Information routière par RDS-TMC: enjeux de l'interopérabilité

There was a range of systems and technologies for broadcasting road traffic information in different countries in the European Union and interoperability between the various systems must be achieved to enable road users to use the same on board equipment in different countries so that they can receive the same information service in their own language throughout a journey, whether local, regional, national or international. This paper mainly deals with the broadcasting of road, traffic information via RDS-TME and begins by describing some technical features of this medium. If the proceeds to examine issues of interoperability between RDS, TME based road traffic information systems.     

Modèles linéaires généralisés appliqués à l'étude des nombres d'accidents sur des sites routiers: Le modèle de Poisson et ses extensions

Models that link accident frequencies at road sites with traffic volumes and road characteristics provide reference values which are of value when carrying out diagnostic studies and deciding on preventive measures. Such models can be developed using generalized linear modelling techniques, which are able to take account of the Poisson properties of accident frequencies at road sites. The Poisson models obtained for road sites are frequently everdispersed, so extended forms of the Poisson model (quasi-Poisson, negative binomial a high percentage of the studied sites, in which case zero-inflated models also have to be considered. This paper presents an overview of these methods which are illustrated by modelling the relationship between accident frequency site characteristics and traffic volume on a large sample of bends.     

Utilisation de modeles linéaires généralisés pour tester l'effet sur la sécurité d'une modification d'infrastructure comparaison des glissières en métal aux barrières en béton en terre-plein central d'autoroute

Generalized linear models provide a unifying framework which permits application of most of the interential methods that can be used to evaluate the impact of a road safety, measure. When observations are available before and after the introduction of the measure (i.e., when there is an experimental sample and a control sample which covers the same period which indicates what would have hapened if the measure had not been introduced, the difference between the two samples can be characterized d'using the appropriate interaction term. The models used estimate relative risk or incidence rates and are able to take into account a reasonable number of confounding factors. These methods have been applied in order to compace the severity of impacts with metal guardrails or concreté safety barriers on motorway central reservations. Poisson regression modelling has revealed a tendency for the risk of injury to be higher on road sections where concréte devices have a recently been installed. Multivariate analysis using logistic regression with adjustment with reference to certain factor for example a change in the number of lanes or the occurrence of a second impact shows that concrete barrier significantly increase (by a factor or about 1.9) the risk of injury in the case of a first impact on the central reservation. This estimate could be used in a more general cost benefit analysis.     

Demande de transport de personnes: une théorie unifiée de l'urbain à l'intercontinental Première partie: modalités de réalisation d'un voyage potentiel

This paper proposes a theory which links some of the characteristics of trips made by individuals to the travel price and time provided by transport supply, with reference to the socio-economic context. This model appears to be able to reproduce the phenomena that are observed when there is a change in the supply or context on a given origin-destination link. However, above all, the same model can also reproduce those phenomena (changes in urban development aside), which are different in an urban and an interurban context: greater personal mobility, shorter period away from home, lower value of time among travellers, different modal split for trips, slower increase in the number of trips as a result of the socio-economic context, etc. The first part of the paper shows how each of an individuals potential journeys may be characterized by wishes concerning different aspects of the journey and how the different alternatives for the journey in a given context of transport and accommodation supply can be assessed with reference to the gap between wishes and real characteristics. The second part shows how it is possible to determine the total population of journeys made with reference to both the context and supply. The theory has been illustrated by numerical results obtained for a variety of situations which are representative of urban and interurban areas.     

Quelle place pour la sécurité routière dans les plans de déplacements urbains? Entre intégration et diffusion,le cas du plan de déplacements urbains de Lille métropole

This paper describes the position given to road safety in Urban Travel Plans by analyzing Urban Travel Plan document from eleven cities and undertakes a more in-depth investigation of road safety in the Urban Community of Lille. These plans provide an opportunity to disseminate knowledge about road safety to the other areas of urban management. They also describe the beginning of an integration of road safety in urban planning, even if intersectoral approaches at city level have yet to be developed and even if, in the case of Lille, the division of institutional competence with regard to the management of public space still requires clarification.     

