Abstract

Cet ouvrage reprend dix contributions issues du colloque " Mobilités et temporalités " organisé aux Facultés universitaires Saint-Louis à Bruxelles en mars 2004. Cette réunion s'inscrivait dans le cadre des travaux du groupe de travail "Mobilités spatiales et fluidités sociales" de l'Association internationale des sociologues de langue française (AISLF).; L'objectif de cet article est d'éclairer comment les moyens de transport à grande vitesse contemporains - on considérera surtout le TGV - répondent aujourd'hui aux structures temporelles de la société. On s'appuiera pour cela sur la distinction de différentes constructions collectives du temps, des temps sociaux."br /"La première partie s'attachera à décrire comment le capitalisme industriel a généré un temps industriel compatible avec la conception du travail qu'il implique. On verra que ce modèle évolue mais conserve une forte pertinence au regard de certains aspects importants des structures socio-économiques contemporaines. Pourtant, cette permanence ne semble pas en mesure de rendre compte de la totalité des évolutions actuelles."br /"La seconde partie illustrera comment les comportements de déplacement à grande vitesse - on se limitera aux déplacements à motif professionnel - révèlent ainsi un certain nombre de ruptures fondamentales avec le modèle du temps industriel."br /"En troisième partie, le modèle du temps fragmenté qui viendrait peu à peu se surimposer au premier, sera alors proposé."br /"Enfin, à travers les figures de la grande vitesse comme opportunité et de la grande vitesse comme nécessité, la dernière partie présentera une lecture duale, adaptée à la double structure temporelle qui prévaudrait aujourd'hui, des modalités de gestion de la distance à travers les moyens de transport rapides. Document type: Part of book or chapter of book

Abstract

This paper assesses the impact of labor mobility on racial discrimination. We present an equilibrium search model that reveals an inverted U-shaped relationship between labor mobility and race-based wage differentials. We explore this relationship empirically with an exogenous mobility shock on the European soccer labor market. The Bosman ruling by the European Court of Justice in 1995 lifted restrictions on soccer player mobility. Using a panel of all clubs in the English first division from 1981 to 2008, we compare the pre- and post-Bosman ruling market to identify the causal effect of intensified mobility on race-based wage differentials. Consistent with a taste-based explanation, we find evidence that increasing labor market mobility decreases racial discrimination. Document type: Report

Abstract

Mobility and transport evolve with time and the passing generations. Interactions are numerous between daily mobility and household migration (here defined as house moving implying a municipality change). The evolution of the transport system has deeply modified the barrier of distance and has largely opened the choices in terms of residence place. The continuing urban sprawl phenomenon resulting from these modifications has itself resulted in a strengthening of the property and housing market in certain territories, pushing people (young couples in particular) towards a residential localization which is further and further away from the traditional, urban activity centres. The tensions between daily and residential mobility have therefore increased, notwithstanding the recent rise in energy costs. This in turn generates unsustainable effects on society and environment. But these new residential choices have in parallel induced new mobility behaviours, based on an extensive (and probably excessive) use of the private car in daily trips (home-work/school, shopping, leisure ...). Social life itself (visits to friend and family) has become more spatially dispersed. One already knows that the propensity to change residence is determined by a number of individual or household characteristics such as age, citizenship or income, but the effects of long-term trends as population ageing, the evolution of the household/family structure on both residential choices and mobility behaviours remain so far largely unanticipated. This research project aimed at analyzing interactions between demographics and the evolution of mobilities at different time-scales. In particular, localization choice for household, daily accessibility and internal migrations ap pear to have strong relations. Document type: Report

Abstract

This work is reproduced here with the kind permission of the publisher, ISEAS - Yusof Ishak Institute, http://bookshop.iseas.edu.sg; International audience; There is no point in attempting to formulate a synthesis of the présentations contained in the présent publication given the diversity of the subjects. Our ambition here is, firstly, to recapitulate on some of the issues dealt with by the PRUD (Urban Research Programme for Development) projects, as well as to review some of the main characteristics of urban mutations in Vietnam during the current transition period as outlined in the work carried out by the research teams. Secondly, we will suggest orientations for future research: based on existing knowledge accumulated through research projects carried out within the scope of the PRUD, we will either further investigate current thèmes and issues or explore new ones.

