Analyse qualitative des pratiques pédagogiques des enseignants de la conduite et de l’effet de l’expérience du métier

The first stage of the EPEC research (2007–2010) presented in this article enables to know better driving teachers’ pedagogical practises. We have thus observed 26 subjects, 13 experienced driving teachers and 13 novice driving teachers in real training situations, during their theoretical and practical lessons. The analysis of their practises enables to suggest pedagogical changes. The results concern mainly the theoretical and practical lessons as well as the choice of complex situations. These results enable us to prepare the second stage of this research: the construction of remediation exercises with driving teachers intended for learners in difficulty.     

Évolution des émissions de CO2 liées aux mobilités quotidiennes: une stabilité en trompe l’œil

Alternatives to the use of automobiles have regained attention at the urban level. Against this background, we look at the spatial context of this attention in the agglomeration of Lyon. More specifically, we look at how CO₂ emissions that are associated with everyday mobility have developed until recently. First, we estimate the intensity of CO₂ emissions per day based on the last two household travel surveys done in the Lyon conurbation in 1995 and 2006. Even if the global emission level remains stable, we aim to analyze the dynamics of the socio-economic evolution of mobility between the two periods. To that end, we have abstracted the linkage of a specific form of mobility (mode of transport and distance) to a specific population group (status, residential location, car access, gender). This typology helps us highlight the groups where emission rates are significantly higher, and where the focus on emission reduction should be intensified.     

Vieillissement et gravité des atteintes lésionnelles des victimes d’accident de la circulation routière

This study uses the road traffic accident casualty register for the Rhône Département to investigate how the risk of severe or fatal injury varies according to age and to describe the injuries that explain the severity. Two groups of road users are investigated, car occupants and pedestrians. A NISS score of nine or over is taken to indicate a severe injury. Data analysis reveals that, for both groups, the risk of severe or fatal injury increases with age. The nature and location of the injuries depend on the age and sex of the victims. With regard to severe injuries, elderly female pedestrians are susceptible to fractures of the femur (and the femoral neck) and all parts of the upper limbs. Elderly male pedestrians are mainly exposed to fractures of the femoral neck. The greater vulnerability of severely injured elderly drivers results in thoracic injuries, which are partly explained by seat–belt wearing. The main cause of death, for pedestrians of all ages and young drivers is severe head injuries. Car occupants over the age of fifty more frequently suffer from severe thoracic injuries. These findings should not, however, be allowed to conceal the differences observed in the general population for the two severity criteria we have analyzed (severe injury or death). Mortality (in relation to the general population) is highest for young car occupants, while lethality (the fatality rate amongst those injured) is highest among the elderly. For pedestrians, both mortality and lethality increase with age. These findings are also applicable to the risk of severe injury. They justify the continuation of passive safety research in order to develop protection systems that are appropriate for the characteristics of car occupants. Furthermore, they should help to increase everybody’s awareness of the vulnerability of pedestrians and stimulate the introduction of preventive measures, particularly for seniors.     

L'information sur les durées de parcours: Modélisation de l’activité cognitive impliquée

In recent years some urban express roads have been equipped with journey time information systems, which are greatly appreciated by drivers. It has been observed that the messages help drivers take appropriate decisions and then better manage the time they spend travelling and deal better with congestion. In order to understand why the content of the messages leads to the behaviour in question we have developed a hypothetical architecture for the mental process demanded by the messages. This paper presents the cognitive model we have developed, which is based on knowledge networks.     