Analyse de la prise en compte de la sécurité routière dans les plans de déplacements urbains

At the time when Urban Travel Plans (utps) are being introduced it is important to see how they take safety into account, certu's analysis of a dozen recent docuements shows the position occupied by road safety in utps, reveals the stated aims of the utps, identifies local actions aimed at improving road safety and highlights current or foresedable problems in the implementation of utps. The analysis shows that the way safety is taken into account varies considerably from one city to another. The desire to introduce measures to improve safety is usually present, but there is uncertainty as to how to tackle the issue. The examples of methods and actions that are given in this paper may provide some ideas which merit further examination for utps in the future. It is already obvious that utps will be responsible for profound changes in urban travel and its safety, and the results obtained over the next five years will doubtless have important consequences for the cities of tomorrow.     

Comparaison entre les informations visuelles données par deux types de systeème de guidage

In recent years, researchers have been working on the design of navigational aids and route guidance systems. Existing systems provide information of different types and present it in a variety of ways. Information is sometimes given as text (either written or orally by speech synthesis). Exclusively visual systems may include symbols, or even better represent landmarks with simplified icons. As yet no systems provide a representation which is analogous to the road scene. In order to assist drivers on their journey we have developed pictural information which contains photographs of landmarks with arrows showing which direction to take (pictural system). From the literature on cognitive psychology and the disciplines that relate to spatial cognition, we already know the representational importance of landmarks for persons who are unfamiliar with a location. We therefore conducted experiments to compare the effects of two types of spatial information, pictural and symbolic (just with arrows), which is communicated to individuals in the real driving situation on an unfamiliar journey. This exploratory study has provided us with some insights into the limits and constraints that apply to the use of photographs as a source of route guidance information for drivers.     

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.     

Besoins en information et problèmes d'utilisation des transports ferroviaires par les personnes déficientes visuelles

This paper describes some of the findings of the biovam project, which deals with the difficulties encountered by the visually impaired when travelling on public transport, for example buses, the underground or trains. The biovam project brings together a team of researchers who are specialized in the accessibility of transport to disabled persons, mobility instructors for the visually impaired and two public transport operators, the ratp (the Paris Region Public Transport Authority) and the sncf (French National Railways). The biovam project performed a survey which identified the difficulties encountered by visually impaired travellers, and then conducted an inventory of the technical devices which could alleviate these problems. This paper pays particular attention to train travel, which differs from other modes in particular as regards frequency of use, journey duration and the nature of the infrastructure and the rolling stock. The presented findings have led to a number of recommendations and the organization of an experimental program which has renewed financial support from predit.     

Réflexions sur l'usage des modèles dans les études de transport et les sciences sociales

The mathematical modelling of human behaviours is extremely common in both theoretical and applied transport studies. This paper begins with an attempt to demonstrate the limits which apply to the reconstruction of a human reality (in this case an origin-destination matrix) by means of a straightforward and commonly used model, the gravity model. These limits stem from the fact that economic, social and political factors and historical aspects are ignored. The reasons for the prevalence of models in transport studies are then discussed as are the consequences of this prevalence: perpetuation of a view of the operation of society which is far from being without political implications, the surrender of the political community to experts, pseudo-scientific justifications for projects for which politicians do not wish to take responsibility.     

Le projet isis: une interface intégrée de sécurité

In order to meet safety, reliability and availability constraints for passenger transport systems, the manufacturers of railway control-command systems must develop specific computer architectures for signalling, switch control and automatic driving applications. Typically, these systems consist of a core (with one or two central processing units) and peripherals via which the computer communicates with external devices. In the case of some applications, for example signal boxes, the architecture contains a very large number of fail-safe True or False outputs. These functionalities are currently performed by conventional technology that uses discrete components or hybrid circuitry.     

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.