Post Completion Analysis for Infrastructure Projects

Lead agency


Enduring question 3.2

What are the planned and actual costs and benefits involved in infrastructure projects?

Gap addressed

Limited information on the accuracy of cost-benefit analysis (CBA) predictions and whether projects fulfil their objectives.


Governments at all levels make infrastructure spending decisions based on CBAs. CBAs are a rigorous, transparent, quantitative method that measures the degree to which individual projects generate net benefits (benefits minus costs) across Australia, and allows comparison and ranking of options and projects10. CBAs are conducted ex-ante (before construction), meaning, based on CBAs only, there is limited information on the accuracy of CBA predictions and whether projects fulfil their objectives.


Conduct more independent post completion (ex-post) evaluations of CBAs for infrastructure projects and make findings publicly available.

Project update

BITRE has undertaken two rounds of ex-post evaluations of national road investment projects: one in 2005–2007 and the other in 2014–2016. BITRE Research Report 145 synthesises the earlier ex-post evaluation results with the aim of identifying opportunities to improve future CBAs and project appraisal.

Evidence drawn from the ex-post case studies suggests there is much room for improvement in the quality of practical Australian road CBAs if they are to be used as an effective tool for option ranking and project prioritisation purposes. Key areas identified for improvement include:

  • CBA documentation
  • CBA review
  • Traffic forecasts
  • Road user benefit assessment
  • Project cost estimation

Findings of this report will inform the ongoing update of Australian Transport Assessment and Planning (ATAP) guidelines and Infrastructure Australia's Assessment Framework, which will in turn contribute to making better infrastructure investment decisions in future.

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