1Transportation Research Institute, University of Michigan, Ann Arbor, MI, U.S.A.
2Center for Research on Long Term Mental Health, Department of Veterans Affairs Medical Center, Ann Arbor, MI, U.S.A.
3Section of Emergency Medicine, University of Michigan, Ann Arbor, MI, U.S.A.
4Alcohol Research Center, University of Michigan, Ann Arbor, MI, U.S.A.