Differences in situational awareness between elderly and middle-aged drivers in level 2 automated vehicles versus nonautomated vehicles

Abstract This study explores how driving with Level 2 automation affects situational awareness. The experiment participants drove on an expressway in a Level 2 automated vehicle and then in a nonautomated vehicle for 30 ​min per vehicle. Fifteen middle-aged drivers and 15 elderly drivers participated. The experimental vehicle was a 2016 Nissan Serena equipped with the Society of Automated Engineers’ Level 2 automated driving system. In all runs, the most common cause of driver override was vehicles merging from on-ramps. Video recordings of the drivers’ gaze showed that elderly drivers’ situational awareness might be lower during automated driving than conventional driving. In a subjective survey, the middle-aged drivers reported difficulty in maintaining situational awareness during automated driving. To prevent accidents at on-ramps due to drivers’ reduced situational awareness, roads and the automated vehicle systems must be improved to mitigate losses in situational awareness.