Update Optimism Bias Guidance
Edinburgh Tram Inquiry · Edinburgh Tram Inquiry Report · Issued 12 September 2023 · Addressed to: Scottish Government
Source — verbatim from the inquiry
●Inquiry recommendation
Optimism bias guidance, based on decades-old data, requires updating to include light rail projects and reflect current empirical evidence, with reviews every five years.
Edinburgh Tram Inquiry, Edinburgh Tram Inquiry Report · 12 Sep 2023 Source PDF →
Published evidence summary
Publicly available evidence relating to this recommendation:
- No published update to optimism bias guidance incorporating light rail project data or reflecting current empirical evidence has been identified to March 2026.
Sources
Response — verbatim from government
●Scottish Government
The Scottish Government stated it already operates in line with best practices but will consider updating guidance. Source: Transport Secretary Statement, 2 November 2023.
Scottish Government · 2 Nov 2023 Written response →
Evidence trail — what's actually happened since
- 2 Nov 2023 Initial status based on Scottish Government and City of Edinburgh Council responses to the Edinburgh Tram Inquiry Report (September 2023). Source →
Each entry above links to a primary source — gov.uk written statement, consultation response document, or inspection report. The Index does not characterise government intent; it tracks what has been published.
How this page is built
Source and Response are verbatim from primary documents. The Evidence trail records published activity since — written statements, consultation outcomes, inspection findings, parliamentary references. The Index does not paraphrase or characterise intent; it tracks what has been published. Where the evidence is the absence of action (a missed deadline, a slipped timetable), that absence is documented from primary sources rather than inferred.
This recommendation's data is verified periodically against primary sources. The Index is monitored for staleness weekly.