Do Drivers Pay Attention During Highway-Based Automated Lane Changes While Operating under Hands-Free Partially Automated Driving?

This study assessed a driver’s ability to safely manage Super Cruise lane changes, both driver commanded (Lane Change on Demand, LCoD) and system triggered Automatic Lane Changes (ALC). Data was gathered under naturalistic conditions on public roads in the Washington, D.C. area with 12 drivers each of whom were provided with a Super Cruise equipped study vehicle over a 10-day exposure period. Drivers were shown how to operate Super Cruise (e.g., system displays, how to activate and disengage, etc.) and provided opportunities to initiate and experience commanded lane changes (LCoD), including how to override the system. Overall, drivers experienced 698 attempted Super Cruise lane changes, 510 Automatic and 188 commanded LCoD lane changes with drivers experiencing an average of 43 Automatic lane changes and 16 LCoD lane changes. Analyses characterized driver interactions during LCoD and ALC maneuvers exploring the extent to which drivers actively monitor the process and remain engaged and alert relative to manually executed lane changes (e.g., mirror checks, interventions, etc.). Results found evidence to suggest that drivers remain vigilant during Super Cruise automated lane changes, both when driver commanded LCOD (LCoD) and when executed automatically. Further, search behavior persisted over time and with experience; drivers were observed to search mirrors or make direct Over-the-Shoulder glances for nearly all executed lane changes, both under Super Cruise or Manual driving modes. No significant differences were found regarding either the duration or number of check glances across Super Cruise or manually executed lane changes. While drivers remained attentive during lane changes operating under a partial automated driving system, additional longer-term studies may be helpful to reinforce these findings that these safety behaviors persist after significant experience and usage.