1. Bassett Research Institute Cooperstown New York
2. Mailman School of Public HealthColumbia University New York New York
3. Center for Injury Epidemiology and PreventionColumbia University New York New York
4. Columbia University College of Physicians and Surgeons New York New York
5. School of MedicineUniversity of Colorado Aurora Colorado
6. University of Michigan Transportation Research Institute Ann Arbor Michigan
7. Center for Advancing Transportation Leadership and SafetyUniversity of Michigan Ann Arbor Michigan
8. Bloomberg School of Public HealthJohns Hopkins University Baltimore Maryland