The Effect of Cell Phone Bans on Driver Behavior , Accidents , and Casualties

In response to concerns that distracted driving due to cell phone use has become a threat to roadway safety, many states have passed cell phone bans that prohibit drivers from texting and talking on handheld cell phones. This paper empirically examines the impact of these bans on driver cell phone usage, traffic accidents, and casualties. To distinguish the effect of the bans from confounding factors, I use a difference-in-differences approach that exploits the within-state variation in the adoption of cell phone bans. Results indicate that prohibiting drivers from texting and talking on handheld cell phones reduces drivers’ handheld device manipulation and cell phone use by 60 and 40 percent, respectively. This effect is largely driven by adult drivers and drivers with passengers. However, cell phone bans do not appear to have any meaningful impact on accidents and casualties. Several robustness and falsification exercises, including permutation tests using placebo ban estimates, are used to test the validity of both the estimates and their statistical significance. _________________ † Cheng Cheng: Texas A&M University, Department of Economics, 3050 Allen Building, 4228 TAMU, College Station, Texas 77843 (Email: ccheng@econ.tamu.edu). I thank Mark Hoekstra, Christopher Carpenter, Scott Adams, Daniel Hamermesh, Jonathan Meer and Jeremy West for helpful comments and suggestions. I also thank Timothy Pickrell of the National Highway Traffic Safety Administration for providing raw data of the National Occupant Protection Use Survey.