•Few studies focused on a priori acceptability and intention to use fully automated driving.•Two thirds of the participants a priori accepted fully automated driving and wanted to use it.•Intention ...to use a fully automated car was predicted by attitudes and contextual acceptability.•Intention to use fully automated driving depends on the road type and the driving environment.•Intention to use fully automated driving depends on the interest in using it while impaired.
If previous research studied acceptability of partially or highly automated driving, few of them focused on fully automated driving (FAD), including the ability to master longitudinal control, lateral control and maneuvers. The present study analyzes a priori acceptability, attitudes, personality traits and intention to use a fully automated vehicle.
421 French drivers (153 males, M=40.2years, age range 19–73) answered an online questionnaire.
68.1% Of the sample a priori accepted FAD. Predictors of intention to use a fully automated car (R2=.671) were mainly attitudes, contextual acceptability and interest in impaired driving (i.e. the two components of FAD acceptability), followed by driving related sensation seeking, finally gender.
FAD preferred use cases were on highways, in traffic congestion and for automatic parking. Furthermore, some drivers reported interest in impaired driving misuses, despite awareness of their responsibility for both the vehicle and the driving. These results are discussed regarding previous knowledge about acceptability of advanced driving assistance systems and consequences for the use of fully automated cars.
Given the rise of automated vehicles from an engineering and technical perspective, there has been increased research interest concerning the Human and Computer Interactions (HCI) between vulnerable ...road users (VRUs, such as cyclists and pedestrians) and automated vehicles. As with all HCI challenges, clear communication and a common understanding-in this application of shared road usage-is critical in order to reduce conflicts and crashes between the VRUs and automated vehicles. In an effort to solve this communication challenge, various external human-machine interface (eHMI) solutions have been developed and tested across the world. This paper presents a timely critical review of the literature on the communication between automated vehicles and VRUs in shared spaces. Recent developments will be explored and studies analyzing their effectiveness will be presented, including the innovative use of Virtual Reality (VR) for user assessments. This paper provides insight into several gaps in the eHMI literature and directions for future research, including the need to further research eHMI effects on cyclists, investigate the negative effects of eHMIs, and address the technical challenges of eHMI implementation. Furthermore, it has been underlined that there is a lack of research into the use of eHMIs in shared spaces, where the communication and interaction needs differ from conventional roads.
•An automated driving training for non-professional drivers is proposed.•Training decreases response times and pedals interactions in cases of emergency.•Training helps optimizing trust in the ...automated driving system.•Performing an in-vehicle task increases response time in case of emergency.•The way control is recovered could impact the transition to manual control.
Automated driving (AD) introduces new skills needs for drivers to handle manual control recovery (MCR). In the scope of traffic safety, such skills should be investigated before this technology is available on public roads, especially in critical situations such as emergencies. The aim of the present study is to examine to what extend lack of training and in-vehicle task performance may impair MCR in a fully automated car. This study explores AD in a driving simulator, focusing on emergency MCR performance and trust in this system. 113 participants were involved. Training (simple vs. elaborated) and in-vehicle task performance (with vs. without) were manipulated. The MCR method (hands and feet used simultaneously or not) and its impact on response time and the number of pedals interactions were also examined. Training improved response time and decreased the number of interactions with the pedals. Moreover, the elaborated training group had fewer interactions with the pedals in the second and last system failure than in the first one. Performing an in-vehicle task slowed response time but did not significantly affect the number of interactions with the pedals. Response time was faster when hands and feet were used simultaneously in MCR. Elaborated training influenced trust in AD. Training drivers, using practice of the system and explaining its underlying logic, contributed to improve the human-automation performance. These results suggest the benefits of a training policy to enhance MCR performance and optimize trust in the system.
One major challenge for automated cars is to not only be safe, but also secure. Indeed, connected vehicles are vulnerable to cyberattacks, which may jeopardize individuals' trust in these vehicles ...and their safety. In a driving simulator experiment, 38 participants were exposed to two screen failures:
(i.e., no turn signals on the in-vehicle screen and instrument cluster) and
(i.e., ransomware attack), both while performing a non-driving related task (NDRT) in a conditionally automated vehicle. Results showed that objective trust decreased after experiencing the failures. Drivers took over control of the vehicle and stopped their NDRT more often after the explicit failure than after the silent failure. Lateral control of the vehicle was compromised when taking over control after both failures compared to automated driving performance. However, longitudinal control proved to be smoother in terms of speed homogeneity compared to automated driving performance. These findings suggest that connectivity failures negatively affect trust in automation and manual driving performance after taking over control. This research posits the question of the importance of connectivity in the realm of trust in automation. Finally, we argue that engagement in a NDRT while riding in automated mode is an indicator of trust in the system and could be used as a surrogate measure for trust.
