More traffic deaths after Sept. 11 (UPI) -- An estimated 1,600 people died in U.S. auto crashes a year after Sept. 11, 2001, because more took to driving due to their fear of flying, researchers say. Wolfgang Gaissmaier and Gerd Gigerenzer of the Harding Center for Risk Literacy at the Max Planck Institute for Human Development in Berlin said earlier studies showed following the terrorist attacks, more people chose to drive rather than fly, feeling it was safer. Twelve months following Sept. 11, 2001, there were an estimated 1,600 more accident-related deaths on American roads than would have been expected statistically, the study said. The study, scheduled to be published in the journal Psychological Science, showed car traffic increased particularly in the New York vicinity, but the traffic volume increased sharply even in some states far from New York -- especially in the Midwest, where the infrastructure was well suited to replace flying with driving. "Our study findings support the assumption that the fear created by terrorist attacks can cause potentially risky behavior," Gaissmaier said in a statement.