Détection de chutes de personnes sur les voies et d'intrusions en tunnels dans les transports publics

In the framework of the European cromatica project, which aims to improve public transport safety, we have developed a computer vision application for detecting persons or objects falling onto the tracks or non-authorized persons intruding into tunnels when trains are running. The study includes the creation of a demonstrator. Currently, most metro systems have no video coverage of sensitive zones such as platform/track interfaces, tracks and tunnel entrances. When such coverage has been installed, use of the images merely involves the operator observing sensitive zones on an occasional basis, in particular when informed about an incident by other means. In contrast, we propose a completely automatic system based on permanent video monitoring of platform/track interfaces, tracks and tunnel entrances. A first algorithm, built into a processing board in a pc, processes video images in order to detect movement in prohibited zones. Then other algorithms localize this movement and measure the size of the object. The decision whether or not to alert the operator is then taken. The first results from the demonstrator, which has been installed at the Paris Metro station Havre-Caumartin, are very encouraging.     

L'utilisabilité d'internet comme source d'information pour les voyageurs handicapés

This paper considers some of the difficulties that disabled persons, may experience when using the Internet to obtain transport information. The selected examples are from the European TELSCAN project, which is part of the Fourth Research and Development Framework Programme, and in particular relate to persons with hearing or visual impairment. An ergonomic analysis of the use of Internet servers by persons with hearing or visual disabilities has demonstrated the importance of the semantic structure of the presented information and the nature of information search procedures. However, the observations have shown that the Internet is nevertheless a very useful source of information for disabled travellers.     

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.     

Détection de stationnarités anormales dans les couloirs du métro

One of the factors which discourages use of public transport is the feeling of insecurity. In order to overcome this, the operators of metro networks are attempting to find techniques to detect more incidents or anomalies rapidly. It is within this framework, as part of the European cromatica project, that research has been undertaken at inrets by the video team in the Traffic Analysis and Control Department (dart). This paper will concentrate on the detection of abnormal stationarities in metro corridors. Operators wish to identify events of this type as a prolonged stationarity may denote the presence of a drug pusher, an illicit vendor, a thief watching a potential victim, a homeless person, a person suffering from illness, a person who has had a fall, or an abandoned object. The paper firstly gives an account of the developed system and its context and then describes the image processing techniques which have been used. The results obtained with real complex situations are then presented.     

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.     

Comment les péages urbains peuvent-ils satisfaire une politique d’agglomération ?

This paper evaluates the extent to which urban road pricing schemes are able to satisfy the objectives of urban policy with regard to three frequently incompatible constraints: funding, the environment and social equity. We have devised a technical tolling system which reconciles these objectives and applied it to the case of the Lyon conurbation. We reach a number of conclusions concerning the effectiveness of different toll scenarios in terms of vehicle × kilometres travelled, travel durations, atmospheric emissions and funding. In general, achieving a simultaneous improvement in the above criteria requires at least the introduction of zonal tolls which reduce private car use by those residing in the conurbation and provide funding for alternative forms of transport.     

Âge des conducteurs de voiture et accidents de la route: Quel risque pour les seniors ?

Increasing life expectancy and the fact that the baby boomer generation is reaching retirement age are increasing the size of the elderly population. As road users, seniors have quite specific travel behaviours, and this has an impact on accidents. This paper adopts a quantitative approach with a view to showing the specific characteristics of elderly drivers as regards travel, accidents and road risk. Towards this end it surveys a number of previous studies and takes advantage of recent data to update some of the findings of these contain. Some road risk indicators are described, and attention is paid to the methodological bias inherent in the methods employed. Our analysis shows that the presence of seniors on the roads is growing as the proportion, particularly of the women, in this group who are accustomed to driving increases. They nevertheless cover fewer kilometres than other drivers and develop compensatory strategies, for example not driving when conditions are difficult or driving more slowly than other drivers. When they have accidents they tend to be more severe because of their greater vulnerability. They have higher crash involvement at intersections as a result of detection and estimation difficulties in the driving task. The excess crash risk per kilometre driven for seniors that was observed a few years ago is tending to fall, or even disappear, if the low mileage bias is taken into account.     

Quelles interactions entre les marchés de la mobilité à courte et à longue distance ?

