Investigating the Effect of Drivers’ Body Motion on Traffic Safety

Although significant advances have been done with respect to vehicle technology and roadway construction, driver behaviour remains the number one contributing factor of traffic crashes worldwide. Studies show that one of the major causes of crashes is driver inattention. Driver inattention may occur when drivers are involved with secondary activities (e.g., texting, talking on the phone, or eating), and when they fail to follow the cues of the surrounding environment while driving. The latter is particularly important when drivers are negotiating maneuvres and are required to interact with other vehicles as in the case of changing lanes or merging onto the freeway. The main objective of this research is to investigate the relationship between driver behavior and safety, by looking at the actual body movements and posture, as well as the eye fixation of the drivers when they are performing lane changing and merging maneuvers under different traffic conditions. To accomplish this objective, a total of 35 drivers were recruited to participate in an instrumented vehicle field study, where each participant drove for approximately two hours along a pre-selected route. Participants’ 3D body posture was recorded with the use of a low-cost infrared depth sensor (Microsoft Kinect). In addition, participants’ eye gaze throughout the entire data collection effort was recorded with the help of eye-tracking equipment. Lastly, the vehicle was equipped with two cameras that faced the front and the rear which allowed for information about the traffic conditions during the data collection period to be obtained. A rich dataset of driver behavior was developed and analyzed as part of this research. The analysis findings relate the 3D sequence of driver motion and posture with the actual eye and head movement of drivers. Based on the analysis, head movements were the predominant type of movement when driving. The average duration of head movements was 4 seconds and 3.75 seconds for freeway merging and lane changing maneuvers respectively, and 2.3 seconds for arterial lane changing. Analysis of the magnitude of movements while driving showed that the right arm was more active than the left arm for the majority of the drivers, and differences between different driver groups were observed. However, given the small sample available in this study, the findings should be treated with caution. This report presents the research approach, summarizes findings, and provides recommendations accordingly. The research approach is useful for establishing guidelines for monitoring driver behavior as part of advanced driver assistance systems. The proposed framework has also potential in developing appropriate alert mechanisms for increasing driver alertness by monitoring driver body posture.