Analyse ergonomique de l’activité de conduite moto lors de la pratique de l’inter-files en région parisienne

Cet article présente une analyse en contexte naturel des comportements de conduite de motocyclistes lors de leurs trajets domicile-travail en région parisienne. Elle se focalise sur la pratique des motards qui consiste à circuler entre les files de voitures, classiquement appelée « inter-files », et qui reste pour l’heure sans analyse scientifique approfondie. Dans une approche ergonomique, 11 motocyclistes ont conduit pendant un mois avec un véhicule équipé de caméras. Les enregistrements vidéo ont permis la description des contextes de conduite ainsi que la tenue d’entretiens d’auto-confrontation. Les résultats portent sur la description de leur activité de conduite, le poids de l’inter-files dans leurs déplacements quotidiens et l’analyse des éléments organisateurs de leurs comportements. Ces résultats sont discutés sur le plan de la compréhension de la pratique de l’inter-files et sur le plan de l’enrichissement des situations existantes : ils questionnent la possibilité d’une législation sur les remontées de files et montrent les intérêts de la formation à cette pratique.This paper presents a naturalistic study of how motorcyclists behave whilst commuting in the Paris region. The study focuses on lane-splitting which consists in riding between traffic lanes. This phenomenon has never been subjected to any detailed scientific analysis. In an ergonomic study, for one month 11 motorcyclists drove a motorbike equipped with cameras. The video recordings and the conduct of self-confrontation interviews enabled the description of the driving contexts. The results concern the description of the motorcyclists’ activity, the importance of lane-splitting in their daily journeys, and the study of the organizing elements of their behaviors. These results are discussed in terms of a better understanding of lane-splitting and in terms of the improvement of the existing situations: the data question the possibility of a law regarding this practice and demonstrate the utility of training

Approche ergonomique de l’usage du régulateur de vitesse conventionnel : analyse critique de la littérature scientifique

Cet article propose une revue critique de la littérature scientifique disponible sur l’usage du régulateur de vitesse « conventionnel » (CCC pour Conventional Cruise Control). Ce système d’assistance à la conduite, qui prend en charge le maintien de la vitesse du véhicule, intègre progressivement l’ensemble des gammes de modèles automobiles. L’analyse de la littérature permet (1) de mettre en évidence les effets positifs identifiés du CCC sur l’activité de conduite et les problèmes liés à son utilisation, (2) de souligner le manque d’études systématiques de type ergonomique sur son usage, malgré les efforts des équipementiers et des constructeurs automobiles pour diffuser ce dispositif sur l’ensemble des segments du marché, (3) d’identifier des perspectives d’enrichissement de ces études aux niveaux de la dimension individuelle-collective de l’usage du régulateur, des conditions de recueil des données laboratoire-situations réelles, et du caractère statique-dynamique de l’appropriation du CCC. Ces perspectives tirent profit de la maturité des recherches sur le « régulateur de distance » (ACC pour Adaptive Cruise Control), version évoluée du modèle conventionnel qui a, lui, donné lieu à une littérature scientifique plus riche malgré son apparition récente.This article offers a critical analysis of existing scientific literature on the use of conventional cruise control (CCC). This driver assistance system, which maintains a speed pre-set by the driver, is gradually being incorporated into all passenger cars in France. This review makes it possible to (1) determine the benefits and drawbacks of CCC for drivers, and the problems related to its use, (2) pinpoint the lack of systematic ergonomic studies concerning CCC use, despite the efforts of cruise control designers and car manufacturers to introduce the device in all market segments, and (3) suggest ways this research could be improved as regards the individual-group aspect of cruise control use, the conditions in which data are collected in both laboratory and real-life situations, and the static-dynamic aspect of learning to use CCC. This review has benefited from the latest advances in research into adaptive cruise control (ACC), a recent development of CCC, which in the short time since it was launched has already given rise to a large amount of literature

