1. Using NHTS Data as a Measure of Exposure Data Meg Sweeney* Lee Giesbrecht Jonaki Bose Bureau of Transportation Statistics This work was completed while Meg Sweeney was employed at the Bureau of Transportation Statistics

2. Accident Rate Accident Measure Number of Fatal Accidents Number of Large Truck Accidents Number of Injuries Exposure Measure Number of Registered Vehicles Number of Licensed Drivers

3. Number of Fatal, Single-Vehicle Crashes per 100,000 Registered Vehicles, 2001 Sources: Subramanian, R. (2004). Analysis of crashes involving 15-passenger vans (NHTSA Technical Report DOT HS 809 735.). Washington, DC; Mathematical Analysis Division, National Center for Statistics and Analysis, National Highway Traffic Safety Administration. NCSA, NHTSA, FARS 1990-2002 (Final), 2002 (ARF) Files and R.L. Polk and Company NVPP Registration Data

4. Vehicle Involvement Rate in Fatal Crashes per 100,000 Registered 15-Passenger Vans in the U.S., 1990-2001 Sources: Subramanian, R. (2004). Analysis of crashes involving 15-passenger vans (NHTSA Technical Report DOT HS 809 735.). Washington, DC; Mathematical Analysis Division, National Center for Statistics and Analysis, National Highway Traffic Safety Administration. R.L. Polk & Co., National Vehicle Population Profile (NVPP), 1990-2002 and NCSA, NHTSA, FARS 1990-2002 (Final), 2002 (ARF) Data.

5. Need for Additional Exposure Data Time of Day Driver Age National Household Travel Survey

6. Computer assisted telephone interview Collected April 2001 to May 2002 Includes demographic information on households, people, and vehicles Detailed information on daily and long distance travel

7. NHTS Exposure Measure Estimated number of drivers on the road during a given hour Daily travel data Weighted estimates

8. Drivers on the road (NHTS)

9. Accident Rate Number of drivers involved in fatal (FARS) or fatal, injury, or property damage (GES) accidents in a given hour Estimated number of drivers on the roadway during that hour

10. Fatality Analysis Reporting System (FARS) Census of all highway accidents Death of an occupant of a vehicle or nonmotorist within 30 days of crash Motor vehicle traveling on trafficway customarily open to public Information on the crash, vehicles and people involved

11. Fatal accident involvement (FARS)

12. General Estimates System (GES) Nationally representative probability sample selected from all-police reported crashes To be eligible for selection: –Completed PAR –Involve at least one motor vehicle traveling on trafficway –Result in property damage, injury, or death Information on crash, drivers, and vehicles Weighted data

13. Injury, Property, and Fatal Accident Involvement (GES)

14. FARS and GES Analysis Drivers of passenger cars and motorcycles Aged 15 years and older April 2001 to May 2002 Accident types: –Total accidents –Fatigue-related accidents –Failure to yield accidents –Alcohol-related accidents

15. Fatal Accidents

16. Fatal Fatigue-related Accidents

17. Fatal Alcohol-related Accidents

18. Fatal Failure to Yield Accidents

19. Accident Involvement (GES)

20. Failure to Yield Accident Involvement (GES)

21. Accident Rate Comparison (FARS)

22. Fatigue-related Accident Rates

23. Alcohol-related Accident Rates

24. Failure to yield Accident Rates

25. Exposure by time of day and Age

26. Fatal Accidents by Time of Day and Age

27. Rate of accident involvement by age and time of day

28. Fatal Fatigue Accidents by Time of Day and Age

29. Rate of fatigue accidents by age and time of day

30. Summary Calculated rates using NHTS data as a measure of exposure The patterns of the accident rates show a peak in the early morning hours Rates reveal different patterns from number of drivers involved in accidents Patterns of rates for FARS and GES data may not be the same Exposure information shows differences by age Refinement of the exposure measure