1. Copernicus Institute of Sustainable Development, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, The Netherlands
2. Grontmij, Division Transport and Mobility, P.O. Box 203, 3730 AE De Bilt, The Netherlands
3. Centre for Environmental Law and Policy, Utrecht University, Achter Sint Pieter 200, 3512 HT Utrecht, The Netherlands