Former à la conduite moto

Les motocyclistes novices constituent une population vulnérable en termes de sécurité routière. Les efforts scientifiques pour comprendre les phénomènes associés à cette population sont encore limités. L’étude présentée porte sur la formation initiale à la conduite de motocyclette et repose sur deux hypothèses fondatrices : l’optimisation de la formation à la conduite permet de réduire l’accidentalité et la connaissance des contenus réellement enseignés peut faire évoluer la formation. Les contenus d’enseignement ont été analysés systématiquement au cours d’une étude menée en situation réelle de formation. Des observations et verbatim ont été recueillis pour l’ensemble de la formation d’un motard et complétés par des observations menées dans trois autres écoles de conduite. Les résultats montrent la relative pauvreté des situations observées : la survalorisation de l’enseignement d’habiletés « fermées » au détriment d’habiletés de conduite plus « ouvertes », la focalisation sur des habiletés rarement mobilisées en situation de conduite réelle et la répétition à l’excès des situations d’examen. Des pistes d’amélioration de la formation initiale sont proposées en discussion.Novice motorcyclists are vulnerable people as regards road safety. The scientific efforts made to understand the phenomena associated with that group of people are still limited. The study herein focuses on initial motorcycle training and is based on two founding assumptions: optimizing riding can reduce accident hazards, and studying what is really taught can lead to better training courses. The teaching content has been systematically analyzed as part of a study made from real teaching situations. Observations and remarks have been gathered all through the motorcycle rider training and completed by observations done in three other driving schools. The results show the relative poverty of the observed teaching situations: overrating the teaching of ‘closed’ skills to the detriment of more ‘open’ riding skills, focusing on skills that are rarely used when riding a bike, and repeating exam situations to excess. Ways to better the initial training are suggested for discussion.Die Fahranfänger bilden in Sachen Verkehrssicherheit eine verletzbare Gruppe. Die wissenschaftlichen Anstrengungen, um die mit dieser Gruppe verbundenen Erscheinungen zu verstehen, sind noch begrenzt. Vorliegende Forschungsarbeit befasst sich mit der Erstausbildung zum Motorradfahren und beruht auf zwei Gründungshypothesen: die Optimierung der Fahrausbildung kann erlauben, die Unfallquote zu senken und die Analyse von dem, was wirklich unterrichtet wird, kann erlauben, die Ausbildung zu verbessern. Die Unterrichtsinhalte wurden bei einer reellen Ausbildungssituation systematisch analysiert. Beobachtungen und die worttreue Wiedergabe wurden für die gesamte Ausbildung eines Motorradfahrers gesammelt und durch in drei anderen Fahrschulen gemachte Beobachtungen ergänzt. Die Ergebnisse zeigen den relativen Mangel an beobachteten Ausbildungssituationen: die Überbewertung des Unterrichts von „geschlossenen“ Geschicklichkeiten auf Kosten „offener“ Fahrgeschicklichkeiten, die Zentrierung auf Geschicklichkeiten, die in reeller Fahrsituation selten mobilisiert werden und die im Überma wiederholten Prüfungssituationen. Verbesserungsmöglichkeiten der Erstausbildung werden vorgeschlagen.Los motoclistas novatos constituyen una población vulnerable en términos de seguridad por carretera. Los esfuerzos científicos para entender los fenómenos asociados a esta población siguen siendo limitados. El estudio presentado aquí concierne la formacón inicial a la conducción de motocicleta y descansa sobre dos hipótesis fundadoras: la optimización de la formación a la conducción puede permitir reducir la accidentalidad y el estudio de lo que realmente se enseña puede permitir mejorar la formación. Los contenidos de enseñanza han sido analizados sistemáticamente durante un estudio realizado en situación real de formación. Unas observaciones y verbatim han sido recogidos relativamente al conjunto de la formación de un motorista y completados por informaciones realizadas en otras tres escuelas de conducción. Los resultados evidencian la relativa pobreza de las situaciones de formación observadas: la sobrevaloración de la enseñanza de habilidades « cerradas » en detrimento de habilidades de conducción más « abiertas », la focalización sobre habilidades realizadas con poca frecuencia en situación de conducción real, y la repetición excesiva de situaciones de exámenes. Se propone discutir sobre algunas pistas para mejorar la formación inicial

Case study of the real contents delivered in French motorcycle schools

This study is concerned initial motorcycle training delivered in motorcycle schools in France. Novice motorcyclists are a particularly vulnerable group of road users in Europe and in France. However, scientific attempts to achieve a better understanding of their behaviors have been limited. The potential value of studying initial motorcycle training, both for research purposes and with regard to public policy, is readily apparent. The aims of this paper are to describe the real educational content of training in motorcycle schools and analyze to what extent this content is related to riding after licensing. A case study of all the training process of one trainee (38 hours) was carried out in real world. Audiovisual recordings and interview data of the rider and instructors were collected at each session. This study was supplemented by ethnographic observations of the educational content provided in three motorcycle schools throughout the instructors’ working days. The results that merged from both studies show (1) the riding skills that were fostered (i.e. control skills, and especially emergency skills, in stable and restricted environments) and undervalued (i.e. hazard perception skills, everyday skills) during initial training, and (2) the poverty of observed training settings: learners spend almost all their training time riding in the same setting that is used in the test. In addition to being repeated to excess, these settings are quite different from the real traffic. These results are discussed regarding the scientific literature on motorcycle education. The conclusion presents the implications of these results for public policy in order to design a future rider training system. Document type: Articl

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R[superscript Δ] with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.National Science Foundation (U.S.) (Grants 1455202 and 1551980)Wyle Research (Firm) (Grant 2014/T72497)United States. National Aeronautics and Space Administration (NASA Earth and Space Science Fellowship Grant HELIO15F-0005

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

International audienceA precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio inprimary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particlesin cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, protonp, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− fluxexhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios eachreaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigiditydependence. These are new observations of the properties of elementary particles in the cosmos

Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4 × 106 nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GVand all three fluxes have an identical rigidity dependence above 30 GV with the Li=Be flux ratio of 2.0 $\pm$ 0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays

Observation of Fine Time Structures in the Cosmic Proton and Helium Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

International audienceWe present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of $1 \times 10^9$ events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above $\sim 3$  GV the p/He flux ratio is time independent. We observed that below $\sim 3$  GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law RΔ with index Δ = −0.333 +/- 0.014(fit) +/- 0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ = −1/3 asymptotically.</p