Scenario planning for transport practitioners

Scenario planning helps in contemplating how the future may develop and can be especially important when needing to make sense of uncertainty - something now pertinent to the transport sector. Accordingly, scenario planning is moving from the periphery of strategic transport planning towards becoming a more normalised and integral contribution. By examining rather than ignoring a range of uncertainties about the future, scenarios can be developed that enable an exploration of different futures, in turn improving transport planning. Scenarios can be narrative based, represented quantitatively, or combine 'storytelling and number crunching'. Both the process of creating them and of representing the scenarios, deepen an appreciation of uncertainty about the future. In turn this allows planners and policymakers to better understand potential outcomes and challenges and determine how to address these. Scenarios can also be used to identify and assess candidate measures for influencing the transport system, testing these against a range of uncertain future conditions. This helps to identify measures that together can help form a strategy that is more robust. Drawing upon the combined experience of its authors, this paper provides insights into the development of scenarios and their use to improve decision making in transport planning. It offers advice on how to help ensure the scenario development process is credible, how to produce a coherent set of scenarios and how to ensure they are used to engage key stakeholders and to enable policymakers to confidently develop their strategic thinking and plans.