Since privatisation in the 1990s, cash flows in the rail system have become increasingly complex. Although the rail system is privatised, government still provides significant funding for infrastructure operations, maintenance and renewals, and ongoing subsidy for passenger service operations. The National Audit office’s report identifies that the lack of a complete set of public data makes it difficult for Parliament and taxpayers to understand the overall financial position of the rail system, and the impact of government’s choices.30 The lack of whole-system financial data adds to poor financial transparency in the rail system. During the session, the Office of Road and Rail told us about its oversight of Network Rail, which demonstrated to us the importance of data in enabling effective monitoring and progress reporting.31