Public-Private Partnerships in Question: Is Re-nationalisation the Only Answer to the Overhaul of UK Public Transport?

This policy essay argues that re-nationalisation of transport in the United Kingdom (UK), exemplified by the formation of Great British Railways, does not alone guarantee the success of infrastructure delivery. Drawing on dimensions of contractual formality and relational engagement with the private sector, we offer a four-quadrant framework for policymakers to better evaluate, implement, and manage Public Private Partnerships (PPPs) given their inevitable existence. This framework is applied to two prominent transport projects that were initially operated under private-sector arrangements, but were subsequently taken over by the public sector. Implications from the two cases are clear: (1) For policymakers: use the four-quadrant model to assess PPP proposals before approval; (2) For government departments: invest in relational capacity-building alongside contractual oversight; and (3) For regulators: monitor trust and transparency indicators in PPPs, not just financial metrics.