Edinburgh tram (Hardie inquiry)

The Edinburgh Trams project was initially intended to be a three-line network costing £375 million. By the time the first (and only) shortened line opened in 2014, the cost had hit £776 million (later revised by the inquiry to £835.7 million), and the city had endured years of disruptive construction and a high-profile legal battle with the contractor, Bilfinger.

Lord Hardie’s 961-page report identified ten "headline causes" of failure. He singled out Transport Initiatives Edinburgh (TIE), the arms-length company set up to run the project, for "principal responsibility." He found that TIE had failed to work collaboratively, provided misleading reports to councillors, and failed to follow "optimism bias" guidelines—meaning they consistently underestimated costs and risks to make the project seem more attractive.

The report also criticised the Scottish Government for "an abdication of responsibility." After a political vote forced the SNP minority government to fund the project they opposed, they withdrew Transport Scotland (the national agency) from a direct management role, leaving the project in the hands of a council that lacked the technical expertise to manage it. Lord Hardie noted that this "lost the chance" for professional oversight that could have reined in TIE's mismanagement.

Perhaps the most controversial aspect of the inquiry was its own duration. Lasting longer than the Chilcot Inquiry into the Iraq War, it cost taxpayers over £13 million. Lord Hardie defended the length by pointing to the "literally millions of documents" (over 6 million) that had to be reviewed and the complexity of the "irreparably flawed" contract at the heart of the dispute. The report's legacy is a recommendation for new legislation to allow criminal sanctions against officials who knowingly provide false information to councillors about major public projects.