Real-World Analysis of Fatal Run-Out-of-Lane Crashes Using the National Motor Vehicle Crash Causation Survey to Assess Lane Keeping Technologies

Lane Departure Warning (LDW), Lane Centering Control (LCC) and Lane Keeping Support (LKS) are three advanced crash avoidance technologies intended to prevent vehicles from inadvertently running off the roadway or out of the lane of travel. All three systems utilize a camera based vision system to monitor the vehicle’s forward position with respect to the roadway. Depending on the level of system authority, the technology is intended to warn the driver that they are leaving the travel lane, continuously maintain the lateral position of the vehicle within the lane of travel, or redirect the lateral path of the vehicle to stay in the lane. A real-world analysis of run-out-oflane crashes where at least one of the involved vehicles’ occupants sustained fatal injuries was conducted. The study utilized the National Motor Vehicle Crash Causation Survey (NMVCCS) to better understand why drivers depart the roadway and under what conditions and circumstances the crashes occur to begin to assess the potential effectiveness of these countermeasures. NMVCCS was a nationally representative survey conducted by National Highway Traffic Safety Administration from 2005-2007. Trained researchers conducted on-scene investigations of nearly 7,000 crashes during the project, focusing on the pre-crash phase. The ability to investigate the selected crashes on-scene, in most cases within minutes, allowed the researchers to make better assessments of the events that led up to the crash. To evaluate the potential effectiveness of a vision system that monitors the position of the vehicle on the roadway, it was important to use a dataset that assessed the environmental and roadway conditions as soon as possible after the crash occurred. For each crash identified, a review of the accompanying investigation was conducted. The intent was to identify any attributes or factors that were consistent among the cases and any environmental or roadway conditions that may impact the performance of a crash avoidance countermeasure, such as poor lane markings, sensor blindness attributable to darkness, or weather conditions. This broad study identified 72 NMVCCS cases where the subject vehicle left the travel lane and resulted in a crash where an occupant in an involved vehicle sustained fatal injuries. Specifically , 43 cases were identified where the subject vehicle drifted out of the lane, resulted in a crash, and was relevant to assessing the realworld applicability of LDW/LCC/LKS crash avoidance technologies. This study found that a robust LKS/LCC should make it more difficult for the driver to drift out of their lane. With sufficient lateral control authority, an LKS/LCC system could have effectively prevented many of the 43 cases reviewed in this study. In other words, unless there were other factors present which prevent the driver from reengaging in the driving task, a robust LKS/LCC would likely have prevented the driver from running out of the lane, which started the chain of events that led to the fatal crashes. LKS/LCC appears to have more potential in crash reduction than LDW since the system does not rely on alert modality effectiveness or the driver tak ing corrective action. Lastly, environmental and roadway conditions at the time of the crash would likely not have compromised the performance of the vision system to detect the roadway boundary at the moment the vehicle left the lane .