Although teen fatalities due to motor vehicle crashes have been declining over the past decade, they remain the leading cause of adolescent fatalities in Iowa.

The purpose of this study was to combine data from a variety of sources to create detailed case studies of each fatal crash involving a driver under the age of 20 that occurred in Iowa from 2009–2011. During the study period, there were a total of 126 crashes involving 131 teen drivers that resulted in 143 fatalities.

For each crash, HF Program researchers put together a case study that included as much information as possible on crash factors such as: time of day, type of road, type of crash (e.g., rear-end, run-off-road), type of license teen driver carried, contributing factors (e.g., weather), reporting agency, and fault/charges/litigation. Statistical analyses were conducted to examine the priority of and interrelations between these factors.

Key findings of the study include:

  • Teen drivers contributed to 74% of the crashes they were involved in
  • Crashes were most likely to occur in the late afternoon (between 2-6 pm) and in the early morning (between 12-4 am)
  • More passengers translated to higher risk of crash—in 72% of fatal crashes there were 2 or more passengers in the vehicle
  • Alcohol or drug impairment was a factor in about ¼ of all crashes
  • Driving too fast for conditions or speeding contributed to about ¼ of crashes where teens were at fault
  • Nearly two thirds (63%) of drivers involved in fatal crashes were male
  • Only half of occupants (including the driver) were wearing seat belts
  • Single vehicle run-off-road crashes were the most common type of crash
  • Rate of fatal crashes decreased as driver’s age increased

The study concluded that motivating teens to refrain from driving when impaired or riding with impaired drivers, to drive at appropriate speeds, and to buckle up every time continue to be the primary challenges to reducing teen MVC fatalities.

Younger teen drivers had higher rates of fatal crashes (based on miles driven), and most were road departures, suggesting crashes may have been due to inexperience. Encouraging families to increase the amount of driving that teens do under supervision and to restrict driving to limited, lower‐risk situations (e.g., driving only in daylight hours) when teens first drive independently may help reduce the rate of fatal crash involvements for 15, 16, and even 17year old drivers.

Finally, limiting the number of passengers these new drivers can transport could also reduce fatalities.

Research sponsored by the Iowa DOT.

UI researchers: Dan McGehee, Michelle Reyes

The HF Program has been collecting detailed crash information on every teen fatality in Iowa since 2009. These data are made up of police crash reports, medical examiner and site data, and media reports. By triangulating these crash sources, a more complete understanding of every fatal crash is gained.