This paper proposes a comprehensive quantitative approach to travel analysis that considers personal travel practices with regard to three travel market segments: local weekday travel, local weekend travel and long-distance travel. The first section consists of an evaluation of the overall size of these segments and demonstrates the increasing importance of long-distance travel. Each market segment and then travel as a whole are then analyzed according to individuals’ position in the life cycle, residential location and income level. Last, the roles of location and income in the creation of travel demand in the different segments are then investigated for individuals in the middle part of the life cycle. In particular, it is demonstrated that weekend and weekday travel do not compensate for one another, but there are significant interactions between both local and long-distance travel, and, in particular, residential location.     

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.     

L'étalement de spectre par séquence directe Une solution pour les communications radio en milieu perturbé

The need for robots to communicate in hostile environments (such as nuclear power plants) led the cea-letl to appoly its knowledge in the field of spread spectrum. By using an innovative reception structure and a diversity system the Direct Sequence Spread Spectrum (dsss) technique is able to take advantage of the multipath phenomena where conventional radio using narrow band modulations fail. The first receivers developed in the laboratory were based on surface acoustic waves filters. Progress in microelectronics meant that these analog components could be replaced by dedicated programmable digital circuits which performed all the baseband processing. The resulting flexibility has allowed us to develop high bit rate systems (up to 10 Mbits/s). Particularly well-suited for multipath environments, this technique has potential applications in a wide variety of areas, for example indoor video monitoring track-to-train communications in metro systems and communications between the head and the rear of heavy-long trains.     

Certification des automatismes numériques dans les transports guidés : projets européens CASCADE et ACRuDA

This paper presents current work which deals with the certification of automatic train protection systems according to European standards and has three main sections. The first deals with the current situation as regards third party conformity certification on the basis of a reference document. The role of notified assessors and the requirements of European standards such as Cenelec 50126, 128 and 129 are discussed and the essential elements of the European high speed train interoperability directive are given. The second section summarizes the results of the Cascade project (Certification and Assessment of Safety-Critical Application Development) which is part of the Esprit III programme. This project deals with the harmonization of the various evaluation and certification approaches for safety critical software in railway applications. Its aim is to formulate a shared evaluation method to enable safety critical software to be certified by any notified assessor in a State in the European Union with the same criteria and rules, and in accordance with applicable European standards. The third section of the paper presents the Acruda project (Assessment and Certification Rules for Digital Architectures) which supplements the work on software carried out in Cascade. This project concerns the certification of hardware architectures and makes it possible to implement certification rules for the computers used to ensure the safety of train control systems.     

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.     

Mobilité et accès à la voiture chez les personnes âgées: Évolutions actuelles et enjeux

In France, and in most other industrialised countries, demographic ageing means that in the next decades there will be a rise among the elderly in vehicle ownership and driving for daily trips, long distance travel and leisure trips. This paper demonstrates the existence of these trends by drawing on a variety of statistical sources — National Transport and Communication Surveys, Urban Household Travel Surveys (Lyon) and surveys on French holiday practices. We nevertheless demonstrate that this structural change exhibits a high degree of differentiation with regard to gender, household income, place of residence and state of health. This change, which increases car use, is expected to continue during the next few years, especially among elderly women. Long term changes in lifestyles encourage the view that in the future people will cease to drive at a more advanced age. The increase in car use has important long-term implications in two areas. On the one hand it will affect road safety, on the other hand it raises the issues of the sustainability of mobility and the obligation to meet the needs of persons who are no longer able to drive.     

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.     

Impact de la tarification,des fréquences et des temps de transfort sur les flux ferroviares dans le Bassin parisien

We have modelled trips on the Paris basin on the basis of the SNCF long-distance surveys. This modelling allows us to test the impact of pricing, journey times and train frequencies on rail travel demand. Three models have been constructed — a generation model (which computes trip production, that is to say the distribution of trips on the basis of the zones in which rail users reside), a geographical distribution model which is used to estimate the distribution of trip production on the basis of origin and destination zone, and lastly a model choice model which computes the proportion of commuting flows which takes place by rail. In this study the generation model has been partially supplied by the surveys. The distribution model takes thetrip production data output from the generation model in order to evaluate the total of rail flow on each O-D pair. This data is then used to calibrate the modal choice model.