Évaluation des potentiels de réduction des trafics automobiles dans le cas de la zone dense francilienne

The Pari 21 research project does not attempt to justify a move towards a radically different system—practically everything there is to say about the benefits and disadvantages of cars in cities has already been said. Instead, the project will perform simulations and assess, from the point of view of individuals, the feasibility of a transport system that is based mainly On the use of modes Other than the private car in the densely populated zone Of the Greater Paris Area (Paris city plus the inner suburbs). By constructing and evaluating transport policy scenarios, this research also aims to measure the potential for reducing car use in highly urbanized zones, particularly that which results from the reduction in journey speeds which are a likely consequence of the policies in question The method is based on repeated iterations of a simulation model which combines the assignment of round trips to modes other than the automobile with reformulations of transport supply. Demand is channelled towards personal modes (walking, cycling), public transport and a combination of personal and public modes. These iterations are based on the 1991-1992 Paris Region comprehensive travel survey which recorded all the round trips by car made in a typical day by the individuals living in the zone (i.e. the sequence of all trips made between each time the individual leaves home and returns home).     

Estimation des impacts atmosphériques des projets de gestion de trafic : de l’application des modèles théoriques sur des cas concrets

In addition to its harmful economical and social effects, road traffic congestion is a key contributor of emissions of CO₂ and local pollutants. Many traffic management policies could be implemented to tackle it. However, the impacts of those strategies on air quality and greenhouse effect are poorly predicted by classical assessment procedures. Indeed, current assessment tools are based on aggregated traffic data, which fail to capture the dynamic effects of traffic management policies on traffic flow. This article presents an estimation tool capable of measuring all the effects of traffic management policies. It is based on a commonly used dynamic traffic flow model (AIMSUN) combined with different emission models, in order to identify modelling features leading or not to differences in results. Different models combination have been applied and compared for two traffic regulation strategies: a HOV lane dedicated only to buses and taxis created on the leftmost lane of A1 between Charles de Gaulle airport and Paris, and a reduction of speed limits on a section of motorway A86 in the northwest of Paris. Substantial differences in predictions of different emission models are highlighted. They cannot be entirely explained by differences in emission laws. Other insights with regard to traffic representation and emission models?? inputs are also investigated to explain them.     

L'influence de la biactivité sur les stratégies spatiales des ménages

A survey conducted among staff at the University of Paris xii Val-de-Marne has shown that there are considerable differences in residential location and commuting strategies between those in one income households and those in two income households. This difference varies depending on social group. In the case of higher social groups, being in a two income household as opposed to a one income household increases the range of residential possibilities rather than the household's income per consumer unit, and in particular allows them to live nearer their work. In contrast, for low income groups, working couples commute considerably greater distances than persons in one income households. Thus, for lower income groups, belonging to a working couple mainly provides greater opportunities for home ownership, as an increase in distances to work does not affect journey times.     

VirMaLab — atelier virtuel de maintenance: un outil d’aide à la décision pour l’optimisation des politiques de maintenance

This article deals with a generic approach called VirMaLab (virtual maintenance laboratory) for reliabilitybased maintenance modeling for complex systems (with multi-components and multi-states). Based on the probabilistic graphical models formalism (also known as Bayesian networks), this stochastic approach takes into account both the degradation process of the considered system (an original semi-Markovian model is proposed) and maintenance strategies (from diagnosis factors to all kinds of maintenance actions). For complete decision support tools, cost parameters should also be considered (maintenance actions, unavailability of the system, running, etc.). In this article, two applications of this approach to rail maintenance are introduced. The first one focuses on the optimization of the compromise refurbishment/repairing of central part of the RER A line. The second one focuses on the comparison and evaluation of various maintenance strategies in the modernization of the command control systems of Paris metro lines.     

Les enseignements de l’expérience corse en matière de continuité territoriale : des exigences fortes en termes de régulation et de gouvernance

The Corsican territorial continuity system is 35 years old. Overall, it has allowed a significant improvement in communications between the island and the mainland of France. It has also actively contributed to the economic development of the island. But its economic and financial balance is far from perfect. Especially, its collective cost seems excessive. The failures can be identified at two levels: at the territorial governance level and at the regulation level.     

