Laboratoire Aménagement Économie Transports

Panel data econometrics is obviously one of the main fields in the profession, but most of the models used are difficult to estimate with <b>R</b>. <b>plm</b> is a package for <b>R</b> which intends to make the estimation of linear panel models straightforward. <b>plm</b> provides functions to estimate a wide variety of models and to make (robust) inference.

International audience

In industrialized countries, the number of studies and surveys in the field of urban goods movement (UGM) has increased considerably over recent years. This paper compares the objectives, methods and results in this sector and focuses on nine industrialized countries of Europe, America and Asia. This non‐extensive review shows that in spite of different framework methods and models, similar trends emerge at the economic and environmental levels. It is necessary to take into account urban logistics in the broadest meaning of the term. Cooperative action seems to bear fruit providing that information and dialogue take place in the long‐term with all the operators involved. The development of intelligent transport systems (ITS) and better management of urban facilities may improve these attempts. We present our viewpoint in order to shed light on research oriented towards the sustainable management of urban logistics.

This paper investigates the impact of ownership structure and contractual choices on technical efficiency in the French urban public transport sector. The central proposition, which relies on classical contract theory arguments, is that ownership regime and contractual practices are key determinants of performance. To test this proposition, the authors use an original panel data set covering 135 different French urban transport networks over the period 1995–2002 and apply a stochastic frontier methodology. The econometric results corroborate their proposition that the technical efficiency of urban public transport operators depends on the ownership regime and on the type of contract governing their transactions.

This paper aims to present a modeling of bike sharing demand at station level in the city of Lyon. Robust linear regression models were used in order to predict the flows of each station. The data used in this project consists of over 6 million bike sharing trips recorded in 2011. The built environment variables used in the model are determined in a buffer zone of 300 meters around each bike sharing station. In order to estimate the bike sharing flow, we use the method of linear regression during the peak periods of a weekday. The results show that bike sharing is principally used for commuting purposes by long term subscribers while short term subscriber's trips purposes are more varied. The combination between bike sharing and train seems to be an important inter-modality. An interesting finding is that student is an important user of bike sharing. We found that there were different types of bikesharing usage which are influenced by socio-economic factors depending on the period within the day and type of subscribers. The present findings could be useful for others cities which want to adopt a bikesharing system and also for a better planning and operation of existing systems. Further, the solutions to encourage the use of bikesharing will be various depending on type of subscribers. The approach in this paper can be useful for estimating car-sharing demand.

Linking microscopic and macroscopic behavior is at the heart of many natural and social sciences. This apparent similarity conceals essential differences across disciplines: Although physical particles are assumed to optimize the global energy, economic agents maximize their own utility. Here, we solve exactly a Schelling-like segregation model, which interpolates continuously between cooperative and individual dynamics. We show that increasing the degree of cooperativity induces a qualitative transition from a segregated phase of low utility toward a mixed phase of high utility. By introducing a simple function that links the individual and global levels, we pave the way to a rigorous approach of a wide class of systems, where dynamics are governed by individual strategies.

International audience

This paper describes a framework for analysing the acceptability of pricing changes in the transport sector. This framework is based on Rawls' theory of justice and makes reference to economic efficiency (efficiently managing demand), spatial equity (guaranteed access), horizontal equity (the user pays principle) and vertical equity (the welfare of the most underprivileged). This analytical framework is then applied to an urban toll motorway that was opened in Lyon in 1997, in association with capacity restrictions on the parallel roads. The different types of efficiency and equity that were brought into play by this scheme are analysed and illustrated by quantitative results. We show how their negative aspects combined. This study shows that this framework can be applied to practical understanding of justice issues, and particularly for assessing the feasibility of road pricing schemes in urban areas.

Objectives We sought to determine whether interventions that target work organization or the psychosocial work environment are effective in preventing or reducing work-related musculoskeletal disorders (WMSD) compared to usual work. Methods We systematically reviewed the 2000-2015 English- and French-language scientific literature, including studies evaluating the effectiveness of an organizational or psychosocial work intervention on incidence, prevalence or intensity of work-related musculoskeletal pain or disorders in the neck, shoulders, upper limbs and/or back or of work absence due to such problems, among non-sick-listed workers. We excluded rehabilitation and individual-level behavioral interventions and studies with >50% attrition. We analyzed medium- and high-quality studies and synthesized the evidence using the Grading of Recommendations Assessment, Development & Evaluation (GRADE) approach. An analysis of key workplace intervention elements supplemented the interpretation of results. Results We identified 884 articles; 28 met selection criteria, yielding 2 high-quality, 10 medium-quality and 16 low-quality studies. There was moderate evidence that supplementary breaks, compared to conventional break schedules, are effective in reducing symptom intensity in various body regions. Evidence was low-to-very-low quality for other interventions, primarily due to risk of bias related to study design, high attrition rates, co-interventions, and insensitive indicators. Most interventions lacked key intervention elements, such as work activity analysis and ergonomist guidance during implementation, but the relation of these elements to intervention effectiveness or ineffectiveness remains to be demonstrated. Conclusions Targeting work-rest cycles may reduce WMSD. Better quality studies are needed to allow definitive conclusions to be drawn on the effectiveness of other work organizational or psychosocial interventions to prevent or reduce WMSD.

