Roadside evaluation of distracted driving – Driver limitations in recognizing traffic light transitions (REDD – LIGHT)

Abstract Introduction Distracted driving is dangerous, widespread and has become one of the top concerns regarding traffic safety. The goals of the REDD – LIGHT study were to naturalistically determine the prevalence of distracted drivers at a red traffic light, as well as to determine the prevalence of specific distractions and their impact on the drivers’ reaction to traffic light transition. Methods We observed the drivers of the first two passenger motor vehicles stopped at a red traffic light. The observational variables were divided into three general groups: demographic variables, distractions (in-vehicle, outer-vehicle, and mobile phones), and reaction to traffic light transition. Vehicles falling behind the full length of a car or failing to proceed for more than 2 s at the traffic light transition from red to green were classified as delayed. Results Of the 1008 drivers in this study, 608 (60.3%) were observed to be distracted at the red light. In-vehicle distractions were the most common type of distraction (44.8%, n=452), while mobile phone-related distractions were 7.4% (n=75). A total of 126 (12.5%) drivers were delayed at the light transition, and 111 (88.1%) of these drivers were distracted. We identified seven specific distractions (talking on a handheld device, manipulating a handheld device, in-vehicle devices, eating/drinking, reaching, non-specific and specific outer-vehicle distractions) as significantly associated with the delay to the light transition. Conclusion Three out of five drivers engaged in distracted driving when stopped at a traffic light. In addition, approximately nine out of ten delayed drivers were distracted, clearly demonstrating the negative effects of distractions on the driver's situational awareness. These figures are astonishingly high and massively concerning, considering that the data was acquired from a single red light stop along the driver's trip.