Transitioning to manual driving requires additional time after automation deactivation. (May 2018)

• Record Type: Journal Article
• Authors: Vogelpohl, Tobias; Kühn, Matthias; Hummel, Thomas; Gehlert, Tina; Vollrath, Mark
• Is Part Of: Transportation research. Volume 55(2018)
• Page Start: 464
• Page End: 482
• Publication Date: 2018-05
• Subjects: Automated driving -- Situation awareness -- Take-over request -- Transition to manual -- Distraction -- Driver assistance; Automobile drivers -- Psychology -- Periodicals; Automobile driving -- Psychological aspects -- Periodicals; Transportation -- Psychological aspects -- Periodicals; 629.283019
• DOI: 10.1016/j.trf.2018.03.019
• Languages: English
• ISSNs: 1369-8478

Abstract

Highlights: We analyzed transitions of control from highly automated driving to manual driving. We studied drivers' reactions to sudden events after a take-over. Drivers' automation deactivation may not necessarily imply situation awareness. Highly distracted automated drivers need more time to rebuild situation awareness. Future systems should provide support before and after the automation deactivation. Abstract: Previous research has shown that drivers are generally able to deactivate the automation in an automated vehicle after a Take-Over Request (TOR) in a relatively short time frame of approximately 3–5 s on average (e.g. Gold, Körber, Hohenberger, Lechner, & Bengler, 2015; Melcher, Rauh, Diederichs, Widlroither, & Bauer, 2015). However, it is yet unclear if drivers are able to adequately react to unexpected traffic events shortly after the transition of control and some studies have shown that stabilizing the vehicle after this transition may take longer than deactivating the automation (e.g. Merat, Jamson, Lai, Daly, & Carsten, 2014). This study addresses this issue by examining the drivers' reactions following a TOR during an automated drive with highly distracting Non-Driving Related Tasks (NDRTs). We investigated the reactions of N = 60 participants to five complex take-over scenarios with unexpected events after the TOR in a driving simulator study. Participants were assigned to two distracted conditions with automation (playing a game on a tablet pc, reading on a tablet pc), a no task condition and a manual driving condition. 90% of the participants in the distracted conditions deactivated the automation after 7–8 s. Brake reaction times to the unexpected event were comparable between automation and manual driving conditions. However, compared to manual drivers, distracted drivers with automation showed a delay of up to 5 s regarding the time to the first gaze to the side mirror and the first gaze to the speedometer after the TOR. Distracted drivers are relatively fast at taking back control over the vehicle after an automated drive and are generally able to react to the onset of sudden events. However, they may require additional time and assistance to fully perceive and understand complex traffic situations and to reach a level of situation awareness comparable to manual drivers. Future research should therefore aim to support the driver during the transition to manual driving, in order to avoid critical situations and to systematically build up situation awareness.