but its wider benefits could not be captured within a conventional BCR and it was therefore not approved. The 2025 Green Book review identified this over-reliance as a major weakness in the appraisal process. It confirmed that the Treasury will update the guidance to make clear that there are no fixed BCR thresholds and that a ratio below one does not automatically indicate poor value for money. Contributors from the defence sector were particularly supportive of this shift, noting that many defence programmes, by their nature, cannot demonstrate conventional value for money through BCRs alone. This reflects a broader recognition of the need to give greater weight to the strategic case within business cases, ensuring that projects with long-term or national importance are not disadvantaged by narrow economic measures. While participants welcomed the recognition of this issue, they remained concerned about how this will actually work in practice - specifically, how projects with mixed economic and strategic evidence will be compared under the new framework. 2.
Acknowledge the politics
Participants agreed that the Green Book cannot and should not seek to insulate investment decisions from politics. Appraisal operates within a politically charged environment, not in a vacuum, and reform must reflect that reality. Two dimensions of this emerged clearly from the discussion. First, the volatility of reform itself. A government eager to show quick results risks criticism if early projects are later judged poor value for money. Any move away from established metrics will attract