1. Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC 27695-7908.
2. Institute for Transportation Research and Education, North Carolina State University, Raleigh, NC 27695-8601.
3. Highway Safety Research Center, University of North Carolina, Chapel Hill, NC 27514.
4. Toole Design Group, 4603 Calvert Road, College Park, MD 20740.
5. Department of Statistics, North Carolina State University, Raleigh, NC 27695-8203.
6. Office of Safety Research and Development, Turner–Fairbank Highway Research Center, FHWA, McLean, VA 22101.