Driver Inattention , Driver Distraction and Traffic Crashes

ITE JOURNAL / JULY 2003 INTRODUCTION The National Highway Traffic Safety Administration (NHTSA) has estimated that driver inattention is a causative factor in 25–30 percent of police-reported traffic crashes in the United States— approximately 1.2 million crashes per year.1,2 An inattentive driver may be distracted temporarily from the driving task by something inside or outside the vehicle, may be “lost in thought” or otherwise cognitively removed from the driving task, or may be fatigued or drowsy. While this is not a new phenomenon, there is evidence that driver inattention may be a growing highway safety problem. According to the National Sleep Foundation, the number of shift workers in the United States increases by 3 percent per year, and these workers face an increased risk of involvement in sleeprelated crashes.3 In addition, the recent proliferation of cellular telephones is only a prelude to the array of wireless technologies that soon will be available in vehicles. NHTSA has expressed concern about the negative effects of these new technologies on driving safety. In summer 2000, NHTSA hosted an Internet forum on the safety implications of cellular telephones, vehicle navigation systems, wireless Internet capabilities, wireless messaging and other in-vehicle technologies.4 Technical experts as well as the general public contributed to the forum, which drew widespread national and international participation. In May 2001, the U.S. Congress scheduled hearings before a House subcommittee on the topic of driver distractions and the use of electronic devices in vehicles. NHTSA Executive Director L. Robert Shelton spoke at the hearing.5 In 2002, the National Conference of State Legislators released a report documenting an eight-month study that brought together state legislators and staff; wireless service providers; auto manufacturers; other interested companies and industries; safety groups; federal agencies; researchers; and other stakeholders to address the issue of technology in motor vehicles and its potential to distract drivers.6 The American Automobile Association Foundation for Traffic Safety also has shown concern. In 1999, it funded a three-year study, entitled “The Role of Driver Distraction in Traffic Crashes.” The study was carried out in two phases. The first phase involved the analysis of five years of data from the national Crashworthiness Data System (CDS), to determine the role of driver distraction in U.S. traffic crashes and identify specific sources of distraction.7 The second phase involved the collection of naturalistic driving data, to document drivers’ exposure to specific distracting events and the effects of these events on driving performance.8 This feature briefly summarizes the results of the study.