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Objective To implement auditory continual feedback into the interface design of a Level 3 automated vehicle and to test whether gaze behavior and reaction times of drivers improved in take-over situations. Background When required to assume manual control in take-over situations, drivers of Level 3 automated vehicles are less likely than conventional drivers to spot potential hazards, and their reaction time is longer. Therefore, it is crucial that the interface of Level 3 automated vehicles will be designed to improve drivers’ performance in take-over situations. Method In two experiments, participants drove a simulated route in a Level 3 automated vehicle for 35 min with one imminent take-over event. Participants’ gaze behavior and performance in an imminent take-over event were monitored under one of three auditory interface designs: (1) Continual feedback. A system that provides verbal driving-related feedback; (2) Persistent feedback. A system that provides verbal driving-related feedback and a persistent beep; and (3) Chatter feedback. A system that provides verbal non-driving-related feedback. Also, there was a control group without feedback. Results Under all three auditory feedback designs, the number of drivers' on-road glances increased compared to no feedback, but none of the designs shortened reaction time to the imminent event. Conclusion Increasing the number of on-road glances during automated driving does not necessarily improve drivers’ attention to the road and their reaction times during take-overs. Application Possible implications for the effectiveness of auditory continual feedback should be considered when designing interfaces for Level 3 automated vehicles.

One of the most significant safety concerns regarding Highly-Automated Driving (HAD) is drivers’ ability to regain control of the vehicle safely. Vibro-tactile alerts were already suggested as an effective modality for Take-Over Requests (TOR) in terms of reducing reaction times. However, it is not clear yet whether such alerts should be compatible or incompatible with the location of hazards that might be present when the TOR is initiated. Studies regarding tactile directionality in other domains, and in manual vehicles have found mixed results. It is argued that part of the contradictory evidence may be related to contextual differences between the driving domain and other domains. Thus, this study aimed to test which directional design would be preferable for TORs in time-critical situations. Twenty-seven participants drove a highly-automated vehicle on a highway with two lanes in each travel direction, in a driving simulator. Each participant experienced five TORs in which they were required to take control and divert their vehicle away from an impending hazard that shut down an entire lane and was situated four seconds ahead. The disengagement of the autonomous driver was signaled using a tactile alert. For the first group, the tactile alert was directed towards the hazard (incompatible with the required action), for the second, it was directed away from it (compatible with the required action), and for the control group, the alert was non-directional. Results showed that drivers using the compatible alert reacted faster and more accurately than those using the incompatible alert. Participants using the non-directional alert reacted slower and less accurately than participants in both directional groups. The results contradict previous findings in the manual driving domain, where drivers are faster and more accurate to respond when the alert is compatible with the location of the hazard and not with the direction of the required action. It is argued that these discrepancies stem from the modified HAD driving task demands where drivers are disengaged from the driving task for long periods and are less aware of the driving environment. The implications for the design of autonomous vehicles are discussed.

During prolonged periods of autonomous driving, drivers tend to shift their attention away from the driving task. As a result, they require more time to regain awareness of the driving situation and to react to it. This study examined the use of informative automation that during Level-3 autonomous driving provided drivers with continuous feedback regarding the vehicle’s actions and surroundings. It was hypothesized that the operation of informative automation will trigger drivers to allocate more attention to the driving task and will improve their reaction times when resuming control of the vehicle. Sixteen participants drove manual and autonomous driving segments in a driving simulator equipped with Level-3 automation. For half of the participants, the informative automation issued alerts and messages while for the other half no messages were issued (control). The number of on-road glances served as a proxy for drivers’ attention. Drivers’ performance on handling an unexpected automation failure event was measured using their time-to-brake and time-to-steer. Results showed that drivers using the informative automation made more frequent on-road glances than drivers in the control group. Yet, there were no significant differences in reaction times to the automation failure event between the groups. Explanations and implications of these results are discussed.

“Iron-Dome” is an anti-rocket air defense system placed around major urban areas of Israel. It was created to provide citizens with greater deal of protection against hostile rocket attacks. A study was conducted to examine whether civilians' experience with the “Iron-Dome” system affects people's perceived reliability of it, their trust in it, and their complacency to hostile rocket alerts. During the 2014 Israel-Gaza conflict (operation “Protective Edge”), an online questionnaire was used to measure civilian respondents' perceptions and actions. Results indicated that people living in geographical areas who had more experience with rocket attacks and thereby with the “Iron-Dome” system, perceived it as less reliable, had lower trust in it, and were less complacent. These results show that people's interaction with the “Iron-Dome” corresponds to the common prediction of theoretical models of human-automation interaction. This understanding may assist in planning of implementation programs and guidance of civilians for other mass protection systems in the future.