The Contribution of Medical Conditions to Passenger Vehicle Crashes

There is a growing concern about risks associated with driving for people with known medical conditions. However, the association between having a chronic medical condition and being involved in a motor vehicle crash remains controversial. This analysis aims to identify crashes that have been precipitated by medical emergencies or other medical conditions while driving. This report provides a retrospective analysis of the National Motor Vehicle Crash Causation Survey (NMVCCS). NMVCCS was a nationwide survey of crashes that occurred between 6 a.m. and 12 a.m. in the period from July 3, 2005, to December 31, 2007. NMVCCS was limited to crashes involving light passenger vehicles to which emergency medical service (EMS) had been dispatched. The percentage of drivers in crashes precipitated by their medical emergencies while driving are relatively rare and account for only 1.3% of all drivers that have been included in NMVCCS. Older drivers have relatively higher incidences of crashes precipitated by drivers’ medical emergencies when compared to young and middle-age drivers. 84% of the drivers in crashes precipitated by medical emergencies experienced seizures, blackouts, or diabetic reactions prior to the crashes. Drivers or surrogate responses to questions about general health, use of medications, and feelings on the day of the crash suggest that most of the drivers were aware of the medical conditions associated with the crash. Drivers in crashes precipitated by medical emergencies were more likely than other drivers to be more severely injured or to die as a result of the crashes. An estimate of 62% of the drivers who had crashes precipitated by medical emergencies were involved in single-vehicle crashes compared to an estimate of only 17% of the other drivers. In an estimate of 85% of the drivers who had crashes precipitated by medical emergencies, the driver was the only occupant in the vehicle compared to an estimate of 69% of the other drivers. An estimated 69% of the drivers who had crashes precipitated by medical emergencies departed the roadway before the collision compared to only 17% of the other drivers. Drivers who had crashes that have been precipitated by medical emergencies were more likely to be involved in crashes during the morning hours between 6 a.m. and 11:59 a.m. when compared to other drivers. This analysis suggests that crashes precipitated by drivers’ medical emergencies are not related to vehicle design or roadway integrity as indicated by the type of crashes and manner of collisions. Patient education by health care providers on early warning signs of a health crisis, such as warning signs before seizure attacks, diabetic or hypoglycemic comas, and potential side effects of medications are recommended as the most effective countermeasure. In addition to patient education, other safety technologies such as the Drowsy Driver Warning System can help in reducing the risk of crashes precipitated by medical emergencies. As indicated in this report, in most cases of the crashes that have been precipitated by medical emergencies, the drivers departed the roadway. A lane departure prevention system can help detecting by positional information of a vehicle with respect to a lane of travel and alert drivers to correct their positioning on roadway.

  • Record URL:
  • Corporate Authors:

    National Center for Statistics and Analysis

    Mathematical Analysis Division, 1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Hanna, Refaat
  • Publication Date: 2009-11

Language

  • English

Media Info

  • Media Type: Web
  • Edition: Technical Report
  • Features: References; Tables;
  • Pagination: 20p

Subject/Index Terms

Filing Info

  • Accession Number: 01147315
  • Record Type: Publication
  • Report/Paper Numbers: HS-811 219
  • Files: HSL, TRIS, ATRI, USDOT
  • Created Date: Dec 28 2009 3:34PM