Influence of Headlight Design on Sensory Conspicuity of Powered Two-Wheelers

Conspicuity of Powered Two Wheelers (PTW) according to their frontal headlight design was evaluated in a car Daytime Running Light (DRL) environment. Three innovative headlight arrangements were studied: a triangle configuration, a lighted helmet and a colored frontal headlight. It was found that the helmet and the colored configuration led to better PTW detection performances than the standard configuration (a unique white headlight), especially when the PTW was far away. The triangle configuration did not prove to be effective. The theoretical and practical implications of these results are discussed

A Simulator-Based Street-Crossing Training for Older Pedestrians: Short and Long Term Effects

The study aimed at developing and assessing a training method to improve the safety of elderly pedestrians with a simulator-based street-crossing technique specially designed to their needs and difficulties. Twenty seniors were enrolled in a street-crossing training program, and twenty other seniors were assigned to the control group (internet-use training). Before the training, immediately after it, and 6 months later, street-crossing decisions and behaviors were assessed using a simulated street-crossing task. The results showed that the simulator-based training enhanced the safety of the elderly pedestrians. However, the way in which they took into account the speed of the approaching car in their decisions and behaviors had not improved. The lack of effectiveness of training in the use of speed may reveal age-related sensory and cognitive impairments that our simulator-based method could not alleviate. The results of this study stressed the importance of greater attention to senior street-crossing retraining

Evaluation of Motorcycle Conspicuity in a Car DRL Environment

Daytime Running Lights (DRL) on motorcycles have been shown to counteract the inherently lower sensory conspicuity of these vehicles and to significantly improve their safety. The advantage of the use of DRL exclusively by motorcycles is presently becoming lost by the increasing use of DRLs on cars. The present experiment aimed at evaluating the effects of car DRLs on motorcycle perception in a situation that specifically brought attentional conspicuity to bear. Photographs representing complex urban traffic scenes were displayed to 24 participants who were asked to detect vulnerable road users (motorcyclists, bicyclists, pedestrians) appearing at different locations and distances. Car DRLs noticeably hampered motorcycle perception compared to conditions where car lights were not on, especially when the motorcycle was at a greater distance from the observer and when it was located in the central part of the visual scene. Car DRLs were also detrimental to the perception of bicyclists and pedestrians. These findings suggest that more attention should be paid to motorcyclists and other vulnerable road users when introducing car DRLs. Several means of improving motorcycle conspicuity in car DRL environments are discussed

A Cybernetic Perspective on Car Following in Fog

Drivers often drive at a closer time headway (THW) in fog than in clear whether conditions for similar speed ranges (White & Jeffery, 1980). Closer following is generally considered more dangerous. The hypothesis pursued in this paper is that drivers experience a perceptual-motor benefit from driving closer in fog that results in greater (or equivalent) safety and reduced driving demand. A computational car following model with an experimentally constructed perceptual module is introduced and used to demonstrate that under some conditions, closer following in fog is indeed beneficial because it effectively reduces drivers’ perceptual delay by a sufficient amount to improve controllability of the gap so much that the variability in THW reduces more than (or as much as) the adopted decrease in target THW

Familiarization with a Forward Collision Warning on driving simulator: cost and benefit on driversystem interactions and trust

International audienceIntroducing Advanced Driver Assistance Systems (ADAS) into the vehicle could improve drivers’ comfort and reduce road crashes. However, suitable methods are required to study driver/system interactions. In fact, ADAS generate critical use cases, i.e. situations where alarms, or absence of alarms, can be negative for safety. The present study aimed at evaluating the impact of getting familiar, by means of a driving simulator, with critical situations when using the Forward Collision Warning system (FCW). We hypothesized that experiencing the system’s function in critical situations would improve drivers’ performance and their trust in the FCW. We compared judgments and driving performance of three independent groups: a “control group” where drivers did not use the FCW, an “unfamiliarized group” where drivers used the FCW without having been familiarized with the system, and a “familiarized group” where drivers used the FCW after having been familiarized. Results showed that familiarization made driver/system interactions more effective and safer. Moreover, familiarized drivers rated the system more positively than unfamiliarized drivers. However, familiarization decreased drivers’ self-confidence and did not prevent from haste when overtaking slow vehicles. We discussed the relevance of using a driving simulator in FCW’s studies and the possibility to transfer skills and knowledge to field operational tests. Finally, we proposed possible improvements to make the familiarization with the system still more effective.Introduire des systèmes avancés d’aide au conducteur dans le véhicule pourrait augmenter le confort des conducteurs et réduire le nombre d’accidents. Toutefois, des méthodes d’évaluations adaptées sont nécessaires à l’étude des interactions conducteur/système. Les systèmes d’aide génèrent effectivement des cas d’usage critiques, i.e. des situations ou les alertes, ou l’absence d’alertes, peuvent être négatives pour la sécurité. L’objectif de la recherche était d’évaluer l’impact de la familiarisation avec les cas critiques d’usage du Forward Collision Warning (FCW) sur simulateur de conduite. Nous avons testé l’hypothèse selon laquelle l’expérience du fonctionnement du FCW dans des situations critiques d’usage augmente la performance de conduite et la confiance des conducteurs dans le système. Nous avons comparé les jugements et la performance de conduite de trois groupes expérimentaux : un groupe contrôle où les conducteurs n’utilisaient pas le FCW, un groupe « non familiarisé » où les conducteurs utilisaient le système sans avoir été familiarisés et un groupe « familiarisé » où les conducteurs utilisaient le système après avoir été familiarisés. Les résultats montrent que la familiarisation rend les interactions conducteur/système plus efficaces et plus sûres. Par ailleurs, les conducteurs familiarisés ont des opinions plus positives sur le FCW comparé aux non familiarisés. Néanmoins, la familiarisation diminue la confiance des participants dans leur capacité de conduite. De plus, elle ne permet pas d’éviter que les conducteurs dépassent de façon trop précipitée les véhicules lents. Nous discutons la pertinence du simulateur pour l’étude du FCW et la possibilité de transfert des connaissances à la conduite sur route réelle. Finalement, nous proposons des améliorations pour rendre la familiarisation avec le système plus efficace

