Consequences for road traffic fatalities of the reduction in flying following September 11, 2001

Gigerenzer [Gigerenzer, G. (2004). Dread risk, September 11, and fatal traffic accidents. Psychological Science, 15, 286–287] argued that the increased fear of flying in the U.S. after September 11 resulted in a partial shift from flying to driving on rural interstate highways, with a consequent increase of 353 road traffic fatalities for October through December 2001. We reevaluated the consequences of September 11 by utilizing the trends in road traffic fatalities from 2000 to 2001 for January through August. We also examined which road types and traffic participants contributed most to the increased road fatalities. We conclude that (1) the partial modal shift after September 11 resulted in 1018 additional road fatalities for the three months in question, which is substantially more than estimated by Gigerenzer, (2) the major part of the increased toll occurred on local roads, arguing against a simple modal shift from flying to driving to the same destinations, (3) driver fatalities did not increase more than in proportion to passenger fatalities, and (4) pedestrians and bicyclists bore a disproportionate share of the increased fatalities.