Driven to discussion: engaging drivers in conversation with a digital assistant as a countermeasure to passive task‐related fatigue

Abstract

Using a Wizard-of-Oz approach, we explored the effectiveness of engaging drivers in conversation with a digital assistant as an operational strategy to combat the symptoms of passive task-related fatigue. Twenty participants undertook two 30-minute drives in a medium-fidelity driving simulator between 13:00 and 16:30, when circadian and homeostatic influences naturally reduce alertness. Participants were asked to follow a lead-car travelling at a constant speed of 68mph, in a sparsely-populated UK motorway scenario. During one of the counterbalanced drives, participants were engaged in conversation by a digital assistant ('Vid'). Results show that interacting with Vid had a positive effect on driving performance and arousal, evidenced by better lane-keeping, earlier response to a potential hazard situation, larger pupil diameter, and an increased spread of attention to the road-scene (i.e. fewer fixations concentrated on the road-centre indicating a lower incidence of 'cognitive tunnelling'). Drivers also reported higher levels of alertness and lower sleepiness following the Vid drive. Subjective workload ratings suggest that drivers exerted less effort to 'stay awake' when engaged with Vid. The findings support the development and application of in-vehicle natural language interfaces, and can be used to inform the design of novel countermeasures for driver fatigue.

Long automated driving phase affects take‐over performance

“…The present results suggest that even with non‐driving‐related tasks, especially when these are prone to induce mental underload or drowsiness, there could be a serious risk in more complex take‐over situations. Preventive solutions could include using more diverse non‐driving tasks to break the monotony [15, 34, 46, 47, 49, 50] or providing a road awareness recall when the out‐of‐the‐loop state (or drowsiness) is detected or predicted by the system [51]. These solutions could feature as recommendations for use of the function, enabling drivers to enjoy the benefits of long periods under autonomous mode while maintaining a good awareness of the road situation.…”

Exploring the benefits of conversing with a digital voice assistant during automated driving: A parametric duration model of takeover time

“…Various studies have claimed the alerting effects of engaging in an active conversation for the drivers while driving (27,28). These benefits of conversation can be extended to mitigate the effects of passive fatigue during automated driving, and specifically the impact on the process of gaining motor readiness (29), (30).…”

Lessons from Oz

“…It enables the driver to build expectations, supporting the development of an appropriate mental model. Instigating conversation can also help combat issues of passive task-related fatigue [8,9].…”

“…This work has revealed that an on-board agent with whom the driver can interact freely using conversational language can minimise cognitive demand and workload [7]. In addition, it can be an effective counter-measure to passive task-related fatigue [8,9], increase levels of trust and acceptance in autonomous vehicles [10,11] and enrich environmental engagement [12]. A particular challenge in conducting this work has been to create and deliver an 'authentic' CUI experience, not least to ensure that we do not violate users' high expectations of future technology or indeed how they expect, or would choose to interact.…”