The OECD Recommendation on the Governance of Infrastructure emphasises the importance of systematic collection, storage and management of relevant data on the whole infrastructure life cycle at appropriate government levels (central or subnational). Evidence-informed decision making is crucial for delivering quality infrastructure and effectively and efficiently managing assets that are resilient to risks, such as climate-related risks. A strategic approach to evidence enhances the understanding of infrastructure trends and needs, improving long-term planning for investments and development. An evidence-based approach also increases the resilience of assets and enhances accountability and transparency in decision making across the life cycle of infrastructure projects.
Such evidence-informed decision making uses existing evidence and past analyses to generate new insights into the costs, benefits and effects of infrastructure projects, guiding future decisions. Most OECD countries with available data (28 out of 31, 90%) use cost-benefit analysis to appraise and select public-private partnerships (PPPs) or other infrastructure projects. These offer a simple logic, and generate clear quantitative values (i.e. net present values, benefit/cost ratios) that can be used to compare and rank projects. Methodologies such as multi-criteria analysis which can accommodate longer-term goals – such as environmental sustainability – are less widely used (18 out of 31, 58%) (Figure 10.8).
The OECD Infrastructure Governance Indicator (IGI) index on evidence-informed decision making gives an overview of the use of evidence in the transport sector during the strategic planning, project appraisal and impact analysis, procurement, and infrastructure management stages of projects. The average score across OECD countries is 0.65 out of a maximum of 1, with country scores ranging widely from 0.14 to 1 (Figure 10.9). Evidence is most widely used during project appraisal and impact analysis, while the most room for improvement is in its use during the procurement process.
Almost all OECD countries (29 out of 30 with available data, 97%) use ex ante analysis of past trends in infrastructure use in order to project needs. Most countries (26 out of 30, 87%) also assess the risks of systematic service disruptions, such as local or national disasters, to inform contingency planning. However, systematic and comprehensive ex post analysis is less common. Such analysis can be used to assess plans, project selection and delivery, and performance during operation. Many countries require ex post evaluation of transport projects, however, few actually enforce this requirement (ITF, 2017). This failure is often related to a lack of dedicated funding for ex post evaluation and limited availability of relevant data. For example, just over half of OECD countries (15 out of 29 with available data, 52%) use ex post analysis of previous transport master plans to inform current plans (Figure 10.10). The same number conduct systematic ex post analyses of contract performance, such as cost overruns and delays. However, only 13 (45%) use these analyses to inform future procurements (see Online Figure J.7.3). For successful ex post evaluation, it is recommended to, among other things, plan for data collection for evaluation needs from the outset and audit projects throughout the life cycle (ITF, 2017).
