In the last decade there has been an increased focus on socio-economic impact assessments of significant infrastructure projects in the road sec-tor. Further, environmental impacts assessment (EIA) is constantly being demanded, due to the increased debate about the environmental impact of road traffic. This has in turn increased the requirements placed on the socio-economic assessment methods. The socio-economic assessment is intended to provide a comprehensive evaluation of a given project's profitability; however, there are always con-siderable uncertainties associated with such analyses. It is therefore important that the focus of investigation encompasses more than mere numbers such as net present values or internal rate of return. Further, it is crucial that the analysis also identifies the critical factors for the outcome of the evaluation of profitability. Another important aspect of a good socio-economic assessment is that it must provide a systematic and transparent accounting of the project's benefits and costs, thereby contributing to openness in the decision-making process. The report presents an updated state-of the art in terms of socio-economic assessment of transport infrastructure projects for the Nordic countries: Finland, Norway, Sweden and Denmark. The present report is based on Danish Ministry of Transport (2002). The following themes are examined: 1. Organization (institutions, etc.), 2. Economic principles, that serve as the basis 3. Type of costs and benefits included 4. Process for conducting the analyses 5. Dissemination of the results