Variable speed limits (VSL) aim at improving safety and traffic fluidity by increasing drivers’ awareness. In the present simulator study, VSL displayed on overhead gantries on a motorway were also ...displayed on a mobile phone, fixed on the vehicle’s centre console, with distance-based triggers (250 m vs. 500 m from the overhead gantry). Results showed drivers (N = 20) complied with the in-vehicle information, which was congruent with the upcoming gantry. The sooner the in-vehicle VSL, the faster the speed when speed limits increased. Similarly, the sooner the in-vehicle VSL, the slower the speed when speed limits decreased. Later in-vehicle VSL resulted in lower speed homogeneity, which is a safety concern. Speed homogeneity was greater when no in-vehicle VSL were displayed. Finally, the 70 mph VSL were affecting driving behaviour differently. These results suggested that there might be traffic disruption and more erratic longitudinal vehicle control on real roads.
There is a growing body of research on trust in driving automation systems. In this paper, we seek to clarify the way trust is conceptualized, calibrated and measured taking into account issues ...related to specific levels of driving automation. We find that: (1) experience plays a vital role in trust calibration; (2) experience should be measured not just in terms of distance traveled, but in terms of the range of situations encountered; (3) system malfunctions and recovery from such malfunctions is a fundamental part of this experience. We summarize our findings in a framework describing the dynamics of trust calibration. We observe that methods used to quantify trust often lack objectivity, reliability, and validity, and propose a set of recommendations for researchers seeking to select suitable trust measures for their studies. In conclusion, we argue that the safe deployment of current and future automated vehicles depends on drivers developing appropriate levels of trust. Given the potentially severe consequences of miscalibrated trust, it is essential that drivers incorporate the possibility of new and unexpected driving situations in their mental models of system capabilities. It is vitally important that we develop methods that contribute to this goal.
This study evaluated the effectiveness and acceptance of four connected vehicle features, i.e. Emergency Electronic Brake Lights (EEBL), Emergency Vehicle Warning (EVW), Roadworks warning (RWW) and ...Traffic Condition Warning (TCW) which were presented via a mobile phone mounted near the line of sight. A driving simulator study was conducted in which 36 drivers were exposed to different levels of urgent and critical situations. They involved the approach of an emergency vehicle, an emergency braking of a lead vehicle, a roadworks area and a congested section of a road. All these events took place in a simulated motorway scenario. In the EEBL event, the vehicle braking ahead with the brake lights on was either visible or not (between-subjects). Whereas no effect of RWW and TCW were observed on driving behaviour, results showed that drivers who were shown the EEBL warnings had shorter braking and decelerating response times, and a slower mean speed during the events, and this was independent of brake lights visibility. The EVW resulted in participants giving way to the emergency vehicle (i.e. staying on the slow lane instead of overtaking slower vehicles) more frequently than those who did not receive the warning. The mobile phone app was accepted and considered usable. Locating the mobile phone in different locations within the drivers' line of sight (i.e. dashboard, instrument cluster) did not impact significantly neither drivers’ attitudes nor behaviour. Additional in-vehicle information systems could enhance safety and allow emergency vehicles to get faster to their destination.
•Drivers were exposed to four connected in-vehicle features in a simulator study.•Emergency Electronic Brake Lights and Emergency Vehicle were urgent and critical.•A mobile app was used to convey the four different warnings about oncoming events.•Urgent and critical warnings had a positive impact on response times and manoeuvres.•The mobile app location did not impact drivers' attitudes nor behaviour.
Objective:
An experiment was performed in a driving simulator to investigate the impacts of practice, trust, and interaction on manual control recovery (MCR) when employing fully automated driving ...(FAD).
Background:
To increase the use of partially or highly automated driving efficiency and to improve safety, some studies have addressed trust in driving automation and training, but few studies have focused on FAD. FAD is an autonomous system that has full control of a vehicle without any need for intervention by the driver.
Method:
A total of 69 drivers with a valid license practiced with FAD. They were distributed evenly across two conditions: simple practice and elaborate practice.
Results:
When examining emergency MCR, a correlation was found between trust and reaction time in the simple practice group (i.e., higher trust meant a longer reaction time), but not in the elaborate practice group. This result indicated that to mitigate the negative impact of overtrust on reaction time, more appropriate practice may be needed.
Conclusions:
Drivers should be trained in how the automated device works so as to improve MCR performance in case of an emergency.
Application:
The practice format used in this study could be used for the first interaction with an FAD car when acquiring such a vehicle.
This paper discusses the design and evaluation of connected and cooperative vehicle in-vehicle sign designs displayed on a mobile phone: Emergency Electronic Brake Lights (EEBL), Emergency Vehicle ...Warning (EVW), Traffic Condition Warning, and Road Works Warning. Appropriateness and comprehension of each design alternative were assessed using quantitative (i.e. Likert scales) and qualitative (i.e. open-ended questions) methods. Forty-four participants took part in the study and were shown twelve dashboard camera videos presenting a total of eleven designs alternatives, displayed with or without a legend. Despite their appropriateness, EEBL and EVW signs displayed with a legend were better comprehended and less ambiguous than those displayed without a legend. Moreover, displaying a legend below the signs to warn drivers of an emergency braking ahead was efficient in low visibility condition and could potentially increase safety in critical situations.
•Designs based on existing ISO sign standards illustrating connected vehicle features were not always deemed the most appropriate by drivers.•Displaying a legend along with both the emergency braking and vehicle signs supported drivers' expected responses.•There is a discrepancy between new traffic signs design's appropriateness and comprehension.•Despite being rated as appropriate by participants, some signs were not properly understood.
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