Familiarization with a Forward Collision Warning on driving simulator: cost and benefit on driversystem interactions and trust

Introducing Advanced Driver Assistance Systems (ADAS) into the vehicle could improve drivers’ comfort and reduce road crashes. However, suitable methods are required to study driver/system interactions. In fact, ADAS generate critical use cases, i.e. situations where alarms, or absence of alarms, can be negative for safety. The present study aimed at evaluating the impact of getting familiar, by means of a driving simulator, with critical situations when using the Forward Collision Warning system (FCW). We hypothesized that experiencing the system’s function in critical situations would improve drivers’ performance and their trust in the FCW. We compared judgments and driving performance of three independent groups: a “control group” where drivers did not use the FCW, an “unfamiliarized group” where drivers used the FCW without having been familiarized with the system, and a “familiarized group” where drivers used the FCW after having been familiarized. Results showed that familiarization made driver/system interactions more effective and safer. Moreover, familiarized drivers rated the system more positively than unfamiliarized drivers. However, familiarization decreased drivers’ self-confidence and did not prevent from haste when overtaking slow vehicles. We discussed the relevance of using a driving simulator in FCW’s studies and the possibility to transfer skills and knowledge to field operational tests. Finally, we proposed possible improvements to make the familiarization with the system still more effective.Introduire des systèmes avancés d’aide au conducteur dans le véhicule pourrait augmenter le confort des conducteurs et réduire le nombre d’accidents. Toutefois, des méthodes d’évaluations adaptées sont nécessaires à l’étude des interactions conducteur/système. Les systèmes d’aide génèrent effectivement des cas d’usage critiques, i.e. des situations ou les alertes, ou l’absence d’alertes, peuvent être négatives pour la sécurité. L’objectif de la recherche était d’évaluer l’impact de la familiarisation avec les cas critiques d’usage du Forward Collision Warning (FCW) sur simulateur de conduite. Nous avons testé l’hypothèse selon laquelle l’expérience du fonctionnement du FCW dans des situations critiques d’usage augmente la performance de conduite et la confiance des conducteurs dans le système. Nous avons comparé les jugements et la performance de conduite de trois groupes expérimentaux : un groupe contrôle où les conducteurs n’utilisaient pas le FCW, un groupe « non familiarisé » où les conducteurs utilisaient le système sans avoir été familiarisés et un groupe « familiarisé » où les conducteurs utilisaient le système après avoir été familiarisés. Les résultats montrent que la familiarisation rend les interactions conducteur/système plus efficaces et plus sûres. Par ailleurs, les conducteurs familiarisés ont des opinions plus positives sur le FCW comparé aux non familiarisés. Néanmoins, la familiarisation diminue la confiance des participants dans leur capacité de conduite. De plus, elle ne permet pas d’éviter que les conducteurs dépassent de façon trop précipitée les véhicules lents. Nous discutons la pertinence du simulateur pour l’étude du FCW et la possibilité de transfert des connaissances à la conduite sur route réelle. Finalement, nous proposons des améliorations pour rendre la familiarisation avec le système plus efficace

