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In recent years, the role of "sleepiness at the wheel" in the occurrence of accidents has been increasingly highlighted with several national and international public health campaigns based on consensual research publications. However, one aspect of this phenomenon is rarely taken into account, i.e., the risk of sleep-induced accidents while riding powered two-wheelers (PTWs). PTWs are indeed involved in a high percentage of fatal accidents mostly with young male riders. The effects of sleepiness may be different in drivers and riders, partly because riders may be stimulated more by the road environment. But riders (differently from drivers) have also to maintain continuously a balance between their own stability and the need of following the road, even when they are directly exposed to adverse climatic conditions. We, therefore, gathered the limited scientific literature on this topic and tried to analyze how riders may be affected differently by sleepiness. Finally we provide some suggestions as to how this question may be better approached in the future.

Background: Noise in the vicinity of airports is a crucial public health issue. Exposure to aircraft noise has been shown to have adverse effects on health and particularly on sleep. Many studies support the hypothesis that noise at night can affect subjective sleep quality. Fewer studies, however, have performed objective measurements of sleep. Objectives: The aim of the present study was to investigate the relationship between aircraft noise exposure and objective parameters assessed by actigraphy of sleep quality in the population living near two French airports. Methods: This study includes 112 participants living in the vicinity of Paris-Charles de Gaulle and Toulouse-Blagnac airports. Wrist actigraphy measurements were performed during eight nights to evaluate objective parameters of sleep quality such as sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), time in bed (TB) and sleep efficiency (SE). Acoustic measurements were made simultaneously both inside the participants' bedrooms and outside (at the exterior frontage) in order to estimate aircraft noise levels. Energy indicators related to the sound energetic average for a given period of time, as well as indicators related to noise events (such as the number of events that exceed a given threshold for example) were estimated. Logistic and linear regression models were used, taking into account potential confounders: age; gender; marital status; education; and body mass index (BMI). Results: Energy indicators, and more particularly indicators related to noise events, were significantly associated with objective parameters of sleep quality. Increased levels of aircraft noise and increased numbers of aircraft noise events increased the time required for sleep onset (SOL) and the total wake time after sleep onset (WASO), and decreased sleep efficiency (SE). An association was also observed between aircraft noise exposure and an increase in total sleep time (TST) and time in bed (TB). Conclusion: The findings of the present study contribute to the overall evidence suggesting that nocturnal aircraft noise exposure may decrease objective quality of sleep. Aircraft noise exposure affects objective parameters of sleep quality, not only in terms of noise levels but also in terms of number of events. Mechanisms for adapting to sleep deprivation could be observed.

International audience; This paper analyses motorcycle educational content in a number of French motorcycle schools on the basis of a naturalistic study of riders' and trainers' behaviour. The aim is to specify the situations delivered in motorcycle schools and to study the rider's activity in these situations. The methodology includes ethnographic observation within the motorcycle schools and the longitudinal monitoring of 14 trainee motorcyclists during their initial training. The training situations were described by the combination of audio-visual recordings and interviews data (i.e. concomitant or interruptive verbalization, and self-confrontation data). The results permit to (1) compare the "real" and "official" durations of track and on-road training, (2) characterize the real training situations, (3) describe the preferred forms of instruction, and (4) conduct an in-depth analysis of the situations used during training in traffic. The discussion show, in first, the poverty of the training situations which are based on the repetition of the exercises in the test, and, in second, disparities between the riding situations encountered during training and the demands made by riding in natural traffic. The usefulness and the applications of this type of approach - based on the integration of the rider's point of view notably by self-confrontation interview - for understanding real riding behaviours and how such approaches could supplement vehicle-based data are discussed in a large conclusion.