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

Comprendre et améliorer les décisions de traversée de rue des piétons âgés. Synthèse des travaux du LEPSIS

Note de synthèseNote de synthèse des travaux du Lepsis sur la question des piétons âgés proposée au concours Hand'Ensemble 2017 à Versaille

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

Street-crossing workload in young and older pedestrians

Although several studies have sought to identify both gap-acceptance difficulties with aging and gait differences, few have examined the extent to which crossing the street is physically and cognitively demanding for older pedestrians, in such a way that street crossing can be seen as a dual task. To gain insight into this issue, this study reports an experiment with 15 young (ages 19-26), 19 younger-old (ages 60-72), and 21 older-old (ages 73-82) adults. The participants carried out three tasks: (i) a simple walking task, (ii) a dual task involving walking while scanning (walking while pressing a button as soon as a visual or sound stimulus appeared), and (iii) a streetcrossing task with vehicles approaching from two directions. The results indicated more street-crossing collisions in older-old than in younger-old and young participants. Longer reaction times were observed in the dual walking-scanning task for both old groups, especially for visual stimuli. Walking-speed comparisons yielded nonsignificant differences between the dual task and the street-crossing task in young participants, suggesting a correspondence in terms of demands and task priority. In contrast, old participants walked significantly faster in the street-crossing task than in the dual task, suggesting that they placed priority on walking rapidly than on scanning traffic. Finally, whereas the participants estimated the perceived workload to be greater when they were crossing the street than while simply walking or responding to the dual task, young participants gave the highest rating to the mental and physical demands, perhaps due to a lack of awareness of task demands among old participants

Sécurité et mobilité des usagers âgés de la route : impacts des déclins cognitifs et possibilités d’entraînement

La conduite et la marche à pied sont essentielles à la promotion de l’indépendance et du bien-être des personnes âgées. Pourtant, les statistiques d’accidentologie, tant nationales qu’internationales, montrent que les conducteurs et piétons âgés représentent une catégorie d’usagers de la route particulièrement vulnérable. L’objectif du projet européen SaMERU (Safer Mobility for Elderly Road Users) est de dresser l’inventaire des connaissances scientifiques quant à l’impact du vieillissement sur la sécurité du déplacement et de la mobilité, mais également de recommander des actions afin de diminuer les risques d’accidents. Les programmes d’entraînement visant à réduire ou compenser certains déclins cognitifs avec l’âge sont une de ces possibilités d’actions. L’objectif de cette communication est de proposer un panorama (i) des connaissances actuelles sur la relation entre déclins cognitifs et sécurité des comportements des usagers âgés de la route, et (ii) des différents types d’entrainement qui ont été mis en place. Le déclin lié à l’âge de plusieurs capacités cognitives est susceptible de réduire la sécurité des conducteurs et piétons. De nombreuses études suggèrent que le risque d’accidents est plus grand chez les conducteurs âgés présentant une altération de la vitesse de traitement, de l’attention, des fonctions exécutives, de la mémoire, ou bien encore de la prise de décision. Bien que moins nombreuses, les études sur les piétons âgés suggèrent que le risque d’accident est lui aussi augmenté lorsque l’une de ces fonctions est altérée. L’entraînement cognitif ainsi que les programmes alliant exercices physiques et cognitifs montrent des résultats prometteurs pour améliorer la sécurité des conducteurs âgés. Moins étudiés, les piétons âgés font maintenant l’objet de plus nombreuses études et des programmes d’entraînement commencent à être proposés. Un effort futur devra aussi être porté sur les cyclistes et usagers âgés des transports en commun

Strategy and accuracy during information search on the Web: Effects of age and complexity of the search questions

International audienc

Adapting a pedestrian navigation simulator to the elderly

European Conference in Cognitive Ergonomics, Nottingham, ROYAUME-UNI, 06-/09/2016 - 08/09/2016Virtual environments are nowadays broadly used in scientific research about spatial navigation. To ensure the validity of the navigation experiment as well as the safety of the participants, human factors should be taken into account while designing the device. In particular, older participants may face difficulties while navigating a virtual environment due to age-related declines. This paper presents two studies aiming to adapt a pedestrian navigation simulator to the elderly specificities.Les environnements virtuels sont aujourd'hui largement utilisés dans les recherches scientifiques sur la navigation spatiale. Pour assurer la validité de l'expérimentation tout comme la sécurité des participants, les facteurs humains doivent être pris en compte lors de la conception des simulateur. Les personnes âgées, en particulier, peuvent rencontrer des difficultés sur simulateur de navigation, du fait de déclins liés à l'âge. Ce poster présente deux études visant à adapter un simulateur de navigation piétonne aux spécificités des plus âgés

What Sensory Pedestrian Navigation Aids For The Future?

International audienc