This paper investigates the causes of misjudgement of infrastructure costs by distinguishing systematically various classes of miscalculations and misrepresentations of costs. A comparative analysis of cost estimates of transport infrastructure projects in the Netherlands and Finland is performed. The Dutch infrastructure projects selected are: two motorway projects, the Wijkertunnel, the Hemspoortunnel, and the Van Brienenoord bridge. The three Finnish infrastructure projects selected are main road projects. Based on that comparative analysis, the interesting conclusion is found that in general cost estimates tend to be rather reliable. Underestimations are - in addition to inflationary backgrounds caused by the delay of projects over a long time span - mainly the result of additional political wishes in the form of adjustments or extensions imposed during the preparation and implementation stage of projects and which cause excessive cost rises.
Samenvatting