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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.

Taking a motor planning perspective, this study investigates whether haptic force cues displayed on the steering wheel are more effective than visual cues in signaling the direction of an upcoming lane change. Licensed drivers drove in a fixed-base driving simulator equipped with an active steering system for realistic force-feedback. They were instructed to make lane changes upon registering a directional cue. Cues were delivered according to the movement precuing technique employing a pair of precues and imperative cues which could be either visual, haptic, or crossmodal (a visual precue with a haptic imperative cue, and vice versa). The main dependent variable was response times. Additional analyses were conducted on steering wheel angle profiles and error rates. Conditions with a haptic imperative cue produced considerably faster responses than conditions with a visual imperative cue, irrespective of the precue modality. Valid and invalid precues produced the typical gains and costs, with one exception. There appeared to be little cost in response time or steering errors associated with invalid cueing when both cues were haptic. The results are consistent with the hypothesis that imperative haptic cues facilitate action selection while visual stimuli require additional time-consuming cognitive processing.

International audience; The installation of shoulders on rural roads to create more forgiving roads encourages drivers to cut corners on right-hand bends, but the underlying mechanisms are poorly understood. Since eye movements and steering control are closely coupled, this study investigated how the presence of a shoulder influences drivers' gaze strategies. To this end, eighteen drivers negotiated right-hand bends with and without a shoulder on a simulated rural road. In the presence of a shoulder, participants modified their visual sampling of the road by directing their gaze further inside the bend. At the same time, their lane position was deviated inward throughout the bend and the vehicle spent more time out of the lane. These results suggest that the shoulder influences the visual processes involved in trajectory planning. Recommendations are made to encourage drivers to keep their eyes and vehicle in the driving lane when a shoulder is present.

This work concerned the assessment of drivers’ attentional state in highly automated vehicle. A specific attention had been placed on the analysis of driver’s visual strategies. The first two experiments dealt on the link between distraction, visual strategies and takeover quality. To that end, divers had to realize non-driving activities during automated driving and had to deal with a non-planned takeover in obstacle avoidance situation. Results showed that there was an effect of the gaze location at the time of the takeover request but also an effect of the development of situational awareness on the takeover quality. The last experiment looked at the effect of different automation modes on driver inattention in the form of mindwandering. The evolution of mindwandering over time has been estimated by modeling the driver’s visual strategies. Results showed that mindwandering increased strongly to reach high levels very quickly and then fluctuated around a stable trend. These results are discussed in the context of the development of driver monitoring systems for autonomous vehicle.; Ce travail a porté sur l'évaluation de l'état attentionnel de conducteurs à bord d'un véhicule hautement automatisé. Un accent particulier a été mis sur l'analyse des stratégies visuelles du conducteur. Les deux premières expérimentations ont porté sur le lien entre distraction, stratégies visuelles et qualité de la reprise en main. Pour ce faire, les conducteurs ont réalisé des activités non liées à la conduite pendant une phase de conduite autonome et ont dû faire face à une demande de reprise en main non planifiée dans une situation d'évitement d'obstacle. Les résultats montrent qu'il existe un effet de la localisation du regard au moment de la demande de reprise en main mais également du niveau de l’élaboration de la conscience de la situation sur la qualité de la reprise en main. La dernière expérimentation s'est intéressée à l'effet de différentes modalités d'automatisation sur l'inattention du conducteur, prenant la forme d'un vagabondage de la pensée. L'évolution du vagabondage au fil du temps a été estimé en modélisant les stratégies visuelles des conducteurs. Les résultats montrent que le vagabondage augmente très fortement pour atteindre des niveaux élevés très rapidement puis fluctue autour d'une tendance stable. Ces résultats sont discutés dans la perspective du développement des outils d'évaluation de l'état du conducteur à bord des véhicules autonomes.

Risk perception is a crucial aspect that needs to be investigated in order to promote the acceptance of autonomous vehicles in shared spaces with pedestrians. This thesis is structured around three empirical contributions. The first contribution focuses on the possibility of modelling the dynamics of subjective risk perception using an impulse response. The performance obtained is rather uneven and reflects a large inter-individual variability in the risk assessment strategy. The other two contributions demonstrate that risk perception can be measured in real time and in complex dynamic interactions using both subjective and electrodermal response measures. The results of these contributions are based on Bayesian network modelling that allows for the simultaneous analysis of relationships between dynamic factors and risk perception measures. The conclusions of this work provide theoretical elements on the links between the implicit and explicit dimensions of risk perception, as well as concrete elements to take into account human factors in the development of navigation behaviors of autonomous vehicles.; La perception du risque est un aspect crucial qu'il est nécessaire d'étudier dans le but de favoriser l'acceptation des véhicules autonomes dans des espaces partagés avec des piétons. Ce travail s'articule autour de trois contributions empiriques. La première contribution porte sur la possibilité de modéliser la dynamique de perception subjective du risque par le biais d'une réponse impulsionnelle Les performances obtenues sont assez inégales et reflètent une grande variabilité interindividuelle dans la stratégie d'évaluation du risque. Les deux autres contributions mettent en évidence que la perception du risque peut se mesurer en temps réel et dans des interactions dynamiques complexes en s'appuyant à la fois sur des mesures subjectives et des mesures de réactions électrodermales.Les résultats de ces contributions sont basés sur une modélisation par réseau bayésien permettant d'analyser simultanément les relations entre facteurs dynamiques et mesures de perception du risque. Les conclusions de ces travaux apportent des éléments théoriques sur les liens entre les dimensions implicite et explicite du risque ressenti, ainsi que des éléments concrets permettant de prendre en compte le facteur humain dans le développement des comportements de navigation des véhicules autonomes.