1. Department of Geosciences, University of Arkansas, Fayetteville, AR, USA
2. Department of Environmental Sciences, Emory University, Atlanta, GA, USA
3. School of Earth and Environmental Sciences, University of Queensland, Brisbane, Australia
4. College of Environmental Design, University of California, Berkeley, CA, USA
5. Transport Studies Unit, University of Oxford, Oxford, UK
6. Department of Geography, University of Utah, Salt Lake City, UT, USA
7. Department of Geography and Urban Studies, Temple University, Philadelphia, PA, USA
8. Department of Computer Science, University of Nevada, Las Vegas, NV, USA