Guidelines for ecological compensation associated with highways

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 prop oses guidelines for its implementation in the context of highway developmen t. To this end, a coherent framework has been developed comprising: (1) imp acts on nature, (2) concepts for use in planning ecological compensation, a nd (3) ecological, spatial-planning and financial instruments for realizing such compensation. Finally, the Dutch experience is discussed within the i nternational context. Recommendations are made for improving the implementa tion of compensation. These stress the importance of creating 'win-win' sit uations to increase public support, of dealing with impacts that cannot be predicted, and of developing criteria for evaluating compensation plans. Th ere are still several priority problems to be dealt with: the effects of ha bitat isolation caused by highway projects, the effectiveness of compensati on measures and compensation ratios (viz. ratios of replacement to lost are a) greater than one, the real costs associated with replacing habitats, the feasibility of compensation for ecological values that are difficult to re place, and the strategy to exchange impacted and substitute habitats. (C) 1 999 Elsevier Science Ltd. All rights reserved.