Abstract

The main goal of this dissertation is to answer one of the critical questions about dynamic ride-sharing services: Can dynamic ride-sharing reduce congestion? In this thesis, we propose a simulation-based optimization framework for dynamic ridesharing. Then using this framework, we assess the dynamic ride-sharing impact on two different network scales to find the answer to this question. When assessing the dynamic ride-sharing problem, two important points should be considered. First, how the ridesharing system serves the network demand and second, how the ride-sharing system is impacted by the network and in particular by congestion. Then we can assess the impact of such a service on the network. Most of the existing approaches focus on the first point, i.e., designing the demand matching while using basic assumptions for the second point, mainly constant travel times. The proposed method in this thesis can outperform the existing methods in the literature. The optimization algorithm can provide high-quality solutions in a short time. Our solution approach is designed to be exact for small samples. Then, to be able to handle the large-scale problems, it is extended with several heuristics that keep the general design for the solution method but significantly reduce its computation time. In the simulation component, a "Plant Model" is applied based on the "Trip-based Macroscopic Fundamental Diagram (MFD)" to represent the traffic dynamics reality and a "Prediction Model" is applied based on the mean-speed to be used during the assignment process. We perform an extensive simulation study (based on real-world traffic patterns) to assess the influence of dynamic ride-sharing systems on traffic congestion. In the medium-scale (Lyon 6 + Villeurbanne), the results showed that ride-sharing could not significantly improve the traffic situation. High levels of market-share add additional travel distance and travel time to the trips and lead to more traffic in the network. In large cities, the results are entirely different from those in small and medium-sized cities. In large-scale (Lyon city in France) simulations, the proposed dynamic ride-sharing system can significantly improve traffic conditions, especially during peak hours. Increasing the market-share and the number of sharing can enhance this improvement. Therefore, the proposed dynamic ride-sharing system is a viable option, alleviating stress on existing public transport, to reduce the network traffic in populated and large-scale cities.; The main goal of this dissertation is to answer one of the critical questions about dynamic ride-sharing services: Can dynamic ride-sharing reduce congestion? In this thesis, we propose a simulation-based optimization framework for dynamic ridesharing. Then using this framework, we assess the dynamic ride-sharing impact on two different network scales to find the answer to this question. When assessing the dynamic ride-sharing problem, two important points should be considered. First, how the ridesharing system serves the network demand and second, how the ride-sharing system is impacted by the network and in particular by congestion. Then we can assess the impact of such a service on the network. Most of the existing approaches focus on the first point, i.e., designing the demand matching while using basic assumptions for the second point, mainly constant travel times. The proposed method in this thesis can outperform the existing methods in the literature. The optimization algorithm can provide high-quality solutions in a short time. Our solution approach is designed to be exact for small samples. Then, to be able to handle the large-scale problems, it is extended with several heuristics that keep the general design for the solution method but significantly reduce its computation time. In the simulation component, a "Plant Model" is applied based on the "Trip-based Macroscopic Fundamental Diagram (MFD)" to represent the traffic dynamics reality and a "Prediction Model" is applied based on the mean-speed to be used during the assignment process. We perform an extensive simulation study (based on real-world traffic patterns) to assess the influence of dynamic ride-sharing systems on traffic congestion. In the medium-scale (Lyon 6 + Villeurbanne), the results showed that ride-sharing could not significantly improve the traffic situation. High levels of market-share add additional travel distance and travel time to the trips and lead to more traffic in the network. In large cities, the results are entirely different from those in small and medium-sized cities. In large-scale (Lyon city in France) simulations, the proposed dynamic ride-sharing system can significantly improve traffic conditions, especially during peak hours. Increasing the market-share and the number of sharing can enhance this improvement. Therefore, the proposed dynamic ride-sharing system is a viable option, alleviating stress on existing public transport, to reduce the network traffic in populated and large-scale cities.