Évaluation des logiciels critiques: application à la méthode B

From the point of view of safety the bottleneck in the operation of computerized systems currently appears to be the software. In order to improve the safety of software an independent assessment of its quality has been advocated for several years. The assessment of safety critical software consists of a technical examination on the basis of a set of criteria by a body which is independent from the designer. These assessment criteria are derived from the standards which are in force, the state of the art and experience. The objective of an assessments to verify that the product meets the specified safety and functionality requirements. In this paper the authors describe a combined approach to the assessment of safety critical software. On the one hand, the process used in order to develop the software is examined, and on the other the quality of the end product (software) is checked. The first part of the paper will present the position of safety critical software in the context of railway standardization as well as the main assessment techniques with particular reference to that used at Inrets. The second part of the paper will deal with the contribution of formal methods such as the B method to the development of safety critical software. The software assessment aspect will pay particular attention to assessment of the product — analysis of the traceability of requirements, integration and validation of safety properties. The paper ends with a brief account of the extraction and interpretation of metrics for a formal development. Finally the criteria used to assess the process are rapidly described. This approach has been used in the framework of an Esprit project known as Cascade (Certification and Assessment of Safety Critical Application Development).     

Les facteurs d’accidents de la route par somnolence chez les conducteurs âgés: Prévention par l’activité physique

Sleepiness while driving is a frequent factor in car crashes and the primary cause of fatal accidents on French motorways, particularly among the elderly. The ageing process is accompanied by chronobiological disturbances which affect diurnal vigilance in particular and may have an impact on driving. The quality of nocturnal sleep diminishes among the elderly and sleep takes the form of a number of short, increasingly frequent naps during the day. All the changes in nocturnal sleep are accompanied by changes in circadian rhythms, the most striking of which is a reduction in amplitude. To counteract the effects of ageing, we have investigated the extent to which regular moderate physical activity can have a beneficial effect on circadian rhythms and the quality of sleep. Our study shows that such activity results in a subjective and objective improvement in the quality of sleep and restores circadian rhythms. There is also an improvement in driving performance on a simulator.     

Intérêt du modèle ? Hurdle ? pour la comparaison des comportements de mobilité déclarée dans un protocole d’enquête mixte

Due to decline in response rate to household travel surveys, it is essential that survey methods research explore the use of mixed-mode surveys. With this in mind, the Laboratoire d??économie des transports (Transport Economics Laboratory) conducted a web-based survey on non-respondents to a face-to-face household travel survey administered in the Lyon urban area in 2005?C2006. Comparative analysis of the figures shows that, overall, face-to-face respondents travel more than web-based respondents. This difference is partly explained by a high proportion of individuals who did not travel on the survey reference day and also by a lower trip level for those who travel. Classical regression methods can explain the individual mobility level with individuals socioeconomic characteristics, but do not take account of individuals who did not travel during the survey reference period. Using two econometric methods (simple Poisson and Hurdle Poisson regression) we examined factors affecting the decision to travel on one hand and the level of mobility on the other hand. This involves estimating the average daily mobility of individuals as a function of their socioeconomic characteristics while taking into account the fact that for a considerable part of the survey population, daily mobility is nil. Our approach intends firstly to define the causes of immobility better and secondly to characterise the mobility level with the help of a Hurdle model, so as to compare the results obtained in the web-based and faceto-face samples.     

La place des modèles de trafic dans les récentes modélisations des impacts environnementaux des transports. Importance de l’explicitation des méthodes et hypothèses

The authors present a recent development in the use of classic travel demand models (TDMs) to environmental impact assessment of transport, far from its initial target. By comparing previous cases found in the literature (Chester, Seoul, Florence, Brisbane and Saint-Etienne) with their present works (Eval-PDU in Nantes), the authors notice that their predecessors tend to be evasive on their use of TDM. Hence, traffic data are little discussed in these works, while their works constitute one of the main stakes in this kind of study. Indeed, the hypotheses for traffic modeling are impacting the next steps of the modeling chain (pollutants emission/dispersion). The importance of this first modeling stage implies that relevant attention has to be brought to their assumptions and input data.     

