How Can the Wider Economic Impacts of Transportation Assets Be Assessed?
Remi Martins-Tonks, Oxera Consulting Ltd, Andrew Meaney, Oxera Consulting Ltd, Phillip Horne, Port of Dover
The paper examines how different methods can be used to examine the wider economic impacts of transportation assets. It explains how the Port of Dover’s wider economic impact was analysed, then compares this approach with alternative approaches.
Wider economic impacts are an important part of the project appraisal process and can significantly improve the business case for proposed infrastructure projects. A survey of appraisals by SDG (2011) found that including these wider economic impacts added 25%, on average, to the total benefits of a given scheme, with a range of 5–56%. Moreover, in the UK, a new high-speed railway line is estimated by High Speed Two Ltd (2013) to have wider economic impacts equal to £13bn, and their inclusion in the business case increases the benefit–cost ratio of the project from 1.8 to 2.3.
This paper examines how different approaches can be used to assess wider economic impacts. In particular, the wider economic impact that the Port of Dover has on the UK economy is examined using a ‘bottom-up’ approach. This involves estimating the generalised cost for the different types of traffic that pass through the port (foot passengers, cars, coaches and freight vehicles) and comparing this figure with other ports and Eurotunnel. The output is a monetary value equal to the total sum of the time and financial cost savings that users gain from being able to travel via the Port of Dover rather than the alternatives.
This approach is compared with ‘top-down’ methodologies that use appraisal guidance such as the UK Department for Transport’s Appraisal Guidance (WebTAG). Some examples using this approach are then discussed, including European rail freight and aviation in the UK.
The paper concludes by discussing the relative advantages and disadvantages of these different approaches when assessing wider economic impacts. It therefore provides a reference that can be drawn upon when choosing an approach to examine the wider economic impacts of a proposed transportation project.
Association for European Transport