Cumulative effects: treatment in Strategic Environmental Assessment and Environmental Impact Assessment of roads

In Swedish transport infrastructure planning, cumulative effects are not given the attention demanded by the Swedish Environmental Code and the European so-called SEA and EIA directives (Strategic Environmental Assessment and Environmental Impact Assessment, respectively). In the Environmental Code, the formulations concerning cumulative effects are vague. The EIA handbook of the Swedish Road Administration does not give much guidance. There is thus a great need for development of procedures and methods adapted to Swedish road planning. The overall aim of the report is to contribute to the development of the treatment of cumulative effects in SEA and EIA of road planning in Sweden. Specific aims are to describe the concept of cumulative effects and to give advice on approaches and methods that can be used in cumulative effects analysis and assessment. The report mainly builds on American and Canadian literature. "Cumulative effects" are changes to the environment that are caused by an action or measure together with other past, present and future actions and measures.