Search

International audience; During automated driving (SAE Level 3), drivers can delegate control of the vehicle and monitoring of the road to an automated system. They may then devote themselves to tasks other than driving and gradually lose situational awareness (SA). This could res ult in difficulty in regaining control of the vehicle when the automated system requires it. In this simulator study, the level of SA was manipulated through the time spent performing a nondriving task (NDRT), which alternated with phases where the driver could monitor the driving scene, prior to a critical takeover request (TOR). The SA at the time of TOR, the visual behaviour after TOR, and the takeover quality were analysed. The results showed that monitoring the road just before the TOR allowed the development of limited perception of the driving situation, which only partially compensated for the lack of a consolidated mental model of the situation. The quality of the recovery, assessed through the number of collisions, was consistent with the level of development of SA. The analysis of visual behaviour showed that engagement in the non-driving task at the time of TOR induced a form of perseverance in consulting the interface where the task was displayed, to the detriment of checking the mirrors. These results underline the importance of helping the driver to restore good SA well in advance of a TOR.

Which are the subjective feelings and objective risks of driving in an automatic mode when holding the steering wheel or not holding it? Two conditions of simulated driving of a partially automated car have been tested (hands-on and hands-off), in two situations of driving on highways including critical events forcing the driver to take over. The user subjective experiences were compared: the situation awareness, feelings of safety, control, attention, on-board activities, psychological and physical comfort were analyzed on the basis of in-depth interviews right after the activity. For the critical situations designed, the performance results indicate a negative impact of the hands-off condition on the takeover. The hands-off condition is appreciated for its comfort and the multi-activity it allows, but the hands-on condition is objectively and subjectively safer in critical situations.

21st Congress of the International Ergonomics Association (IEA 2021), VANCOUVER, CANADA, 14-/06/2021 - 18/06/2021; International audience; Using an integrative user-centered approach, the research project aimed at designing and assessing an adaptive HMI to improve the safety and the quality of the take-over in a level-3 automated vehicle. Future autonomous driving users confirmed the need for the monitoring systems to improve safety as long as they are simple and not intrusive. They request specific information to understand and initiate appropriated actions in case of a critical situation. However, to avoid overloading and detri-mental effects, it is important that the system limits the amount of infor-mation at the right moment.

SCOOP@F was a French project for deployment and validation of a Cooperative Intelligent Transport System (C- ITS). The primary aim was to provide communication between drivers and road operator to improve road safety. The effectiveness of this communication relied on drivers’ acceptation to be compliant with received indication. Because of the lack of messages received by drivers, Field Operational Test studies did not appropriately assess acceptability. A focus group was thus carried out to further complete results. Eight participants were recruited after using SCOOP@F for a week. They were asked to discuss four topics: interaction with the system, information for road safety, for trip optimization, and extended functions. Results suggested that there were ideal functions, commonly expected, and additional functions, more related to the variety of drivers’ needs and expectations. In conclusion, we propose that C-ITS should combine several functionalities to benefit road safety., Le projet SCOOP@F visait à déployer un Système Coopératif de Transport Intelligent pour améliorer de la sécurité routière. L’efficacité de ce dispositif repose sur la propension des conducteurs à suivre les indications qu’ils reçoivent. Pour cela, le système doit être accepté. Plusieurs études d’évaluation de l’acceptabilité menées sur le terrain ont été limitées par le manque d’exposition aux messages. Un focus group a donc été élaboré pour compléter les résultats. Huit participants ont été recrutés après avoir utilisé le système pendant une semaine. Ils se sont exprimés sur les interactions avec le dispositif, les informations liées à la sécurité, l’optimisation du trajet et les extensions de fonction. Les résultats indiquent que des fonctions idéales sont communément attendues, tandis que des fonctions supplémentaires sont plus hétérogènes. Le principal enseignement est que pour être accepté, le système ne doit pas se limiter à communiquer seulement des informations concernant la sécurité.

It is well known that collision avoidance is a driving skill that increases with drivers’ experience, which set up efficient search strategy. However, an automated search strategy that works in most situations may be unsuitable in others. As demonstrated by the “look-but-failed-to-see” accident type, we hypothesise that such unsuitability emerges from a particular combination of driver–task–environment interactions. We test different combinations according to contextual experience of the road-site, the necessity to anticipate danger, and the possibility of doing so. Results show an important difference between the use of environment-related expectations and practice-related ones. Even though contextual experience increased anticipation whatever the situation, knowledge of danger presented some surprising results: it led to appropriate processing of the situation when anticipation was not necessary or was not possible, but it also created a lack of expectation when anticipation was necessary and was possible. We suggest that practice-related expectations “overcome” environment-related ones when hazard need to be anticipated. The outcome of this phenomenon are discussed.

Circumstances where "looked-but-failed-to-see" accidents arise are a particular subject of study. In order to better understand why normal drivers could miss a relevant event signaling danger, more than 500 accidents were analyzed in-depth with regard to driver-environment-goal interactions. Results show four typical situations that imply two distinct mechanisms. When a failure arose at the perceptual stage, drivers actually never saw the danger while they were going straight at a junction or turning left to park their car. When failure arose at the processing stage, there was evidence that drivers saw the danger even when their recall of it was lacking. In fact, drivers saw the danger too late to avoid collision when they were overtaking another road user or trying to find his/her way. These are called "looked-but-failed-to-see-accidents". Accident patterns are discussed according to driver's goal involvement and local setting to suggest directions for further investigation with a special emphasis on change blindness.

Objective: The study addressed the role of familiarization on a driving simulator with a forward collision warning (FCW) and investigated its impact on driver behavior. Background: Drivers need a good understanding of how an FCW system functions to trust it and use it properly. Theoretical and empirical data suggest that exploring the capacities and limitations of the FCW during the learning period improves operating knowledge and leads to increased driver trust in the system and better driver-system interactions. The authors tested this hypothesis by comparing groups of drivers differing in FCW familiarity. Method: During the familiarization phase, familiarized drivers were trained on the simulator using the FCW, unfamiliarized drivers simply read an FCW manual, and control drivers had no contact with the FCW. During the test, drivers drove the simulator and had to interact with traffic; both familiarized and unfamiliarized drivers used the FCW, whereas controls did not. Results: Simulator familiarization improved driver understanding of FCW operation. Driver-system interactions were more effective: Familiarized drivers had no collisions, longer time headways, and better reactions in most situations. Familiarization increased trust in the FCW but did not raise system acceptance. Conclusion: Familiarization on the simulator had a positive effect on driver-system interactions and on trust in the system. The limitations of the familiarization method are discussed in relation to the driving simulator methodology. Application: Practicing on a driving simulator with driving-assistance systems could facilitate their use during real driving.

Drivers have to focus their attention on a danger to become aware of it. Change blindness paradigms are therefore relevant to studying the ability to detect danger. However, research has not yet focused on the role of two essential factors in guiding drivers’ attention: driving experience and the specific needs for performing a manoeuvre. Based on a previous analysis of real accident situations, we used a one-shot paradigm with static scenes to test observers’ ability to detect various changes as a function of their driving experience, the manoeuvre envisaged and the environmental context. The results showed that change detection depends greatly on driving experience when planning to cross a junction or to turn left, while it depends more on the environmental setting and task complexity when seeking a direction. The results were not conclusive, however, in explaining how drivers failed to notice that the vehicle ahead of them was turning when they considered an overtaking manoeuvre. We discuss the contributions of our research in relation to the possibilities of using change blindness as a measurement tool in studies on automobile driving.