Effects of Time of Day and Sleep Deprivation on Motorcycle-Driving Performance

The aim of this study was to investigate whether motorcycle handling capabilities – measured by means of the efficiency of emergency manoeuvres – were dependent on prior sleep deprivation and time of day. Twelve male participants voluntarily took part in four test sessions, starting at 6 a.m., 10 a.m., 2 p.m., and 6 p.m., following a night either with or without sleep. Each test session comprised temperature and sleepiness measurements, before three different types of motorcycling tests were initiated: (1) stability in straight ahead riding at low speed (in “slow motion” mode and in “brakes and clutch” mode), (2) emergency braking and (3) crash avoidance tasks performed at 20 kph and 40 kph. The results indicate that motorcycle control at low speed depends on time of day, with an improvement in performance throughout the day. Emergency braking performance is affected at both speeds by time of day, with poorer performance (longer total stopping distance, reaction time and braking distance) in the morning, and also by sleep deprivation, from measurements obtained at 40 kph (incorrect initial speed). Except for a tendency observed after the sleepless night to deviate from the initial speed, it seems that crash avoidance capabilities are quite unaffected by the two disturbance factors. Consequently, some motorcycle handling capabilities (stability at low speed and emergency braking) change in the same way as the diurnal fluctuation observed in body temperature and sleepiness, whereas for others (crash avoidance) the participants were able to maintain their initial performance level despite the high levels of sleepiness recorded after a sleepless night. Motorcycle riders have to be aware that their handling capabilities are limited in the early morning and/or after sleep deprivation. Both these situations can increase the risk of falls and of being involved in a road accident

Different forms of attentional disturbances involved in driving accidents

Attentional processes are necessary for any complex activity, such as driving. When a driver's attention is not optimal, driving errors can arise. The aim of this study is to highlight the involvement of attentional problems and their weight in accident production, using data from in-depth accident analyses. Three attentional disturbances are distinguished according to the task that competes with the driving activity: inattention, attention competition and distraction. Inattention is the defect most frequently represented (74%) compared with attention competition (18%) and distraction (8%). Overall, attentional disturbances mainly lead to detection failures (44.7%). In more than half of the cases, other factors are required for a driving error to emerge. The interest of studying human failures linked to attentional disturbances is that it provides a definition of driver's needs in terms of assistance, thus identifying which systems are the most relevant and, on the contrary, which might reduce the attention capacities required for driving

As beautiful as the woman in Ancient Rome : an overview of the Raman studies on cosmetic powders from Pompeii

White for the face, black for the eyes and red for the lips and the cheeks, there are the principal colours used by the women of the ancient Mediterranean world to makeup themselves, as confirmed by the description of the habits given by Ovid1 or Tertullian2. But what about the materials used? A multi-analytical approach for the study of cosmetics samples from the ancient Greek and Roman worlds enlighted us about the diversity of materials used3,4.We propose here to focus on Raman and SERS results obtained on pompeian samples to show the complexity of the formulation of roman cosmetic powders

Les défaillances d'interaction dans les accidents impliquant un deux-roues motorisé. Rapport scientifique Tâche 1 (R1)

Rapport de rechercheCe projet a pour ambition d'identifier les différentes facettes de l'insécurité des DRM : du point de vue de l'usager DRM, du point de vue des autres usagers et du point de vue de l'infrastructure routière. Il s'appuie sur trois approches complémentaires : L'analyse des accidents de deux-roues à partir de données EDA (Etudes Détaillées d'Accidents) et d'exploitations de procédures (Procès-Verbaux) ; L'analyse comportementale des situations de conduite en deux-roues en interaction avec les autres usagers ; L'analyse des représentations réciproques des usagers de deux-roues et des autres usagers.ANR / Predit / Projet "2RM" 2006-2008 : Accidentologie, Usage et Représentation des Deux-Roues Motorisés. Partenariat : INRETS-MA, LAB-GIE PSA/Renaul

Analyse approfondie de l'accidentologie en aménagements urbains : erreurs, facteurs et contextes de production

convention INRETS/DSCR N° 02-70-028 Etude N°2Rapport de rechercheL'aménagement constitue à la fois le support physique des déplacements et la grille de lecture des événements qui s'y déroulent. Son adaptation à ses utilisateurs conditionne de manière non négligeable les comportements qu'ils mettent en oeuvre, notamment dans la ville. Les politiques de gestion de l'urbanisme ont évolué depuis une vingtaine d'années et tentent aujourd'hui d'intégrer et de satisfaire de nombreuses préoccupations (sécurité, qualité de vie, etc.). Cependant, les accidents en milieu urbain restent importants, que ce soit par leur nombre ou par leur gravité. L'objectif de cette étude est de chercher à identifier ce qui caractérise ce type d'accidents, afin de mieux en comprendre les mécanismes et les spécificités par rapport aux accidents ayant lieu en rase campagne. L'accent est mis sur les difficultés auxquelles les usagers de la route et de la ville sont confrontés, ainsi que sur les répercussions de ces difficultés dans leur activité en situation critique. Les résultats mettent en évidence des différences sensibles dans les processus fonctionnels défaillants dans la ville et en dehors. Une analyse des facteurs et des contextes de production des "erreurs humaines" dans la ville permet ainsi d'expliquer certains fondements de l'accidentalité urbaine. Ce travail est fondé sur les Etudes Détaillées d'Accidents réalisées à l'INRETS-MA