Objective:The aim of this study was to review existing research into driver control transitions and to determine the time it takes drivers to resume control from a highly automated vehicle in noncr...

Takeover Time in Highly Automated Vehicles: Noncritical Transitions to and From Manual Control:

An important question in automated driving research is how quickly drivers take over control of the vehicle in response to a critical event or a take-over request. Although a large number of studies have been performed, results vary strongly. In this study, we investigated mean take-over times from 129 studies with SAE level 2 automation or higher. We used three complementary approaches: (1) a within-study analysis, in which differences in mean take-over time were assessed for pairs of experimental conditions, (2) a between-study analysis, in which correlations between experimental conditions and mean take-over times were assessed, and (3) a linear mixed-effects model combining between-study and within-study effects. The three methods showed that a shorter mean take-over time is associated with a higher urgency of the situation, not using a handheld device, not performing a visual non-driving task, having experienced another take-over scenario before in the experiment, and receiving an auditory or vibrotactile take-over request as compared to a visual-only or no take-over request. A consistent effect of age was not observed. We also found the mean and standard deviation of the take-over time were highly correlated, indicating that the mean is predictive of variability. Our findings point to directions for new research, in particular concerning the distinction between drivers’ ability and motivation to take over, and the roles of urgency and prior experience. © 2019 Elsevier Ltd

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Determinants of take-over time from automated driving : A meta-analysis of 129 studies

Automated driving can fundamentally change road transportation and improve quality of life. However, at present, the role of humans in automated vehicles (AVs) is not clearly established. Interviews were conducted in April and May 2015 with 12 expert researchers in the field of human factors (HFs) of automated driving to identify commonalities and distinctive perspectives regarding HF challenges in the development of AVs. The experts indicated that an AV up to SAE Level 4 should inform its driver about the AV's capabilities and operational status, and ensure safety while changing between automated and manual modes. HF research should particularly address interactions between AVs, human drivers and vulnerable road users. Additionally, driver-training programmes may have to be modified to ensure that humans are capable of using AVs. Finally, a reflection on the interviews is provided, showing discordance between the interviewees’ statements – which appear to be in line with a long history of HFs research – and the rapid development of automation technology. We expect our perspective to be instrumental for stakeholders involved in AV development and instructive to other parties.

/pdf/a-human-factors-perspective-on-automated-driving-3ucaknl108.pdf

A human factors perspective on automated driving

Take-over again: Investigating multimodal and directional TORs to get the driver back into the loop.

This is the peer reviewed version of the following article: Parker, S.K. and Grote, G. (2020), Automation, Algorithms, and Beyond: Why Work Design Matters More Than Ever in a Digital World. Applied Psychology, which has been published in final form at https://doi.org/10.1111/apps.12241. This article may be used for noncommercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.

Automation, Algorithms, and Beyond: Why Work Design Matters More Than Ever in a Digital World

In future automated driving systems, drivers will be free to perform other secondary tasks, not needing to stay vigilant in monitoring the car's activity. However, there will still be situations in which drivers are required to take-over control of the vehicle, most likely from a highly distracted state. While highly automated vehicles would ideally accommodate structured takeovers, providing ample time and warning, it is still very important to examine how drivers would behave when they are subjected to an unstructured emergency transition of control. In this study, we observed how participants (N=30) in a driving simulator performed after they experienced a loss of automation. We tested three transition time conditions, with an unstructured transition of control occurring 2 seconds, 5 seconds, or 8 seconds before the participants encountered a road hazard that required the drivers' intervention. Participants were given a passive distraction (watching a video) to do while the automated driving mode was enabled, so they needed to disengage from the task and regain control of the car when the transition occurred. Few drivers in the 2 second condition were able to safely negotiate the road hazard situation, while the majority of drivers in the 5 or 8 second conditions were able to navigate the hazard safely. Similarly, drivers in the 2 second condition rated the vehicle to be less trustworthy than drivers in the 5 and 8 second conditions. From the study results, we are able to narrow down a minimum amount of time in which drivers can take over the control of vehicle safely and comfortably from the automated system in the advent of an impending road hazard.

Emergency, Automation Off: Unstructured Transition Timing for Distracted Drivers of Automated Vehicles

As vehicle automation proliferates, the current emphasis on preventing driver distraction needs to transition to maintaining driver availability. During automated driving, vehicle operators are lik...

Distraction Becomes Engagement in Automated Driving

With automated driving systems, drivers may still be expected to resume full control of the vehicle. While structured transitions where drivers are given warning are desirable, it is critical to benchmark how drivers perform when transition of control is unstructured and occurs without advanced warning. In this study, we observed how participants (N=27) in a driving simulator performed after they were subjected to an emergency loss of automation. We tested three transition time conditions, with an unstructured transition of vehicle control occurring 2 seconds, 5 seconds, or 8 seconds before the participants encountered a road hazard that required the drivers' intervention. Few drivers in the 2 second condition were able to safely negotiate the road hazard situation, while the majority of drivers in 5 or 8 second conditions were able to navigate the hazard safely. Similarly, drivers in 2 second condition rated the vehicle to be less likeable than drivers in 5 and 8 second conditions. From the study results, we are able to narrow in on a minimum amount of time in which drivers can take over the control of vehicle safely and comfortably from the automated system in the advent of an impending road hazard.

Timing of unstructured transitions of control in automated driving

Automated driving systems that share control with human drivers by using haptic feedback through the steering wheel have been shown to have advantages over fully automated systems and manual driving. Here, we describe an experiment to elicit tacit expectations of behavior from such a system. A gaming steering wheel electronically coupled to the steering wheel in a full-car driving simulator allows two participants to share control of the vehicle. One participant was asked to use the gaming wheel to act as the automated driving agent while another participant acted as the car driver. The course provided different information and visuals to the driving agent and the driver to simulate possible automation failures and conflict situations between automation and the driver. The driving agent was also given prompts that specified a communicative goal at various points along the course. Both participants were interviewed before and after the drive, and vehicle data and drive video were collected. Our results suggest that drivers were able to interpret simple trajectory intentions, such as a lane change, conveyed by the driving agent. However, the driving agent was not able to effectively communicate more nuanced, higher level ideas such as availability, primarily due to the steering wheel being the control mechanism. Torque on the steering wheel without warning was seen most often as a failure of automation. Gentle and steady steering movements were viewed more favorably.

Exploring Shared Control in Automated Driving

Stating that one trusts a system is markedly different from demonstrating that trust. To investigate trust in automation, we introduce the trust fall: a two-stage behavioral test of trust. In the t...

Mishel Johns

Papers

Emergency, Automation Off: Unstructured Transition Timing for Distracted Drivers of Automated Vehicles

Distraction Becomes Engagement in Automated Driving

Timing of unstructured transitions of control in automated driving

Exploring Shared Control in Automated Driving

Behavioral Measurement of Trust in Automation: The Trust Fall