Inclusion Criteria Included were subjects who completed the questionnaire, who had driven a motor vehicle 1000 miles yearly and who provided information about accident history. Exclusion Criteria We excluded subjects who did not complete the questionnaire, who had driven a motor vehicle less then 1000 miles yearly, or who did not provide information about accident history. All data were transferred immediately via an internet link to an SAS Institute (Cary, NC) statistical program to be analyzed. Extracted from this large database were demographics and data specifically associated with sleepy driving behaviors