Les contraintes temporelles dans le processus d'élaboration des PDU le cas de Marseille

The legal procedure (laure) for developing an urban travel plan (utp) and the procedure laid down in the certu guide place powerful temporal constraints on the development of a utp. This paper uses the example of Marseille to examine the rules for developing a utp and pays particular attention to the manner in which these temporal constraints may cause the actual development of a utp to diverge from the approach recommended by the certu. The utp development process is examined in detail by applying three types of data collection and analysis: an analysis of documents, attendance of utp and workshops as observers, interviews with players involved in urban planning and the utp. In order to meet temporal constraints the planning team must modify the stages of the process, but it must also adapt to the strategies of elected representatives which are defined outside of the utp procedure (the search for funding, development of transport and urban planning policies and objectives, etc.) as well as the resulting projects (those in the process of being prepared or those which are prepared before the utp). The utp can thus become an urban travel plan which essentially aims to achieve between projects which are already running.     

Indicateurs de comparaison de scenarios prospectifs peut-on elargir le debat sur 1' avenir de la mobilite urbaine?

La construction de scenarios prospectifs de la mobilité urbaine vise généralement a faire émerger un débat sur les évolutions tendancielles, sur les inflexions qu'il conviendrait d'y apporter et sur les strategies a promouvoir. En tenant compte du cadre législatif dans lequel s'inscrivent les procedures de planification des transports a l'échelle locale, nous avons examine dans quelle mesure les indicateurs statistiques de comparaison des scenarios pouvaient s'adapter a la prise en compte des enjeux du développement durable et faciliter l'émergence d'un débat contradictoire autour de ces enjeux. Cet article expose les options méthodologiques générales retenues et fait un certain nombre de propositions concemant le contenu et la mise en forme des indicateurs a construire, en fonction des sujets abordés et des finalites de la démarche prospective.Urban travel prospective scenarios are generally constructed in order to stimulate debate on trends, on how these could be changed for the better, and on the strategies that should be promoted. While referring to the legal framework which applies to transport planning procedures at local level, this paper examines the extent to which the statistical indicators used to compare scenarios can be adapted in order to take account of the issues associated with sustainable development and facilitate the inauguration of an open debate around them. It sets out the general methodological choices that are made and makes a number of proposals about the form and content of the indicators that should be constructed, with reference to the topics covered and the aims of the prospective approach.     

La surestimation de la distance intervéhiculaire dans le brouillard

The difficulties of driving in fog are usually perceived in terms of lower sight distances and reduced ability to anticipate. However, the fall in the quality of visual information can also lead to errors in judgement by affecting the way drivers perceive their environment and their movement within it. We have conducted a series of experiments in a fog chamber and on a driving simulator, with the main aim of investigating the influence of fog on vehicle headway perception. Our results have revealed that distances are seriously overestimated in fog, and that this is likely to contribute to lower headways under such conditions, In fog an overestimation of headway between 20 and 55% was observed when vehicles were visible only as a result of their rear lights, which is the case in night-time or thick daytime fog. Under these conditions, the characteristics of vehicle lights become extremely important. Overestimation of distance becomes greater when vehicles have only one rear light instead of two, and when their two reac lights are close together. Perception of vehicle distance is therefore improved by two rear lights, placed as far apart as possible to indicate the dimensions of the vehicle. No significant overestimation of headways was found during thin or moderate daytime fog, when the vehicle outline remained visible. The results have shown the importance of the familiar size of vehicles as an indicator of distance in the situations we have investigated. They confirm the hypothesis that basic mechanisms of space perception are modified in fog.     

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).     

