Motorway expansion: a must, or superfluous?

A review of the use of economic scenarios for doing the sums on MIRT projects

The scenarios and traffic projections on which investments in the Dutch national road grid are based are outdated and lead to inefficient investments. Current transportation demand is lower than in the lowest scenarios used for doing the relevant sums. Today’s decisions on motorway expansion are based on the ‘high-end’ scenario, and as a result investments erroneously appear to have a positive economic impact.

Conservation and environmental NGOs asked CE Delft to examined the validity of the scenarios currently used for calculating traffic volumes. Based on a literature study and interviews with experts (including professors and researchers) an analysis was made of the Multi-Year Programme for Infrastructure and Transport (MIRT), the traffic volume models employed and the underlying scenarios for the future. For six motorway projects the assumptions behind the social cost-benefit analyses (SCBAs) were also analysed.

The scenarios employed are outdated
The SCBAs of motorway projects conducted in recent years have all been based on the WLO scenarios (‘Prosperity and Living Environment scenarios’) for 2006 or in some cases even earlier. A comparison of these scenarios with recent developments shows that since 2009 the traffic volume on the national road grid has been consistently below the lowest WLO scenario (the ‘Regional Communities’ scenario). Reasons include sluggish economic growth and an oil price three times higher than in the WLO scenarios. Potential saturation of private car use and the emergence of teleworking may also be involved.

ERRATUM
The second paragraph of Section 5.3.2 makes reference to a second opinion. This second opinion did not relate to the SCBA of the project in question, however, but to a financial analysis of potential toll concepts. In this second opinion scenarios are not explicitly mentioned, but reference is made to uncertainties relating to traffic projections.

Motorway expansion: a must, or superfluous?

Authors CE

Maarten 't Hoen
Huib van Essen

Delft, November 2013