Scenario analysis and the adaptive approach: Superfluous or underused in transport infrastructure planning?

Both scenario analysis and the adaptive approach are rarely used in transport infrastructure planning, while there seems to be a clear value in using them (given the massive uncertainties on both the supply and demand sides, and owing to the fact that infrastructure is typically a `slow and inert´ component of the transport system). To assess why these techniques are rarely used, the authors carried out a study to determine whether these analytical approaches are (1) superfluous (that is, there is no great need for them in the policymaking sector) or (2) underused (that is, there appears to be a need for the approaches among policymakers, but the approaches are nevertheless not used), and why. The study focused on the Netherlands, a country where transport infrastructure investments (including their effectiveness and efficiency) have been high on the political agenda for decades.