"The Impact of September 11 on Road Fatalities: The Other Lives Lost to Terrorism," with Vrinda Kadiyali and Daniel H. Simon CALS Impact Statement uri icon


  • We show that the public's response to terrorist threats can have unintended consequences that rival the attacks themselves in severity. Driving fatalities increased significantly after the September 11, 2001 terrorist attacks, events that prompted many travelers to substitute road transportation for safer air transportation. After controlling for time trends, weather, road conditions, and other factors, we find that travelers' response to the attacks resulted in 344 driving deaths per month in late 2001. Moreover, while the effect of the attacks weakened over time, a total of about 2,170 driving deaths may be attributable to the attacks.