Driver Distraction: A Review of the Current State-of-Knowledge

Distinct from other forms of driver inattention, distraction occurs when a driver’s attention is diverted away from driving by a secondary task that requires focusing on an object, event, or person not related to the driving task. Although existing data are inadequate and not representative of the driving population, it is estimated that drivers engage in potentially distracting secondary tasks approximately 30% of the time their vehicles are in motion. Conversation with passengers is the most frequent secondary task followed by eating, smoking, manipulating controls, reaching inside the vehicle, and cell phone use. Driver attention status is unknown for a large percentage of crash-involved drivers in the Crashworthiness Data System (CDS). However, for the period between 1995 and 2003 it is estimated that 10.5% of crash-involved drivers were distracted at the time of their crash involvement. Approximately 70% of distracted drivers’ crashes were either non-collision (single-vehicle) or rear end collisions. A significant proportion of the existing literature is devoted to assessing the impact of cell phone use on driving performance and safety. Although cell phone use represents a relatively small part of the overall distraction problem, use among drivers is steadily growing with approximately 10% of drivers using some type of cell phone at any point in time. Although not representative of the U.S. experience, the available evidence suggests that cell phone use increases drivers’ crash risk by a factor of 4. Experimental studies consistently reveal driving performance degradation (primarily slowed response time) associated with cell phone use; however, phone tasks used in these studies are generally unrealistic and often more complex than everyday phone conversations. Insufficient data exist to assess the distraction effects of in-vehicle information systems (IVIS), however, experimental results suggest that voice-based interfaces are less distracting than those requiring manual entry (e.g., via keyboard). Standard behavioral countermeasures, including laws, enforcement, and sanctions, are considered unlikely to be effective because distraction is a broad societal problem associated with lifestyle patterns and choices. Options for environmental (roadway) strategies are limited. Considerable activity has been devoted to the development of guidelines for IVIS interface design, resulting in some improvements. Promising future developments include large-scale naturalistic data collections to provide objective and representative data on distraction incidence and crash risk, and advanced driver assistance technologies that monitor drivers’ visual behavior and manage the flow of information to the driver. Recommendations for future research are presented.


  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: References;
  • Pagination: 32p

Subject/Index Terms

Filing Info

  • Accession Number: 01108422
  • Record Type: Publication
  • Report/Paper Numbers: HS-810 787
  • Files: HSL, TRIS, USDOT
  • Created Date: Aug 11 2008 4:15PM