The Influence of Fog on Motion Discrimination Thresholds in Car Following

A possible explanation for close following in fog is that it would allow drivers to control headway more precisely by reducing motion perception thresholds. The purpose of our experiments was to determine the motion discrimination thresholds for closing and receding under normal and foggy conditions. An experiment and a pilot study were conducted on a driving simulator in which subjects were presented with a car following situation. Subjects had to press a button as soon as they detected that the lead vehicle was closing or receding, and their choice response time was recorded. Several visibility conditions were tested corresponding to different contrasts between the lead vehicle outline and the background, ranging from clear weather conditions to foggy conditions in which the vehicle could only be seen by its rear lights. Initial headway and lead vehicle acceleration were also varied. As expected, response times were longest with small accelerations and long headways. There was also an effect of visibility conditions with longer response times when the contrast between the vehicle outline and the background was 5% or less. Moreover, the reduction of response time corresponding to a reduction of headway was greater in fog than in clear conditions, at least in the given range of distances. This suggests that driving closer in fog may have a perceptual-control benefit in terms of a reduction in response times that partially offsets the reduction in timeheadway. Driving closer may also benefit lateral trajectory control because the lead vehicle is less likely to be lost in fog

Body movement strategies to initiate the crossing of a street in front of traditional and self-driving cars in young and older adults

International audienceBACKGROUND AND AIM: The safety of elderlies is a key societal issue, especially when considering that 48% of pedestrian fatalities involve people aged 65 or more (Sécurité Routière 2017-France). Aging affects street crossing behavior, with a decrease of walking speed or more risky decisions because elderly people have difficulties to estimate the approaching speed of vehicles, especially in complex situations. In young adults, recent work focused on body movement performed to initiate the crossing, showing a top down sequence of advancement along the antero-posterior axis: the head initiates the crossing movement, followed by the shoulders, elbows, wrists, hips, knees and ankles. Identifying such motion invariants can be particularly useful in the context of self-driving vehicles which aim at predicting the intent of crossing. In this study, we aim at investigating body movement strategies performed before crossing in older adults in complex mixed traffic. METHODS: 30 young adults (YA, 21-39yo) and 30 older adults (OA, 68-81yo) were asked to cross (or not) a virtual two-way street by walking in a simulator. Participants performed a total of 120 trials where we manipulated: the type of vehicles (Conventional and/or Self driving car, the latest always stopping to let the pedestrian cross the street), their speed (30 or 50km/h), their position on the lane (far/near lane), as well as the temporal gap available to cross the street (1,2,3,4 or 5s). After computing temporal body segment motion and orientations, we analyzed the delays in initiating the crossing movement for the head, shoulders and hips with respect to the feet. We also performed hierarchical clustering to identify specific groups of behavior. RESULTS: Preliminary results show a top-down sequence of forward body motion, starting from the head to the feet, whatever the traffic condition and the group. In OA, the head initiates the motion sooner than YA wrt their feet. Moreover, while the horizontal angle profile of the head, shoulders and hips does not allow to identify invariants due to the large variety of behaviors before crossing, the trunk tilt angle profile appears to be a relevant marker for predicting the intent to cross the street. CONCLUSIONS: While aging was shown to affect street crossing decisions, our results highlight consistent behavior between YA and OA regarding trunk tilt profile when initiating the crossing. In line with previous work on YA, we also show a top down sequence of advancement of body segments. Future work is needed to use our results to predict the intent of crossing on a new database. Beside the choice to cross the street, future work is also needed to understand body segment motion and walking speed profile while crossing

Dancing With Parkinson's Disease: The SI-ROBOTICS Study Protocol

Introduction: Parkinson's disease (PD) is one of the most frequent causes of disability among older people, characterized by motor disorders, rigidity, and balance problems. Recently, dance has started to be considered an effective exercise for people with PD. In particular, Irish dancing, along with tango and different forms of modern dance, may be a valid strategy to motivate people with PD to perform physical activity. The present protocol aims to implement and evaluate a rehabilitation program based on a new system called “SI-ROBOTICS,” composed of multiple technological components, such as a social robotic platform embedded with an artificial vision setting, a dance-based game, environmental and wearable sensors, and an advanced AI reasoner module. Methods and Analysis: For this study, 20 patients with PD will be recruited. Sixteen therapy sessions of 50 min will be conducted (two training sessions per week, for 8 weeks), involving two patients at a time. Evaluation will be primarily focused on the acceptability of the SI-ROBOTICS system. Moreover, the analysis of the impact on the patients' functional status, gait, balance, fear of falling, cardio-respiratory performance, motor symptoms related to PD, and quality of life, will be considered as secondary outcomes. The trial will start in November 2021 and is expected to end by April 2022. Discussions: The study aims to propose and evaluate a new approach in PD rehabilitation, focused on the use of Irish dancing, together with a new technological system focused on helping the patient perform the dance steps and on collecting kinematic and performance parameters used both by the physiotherapist (for the evaluation and planning of the subsequent sessions) and by the system (to outline the levels of difficulty of the exercise). Ethics and Dissemination: The study was approved by the Ethics Committee of the IRCCS INRCA. It was recorded in ClinicalTrials.gov on the number NCT05005208. The study findings will be used for publication in peer-reviewed scientific journals and presentations in scientific meetings