Exploring the effectiveness of a digital voice assistant to maintain driver alertness in partially automated vehicles

Mahajan, Kirti; Large, David R.; Burnett, Gary; Velaga, Nagendra R.

Abstract

Objective: Vehicle automation shifts the driver's role from active operator to passive observer at the potential cost of degrading their alertness. This study investigated the role of an in-vehicle voice-based assistant (VA; conversing about traffic/road environment) to counter the disengaging and fatiguing effects of automation.
Method: Twenty-four participants undertook two drives– with and without VA in a partially automated vehicle. Participants were subsequently categorized into high and low participation groups (based on their proportion of vocal exchanges with VA). The effectiveness of VA was assessed based on driver alertness measured using Karolinska Sleepiness Scale (KSS), eye-based sleepiness indicators and glance behavior, NASA-TLX workload rating and time to gain motor readiness in response to take-over request and performance rating made by the drivers.
Results: Paired samples t-tests comparison of alertness measures across the two drives were conducted. Lower KSS rating, larger pupil diameter, higher glances (rear-mirror, roadside vehicles and signals in the drive with VA) and higher feedback ratings of VA indicated the efficiency of VA in improving driver alertness during automation. However, there was no significant difference in alertness or glance behavior between the driver groups (high and low-PR), although the time to resume steering control was significantly lower in the higher engagement group.
Conclusion: The study successfully demonstrated the advantages of using a voice assistant (VA) to counter these effects of passive fatigue, for example, by reducing the time to gain motor-readiness following a TOR. The findings show that despite the low engagement in spoken conversation, active listening also positively influenced driver alertness and awareness during the drive in an automated vehicle.

Citation

Mahajan, K., Large, D. R., Burnett, G., & Velaga, N. R. (2021). Exploring the effectiveness of a digital voice assistant to maintain driver alertness in partially automated vehicles. Traffic Injury Prevention, 22(5), 378-383. https://doi.org/10.1080/15389588.2021.1904138

• Journal Article Type: Article
• Acceptance Date: Mar 11, 2021
• Online Publication Date: Apr 21, 2021
• Publication Date: Apr 21, 2021
• Deposit Date: Apr 1, 2021
• Publicly Available Date: Apr 22, 2022
• Journal: Traffic Injury Prevention
• Print ISSN: 1538-9588
• Electronic ISSN: 1538-957X
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Issue: 5
• Pages: 378-383
• DOI: https://doi.org/10.1080/15389588.2021.1904138
• Keywords: Public Health, Environmental and Occupational Health; Safety Research
• Public URL: https://nottingham-repository.worktribe.com/output/5427487
• Publisher URL: https://www.tandfonline.com/doi/abs/10.1080/15389588.2021.1904138
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Traffic Injury Prevention on 21/04/2021, available online: https://www.tandfonline.com/doi/abs/10.1080/15389588.2021.1904138