Guidelines for ecological compensation associated with highways

Abstract Avoidance, mitigation and compensation are three planning concepts designed to counteract the adverse impacts of infrastructure on nature. To promote the compensation principle introduced in the Netherlands, this article proposes guidelines for its implementation in the context of highway development. To this end, a coherent framework has been developed comprising: (1) impacts on nature, (2) concepts for use in planning ecological compensation, and (3) ecological, spatial-planning and financial instruments for realizing such compensation. Finally, the Dutch experience is discussed within the international context. Recommendations are made for improving the implementation of compensation. These stress the importance of creating ‘win–win’ situations to increase public support, of dealing with impacts that cannot be predicted, and of developing criteria for evaluating compensation plans. There are still several priority problems to be dealt with: the effects of habitat isolation caused by highway projects, the effectiveness of compensation measures and compensation ratios (viz. ratios of replacement to lost area) greater than one, the real costs associated with replacing habitats, the feasibility of compensation for ecological values that are difficult to replace, and the strategy to exchange impacted and substitute habitats.