1. Department of Business and Politics, Copenhagen Business School, DK-2000 Frederiksberg, Denmark;
2. Energy, Transport and Climate Policy Research Group, Wuppertal Institute for Climate, Environment and Energy, 10178 Berlin, Germany;
3. Institute of Transportation Studies, University of California, Davis, California 95616;
4. Logistics Department, Kühne Logistics University, 20457 Hamburg, Germany;
5. Transportation Research and Injury Prevention Programme, Indian Institute of Technology Delhi, New Delhi 110 016, India;