Prospective de la mobilité en Île-de-France Les apports et les limites d' une démarche économétrique

The author has used econometric equations to forecast travel by car and public transport in the Paris Region in the year 2020. The parameters of the equations were estimated on the basis of the observed trends since 1980. The technique is innovative in that it takes account of changes in structural factors (distribution of population by age, ring zone of residence and car ownership) using what are termed structural demand variables. Existing forecasts of these structural factors have been used. By applying hypotheses about changes in the remaining explanatory variables (income, transport price and supply) we have estimated traffic levels in a business as usual scenario whose sensitivity to the explanatory factors has also been tested. From this we have derived some additional indicators: network congestion, trip frequencies for each mode, travel time and aggregate quality indicators. Finally, some limits of this approach are discussed.     

Différences de sexe et rôle de l’internalisation des règles sur la propension des enfants à prendre des risques à vélo

The objective of this study is to explore gender differences and effect of internalization of traffic rules on children’s propensity to take risks as cyclists. Risk perception, internalization of traffic rules, and self-reported risk-taking propensity as cyclist were measured in a questionnaire among 145 children (86 boys and 59 girls) aged 9 to 12. The results show gender differences in cycling rules internalization, risk perception, and risk-taking propensity as cyclist. Furthermore, the results show that internalizing traffic rules is a better predictor than biological sex of the propensity to take risks as cyclist.     

Enjeux de la mise en accessibilité des transports publics: le rôle de la maîtrise d’usage et de la coproduction

Since the act of February 11, 2005, the policy objective is to make urban projects accessible for all. This political context is strengthened on one hand by a greater social demand relieved by associations, and on the other hand by the need to anticipate the consequences of ageing population. A qualitative survey conducted in the metropolitan areas of Paris and Grenoble, with representatives of associations, transport operators, communities, and experts, shows that the law is not enough. The issue of a successful accessibility lies particularly in the political will at local level and in the involvement of people to overcome flaws in local projects, through consultation and coproduction initiatives. The users’ knowledge makes the project evolving and adapting according to social demand. The user has an expertise gained from his experiences that no one can match. Therefore, it has a vital role in the development, implementation and evaluation of projects’ accessibility.     

Réflexions sur le transfert méthodologique de l’analyse qualitative d’accidents de la circulation routière issue de l’étude détaillée des accidents (EDA) fran?aise aux procédures d’accidents colombiennes

Nearly 90% of the traffic accidents that occur worldwide happen in developing countries. Yet road safety remains a little-studied subject in these countries, and notably accidentology studies, which provide a wealth of information. One of the major problems in studying road accidents in developing countries lies in the lack of reliable accident data. Indeed, while the comprehensive accident analysis methodologies used in developed countries provide an understanding of the origin of accidents and accident processes, as well as making it possible to define suitable, effective actions, they require reliable and relatively detailed accident data. These methodologies are notably based on detailed accident studies (DASs) and their adaptation to the analysis of accident reports. Colombia has an infrastructure for gathering and storing traffic accident data that can be used to perform comprehensive accident analyses. This article defines the feasibility of a technology transfer (clinical accident analysis) to the Colombian equivalent of accident reports. These observations are part of a doctoral thesis prepared jointly by the IFSTTAR Accident Mechanisms Research Unit and the University of the Andes in Bogotá.     

Proximité aux infrastructures et croissance de l’emploi en ?le-de-France (1993–2008) : le r?le des transports à l’échelle intramétropolitaine

This article aims to analyze the role of proximity to transport infrastructures in employment growth within 291 municipalities located in the ?le-de-France region between 1993 and 2008. Based on the employment data from Unistatis, a multiple regression econometric model is estimated, first without variables describing proximity to infrastructure, and then integrating them in order to measure the gain in explanatory power. The results suggest that the role of infrastructure in employment growth rate is limited and varies according to economic sectors and network types.