Abstract

Travel practices are changing: bicycle and motorized two-wheeler (MTW) use are rising in some of France's large cities. These are cheaper modes of transport and therefore attractive at a time of economic crisis, but they also allow their users to avoid traffic congestion. At the same time, active transport modes such as walking and cycling are encouraged because they are beneficial to health and reduce pollution. It is therefore important to find out more about the road crash risks of the different modes of transport. To do this, we need to take account of the number of individuals who use each, and, even better, their travel levels. We estimated the exposure-based fatality rates for road traffic crashes in France, on the basis of the ratio between the number of fatalities and exposure to road accident risk. Fatality data were obtained from the French national police database of road traffic casualties in the period 2007-2008. Exposure data was estimated from the latest national household travel survey (ENTD) which was conducted from April 2007 to April 2008. Three quantities of travel were computed for each mode of transport: (1) the number of trips, 2) the distance travelled and (3) the time spent travelling. Annual fatality rates were assessed by road user type, age and sex. The overall annual fatality rates were 6.3 per 100 million trips, 5.8 per billion kilometers travelled and 0.20 per million hours spent travelling. The fatality rates differed according to road user type, age and sex. The risk of being killed was 20 to 32 times higher for motorized two-wheeler users than for car occupants. For cyclists, the risk of being killed, both on the basis of time spent travelling and the number of trips was about 1.5 times higher than for car occupants. Risk for pedestrians compared to car occupants was similar according to time spent travelling, lower according to the number of trips and higher according to the distance travelled. People from the 17-20 and 21-29 age groups and those aged 70 and over had the highest rates. Males had higher rates than females, by a factor of between 2 and 3. When exposure is taken into account, the risks for motorized two-wheeler users are extremely high compared to other types of road user. This disparity can be explained by the combination of speed and a lack of protection (except for helmets). The differential is so great that prevention measures could probably not eliminate it. The question that arises is as follows: with regard to public health, should not the use of MTW, or at least of motorcycles, be deterred? The difference between the fatality risk of cyclists and of car occupants is much smaller (1.5 times higher); besides, there is much room for improvements in cyclist safety, for instance by increasing the use of helmets and conspicuity equipment. Traffic calming could also benefit cyclists, pedestrians and perhaps moped users. Language: en Document type: Conference object

Abstract

8th International Congress on Transportation Research: Transportation by 2030: Trends and perspectives, THESSALONIKI, GRECE, 27-/09/2017 - 29/09/2017; This paper focuses on the description of societal trends related to mobility and on the way that these trends can be perceived from the society, when implemented. This action represents the starting point of the European project Mobility4EU that focuses on creating an action plan for the coherent implementation of innovative transport and mobility solutions in Europe. In Mobility4EU we have defined a set of possible societal aspects that might lead to societal resistance to the implementation of the future transport megatrends that have been defined. This paper aims to highlight the possibility of societal resistance to a wider implementation of innovative transport solutions, related to foreseen megatrends for the 2030. In consequence the list has not the ambition to be comprehensive, but rather provide a first overview of the societal reaction to widespread diffusion of foreseen solutions. Document type: Conference object

Abstract

hEART 2019, 8th Symposium of the European Association for Research in Transportation, Budapest, HONGRIE, 04-/09/2019 - 06/09/2019; In recent years, intelligent transportation systems made it possible for operators to adapt in real-time the transportation supply to travel demand via new mobility services. Among these services, ride-sharing is becoming popular. The dynamic ride-sharing problem involves two sub-problems: (1) How to serve the upcoming trips (Optimal fleet management) and (2) How to accurately predict the travel times to determine vehicles availability and pick up/drop off times. In this paper, we express the optimal fleet management problem as a constrained multi objective integer linear programming. Our aim is to find the global optimal solution for the ride-sharing problem without uncertainty in demand to have a vision of these services performance in optimal situation. Then we compare the results and experiments with the exact optimal condition. We have designed an algorithm to find the exact solution for matching problem based on the branch and bound algorithm. To solve the second sub-problem, we define two different models to assess the impact of traffic conditions on the dynamic ride-sharing system performance for large-scale problems.