Driver behaviour and driver experience of partial and fully automated truck platooning – a simulator study

Abstract

Introduction This paper builds our knowledge of truck driver behaviour in and experience of automated truck platooning, focusing on the effect of partially and fully automated truck platoons on driver workload, trust, acceptance, performance, and sleepiness. Methods Twenty-four male drivers experienced three conditions in a truck driving simulator, i.e., baseline, partial automation, and full automation: the baseline condition was driving with standard cruise control; partial automation was automated longitudinal control ten metres behind the truck in front, with the driver having to steer; and full automation was automated longitudinal and lateral control. Each condition was simulated in three situations: light traffic, heavy traffic, and heavy traffic plus fog. Results The experiment demonstrated that automation affects workload. For all workload measures, partial automation produced higher workload than did the full-automation or baseline condition. The two measures capturing trust, i.e., the Human Trust in Automated Systems Scale (HTASS) and Cooper-Harper Scales of Workload, Temporal Load, Situation Awareness, and Trust, were consistent and indicated that trust was highest under the baseline condition, with little difference between partial and full automation. Driver acceptance of both levels of automation was lower than acceptance of baseline. Drivers rated their situation awareness higher for both partial and full automation than for baseline, although both levels of automation led to higher sleepiness. Conclusions Workload was higher for partial than for full automation or the baseline condition. Trust and acceptance were generally highest in the baseline condition, and did not differ between partial and full automation. Drivers may believe that they have more situation awareness during automated driving than they actually do. Both levels of automation led to a higher degree of sleepiness than in the baseline condition. The challenge when implementing truck platooning is to develop a system, including human-machine interaction (HMI), that does not overburden the driver, properly addresses driver sleepiness, and satisfies current legislation. The system also must be trusted and accepted by drivers. To achieve this, the development of well-designed HMI will be crucial.

A human centric framework for the analysis of automated driving systems based on meaningful human control

“…Part of this reason is that the driver must be able to retake operational control if this is required, for example, due to platoon break-up or complicated road sections. Previous studies have shown that control transition requires a necessary amount of time that varies per driver and per moment (Merat et al 2014), and the level of awareness for the driver is also variable at the moment of control transition (Hjälmdahl, Krupenia, and Thorslund 2017). This poses questions in regard to safety at the point of the transition of control (Axelsson 2017), and also the design of the ADS to allow a driver this time while still maintaining an acceptable level of control.…”

How does long trip affect on driving performance, eye blinks and awareness of sleepiness among commercial drivers? A naturalistic driving test study

“…If a participant is in high spirits, for example, he/she may feel less sleepy, even after a long distance driving task. Consequently, future studies should systematically focus on how to capture precise data using accurate test techniques, such as through the driving simulator [27]. Third, self-reporting of individual sleepiness level through validated questionnaires may not be accurate due to drivers' faulty memory or incorrect judgment at the time of reporting, at which point they could have a short attention lapse and experience microsleep.…”

Full platoon control in Truck Platooning: A Meaningful Human Control perspective

“…The first is a loss of situation awareness and vigilance, which results from limited vision of the road for drivers in following trucks [10]. The second relates to the platoon lead driver, who now carries responsibility over the entire platoon, and possibly also operational control, which will inadvertently require a high level of trust (in the system and/or themselves) [11]. From a following driver's perspective, it is important to understand the chain of control within a truck platoon.…”