L'entrée de la Cerdagne française dans l'espace économique barcelonais rôle de l'axe routier du Llobregat

Cerdanva is a mountainous trans-frontier region in the Pyrenees. Completion of the Barcelona-Bourg Madame section of the Barcelona-Toulouse motorway in 1995 brought Cerdanya to within a two-hour drive of Barcelona. This coincided with rising living standards in Catalonia and the creation of new affluent classes. The new road, which is known as the llobregat motorway, brought many more visitors to Spanish Cerdanya. The same occurred two years later from 1989–1990 in French Cerdanya. This increased cross-border traffic can be linked to increasing prosperity in French Cerdanya as witnessed by a rise in average taxable household income. At the same time a large number of properties. changed hands, most of them bought by people from Barcelona, and major property developers from Catalonia arrived in French Gerdanya. Leisure tourism seems to be bringing French Gerdanya into Barcelona's area of influence, which means that the economic and administrative borders are becoming dissociated.     

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.     

Simulation des temps de parcours du transport ferroviaire régional du bassin de vie stéphanois dans le cadre du projet Bahn.Ville

The French-German research project Bahn.Ville, dealing with Rail oriented development and intermodality in German and French urban regions, has consisted in identifying the principles and factors of success of an urban development oriented towards rail, and in testing them in the agglomeration of Saint-Étienne. One of the research-actions focussed on identifying and anticipating the potential impacts in terms of urban development of a new transport system, of the tram-train type, on an existing railway line. The effect of the insertion of new stops on the global journey time is one of the criterion of the evaluation of new stops. A simulation method of the journey times is presented in this paper. The interest and the limits of this approach, regarding the rolling stock choice and the insertion of new stops, are emphasized.     

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.     

下一代de保险杠

汽车保险杠作为一套极其复杂的系统正越来越成为研究的焦点一一它在降低成本和减轻重量这两个方面似乎具有无限的潜力。尤值一提的是,美国的塑料制造商正在开发至少四种下一代的保险杠,它们能使车身结构更紧凑、能使多种零件集中     

香港市民de行

香 港市民行的方式有轮渡、有轨 电车、大巴、中巴、轿车(包括出租车)、地铁、步行街,限于篇幅,只介绍有特点行的方式,其余从略。 香港有轨电车比内地任一处的电车都老式,他们化腐朽为神奇,如今双层有轨电车成为占地最少、利用率最高、票价最低、污染最少的公交工具,还兼作游览观光工具。 港岛的德辅路中段是条很重要的马路,有十几条大巴路线通过。政府规定:从7:00～19:00,这条马路禁止轿车、出租汽车进入,以保证     

生日de 纪念

金秋时节,秋风送爽.闲来无事去了老厂一趟,看望几个早已退休的老同事.     

张福强de改装车

纵使在一些大中城市出现了世界顶尖的代表性车型,原来在人们印象中“低技术”的那些经典摩托车渐渐被认同,但是真正代表中国摩托车车迷的当属那些倾其家底买来一台国产的、一般是两冲程的、100ml上下的摩托车去长途跋涉的那些人。他们在旅途中遇到的困难常常令人难以想象。原因之一是,     

令人费解de离合器

某单位一辆斯太尔91系列载货汽车,离合器出现打滑故障.经维修人员检查,发现摩擦片磨损严重,表面烧蚀硬化,导致离合器打滑.于是从仓库中领出一片同型号的新离合器从动盘,更换原有的旧件.但是修理完毕试车时,却出现了离合器分离不彻底,挂档困难,踏板踏不到底的故障.     

Gibraltar: le projet de lien fixe entre intégration euroméditerranéenne et développement régional

This paper presents a socioeconomic examination of the project for a fixed link in the Strait of Gibralter. This project for a major link between Europe and the Maghreb which would take the form of a rail tunnel can be examined at two different spatial scales, that of the major trade networks which link Europe and the Maghreb and that of the areas which are located near the future points of access to the tunnel. If we pass over the problems which may be posed by the financing of this project (which studies have shown to be profitable), the geopolitical context of changing relations within Europe and the Mediterranean should be favourable to its construction. Its strategic (and at the same time symbolic) character is defined by its role as a link between the trans-European networks and the southwestern shore of the Mediterranean basin. This physical connection may nevertheless generate undesired or even counterproductive effects in the directly exposed economies on the southern side. Additional strategies could be considered for which the existence of a tunnel would constitute an opportunity. These are referred to as accompanying measures in French regional planning policy.