In the frame of the ARTEMIS European research project, a compilation and synthesis of previous works has been considered to derive a set of reference real-world driving cycles. These driving cycles should be used in the frame of the multiples campaigns of pollutant emission measurements, ensuring then the compatibility and integration of all the resulting emission data in the European systems of emission inventory. The available data regarding driving conditions and the various methodological approaches have been examined, discussed, compared and improved, to ensure and validate the representativity of the database and driving cycles. Specific steps have also been implemented. Three real-world driving cycles (urban, rural road and motorway) have been built-up to be representative of the actual conditions of vehicle usage and driving and to reproduce the diversity of the observed driving conditions. A structure in sub-cycles should enable a disaggregation of the emissions according to more specific driving conditions (congested and free-flow urban, etc.). Starting conditions and gearbox use are also taken into account. Such driving cycles present a real advantage as they are derived from a large database, using a methodology that was widely discussed and approved. They are probably the results of the most advanced works in that area. This report includes a second part dedicated to the construction of 2 sets of specific driving cycles, using the same principles and data, but build-up as a function of the technical characteristics of the vehicles, i.e. for low- and high-motorized vehicles.

Multi-echelon distribution systems are quite common in supply-chain and logistic systems. They are used by public administrations in their transportation and traffic planning strategies as well as by companies to model their distribution systems. Unfortunately, the literature on com- binatorial optimization methods for multi-echelon distribution systems is very poor. The aim of this paper is twofold. Firstly, it introduces the family of Multi-Echelon Vehicle Routing Problems. Second, the Two-Echelon Capacitated Vehicle Routing Problem, is presented. The Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP) is an extension of the classical VRP where the delivery passes through intermediate depots (called satellites). As in the classical VRP, the goal is to deliver goods to customers with known demands, minimizing the total delivery cost while considering vehicle and satellites capacity constraints. A mathematical model for 2E-CVRP is presented and some valid in- equalities given, which are able to significantly improve the results on benchmark tests up to 50 customers and 5 satellites. Computational re- sults under different realistic scenarios are presented.

Mobile phone operators produce enormous amounts of data. In this paper we present applications performed with a dataset (communication events + handover and Location Area Up-date) collected by the operator Orange from 31 March to 11 April 2009 for the whole Paris Region. Trips are deduced from the spatio-temporal trajectory of devices through a hypothesis of stationarity within a Location Area in order to define activities. Trips are then aggregated in an origin-destination matrix which is compared with traditional data (census data and household travel survey).

The car is still the most common mode of transport in Western countries, particularly so across the European Union, as it accounts for about two-thirds of daily commuting. So far, measures aiming to reduce automobile traffic and incentives for the modal shift to public transport and non-polluting methods of travel (walking, cycling, etc.) have had little effect. Moreover, the car lies at the core of a very complex system that has proven to be difficult to unlock. In light of these challenges, using new types of engine power may appear to be a solution. Electric vehicles have the potential to improve the efficiency, affordability, and sustainability of the transport system. However, there remains much uncertainty as to how such a transition from one type of engine to another may unfold, and where it could take place within the European context. In June 2017, the H2020 project SHAPE-ENERGY launched an online debate on the Debating Europe platform with the question: “Should all cars be electric by 2025?”. The aim of the debate was to elicit citizens views on whether the goal could be reached, how and with which consequences. The diversity of the vantage points that have appeared in the subsequent discussion generated by the strands of debate allows us to bring into discussion the viewpoints and arguments that are not often addressed in the literature on the adoption of electric cars in a comprehensive way. The article sheds light on those debates across Europe, in order to bring new insights to European policymakers that are seeking to promote the market for electric vehicles. It also broadens the scope and offers important contributions to scholarly debates on the diffusion and adoption of such vehicles.

In hybrid vehicles, lithium-ion cells constituting a battery pack are frequently used to provide and recover high power to assist the vehicle's internal combustion engine (ICE) powertrain. This usage is more present in mild hybrid applications where the battery does not have long discharge time. Under such conditions, the pack's series resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> proved to be an important parameter to monitor since its evolution depends on the cell's characteristics (manufacturing tolerance, temperature, etc.). This resistance, which is monitored by the battery management system (BMS), reflecting the available power level in the cell can be used as an indicator to enhance the security of the battery pack. Its evolution can be used to quantify its aging (state of health: SoH). This paper presents an online approach to identify the cell's series resistance based on a direct estimation of R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> . This parameter can be usually identified through the voltage drop occurring across the cell caused by a high current variation profile (mild hybrid conditions). These estimated values are then filtered with an “exponential moving average” method to limit the measurement noise effect. This approach provides good results for mild hybrid conditions, while minimizing the computing power required.

Understanding temporal rhythms in travel and activity patterns has been recognized as an important issue for the effective management of urban congestion. Research issues related to this topic concern the degree to which travel behaviour varies from one day to another, the differences between weekday and weekend travel, and the determinants of variability. Thanks to a seven-day travel diary collected for 707 individuals in the city of Ghent (Belgium) in 2008, this study goes further by studying this variability according to various time periods within the week and by analysing interpersonal and intrapersonal variations according to the varying attributes of activity-travel patterns. Different variance indicators and the sequential alignment method are applied for the measurement of variability of travel-activity behaviour. Moreover, the influence of individual characteristics on these variations is examined. The overall picture of a large intrinsic variability in travel behaviour (i.e. trip or home-based tour generation) is confirmed. There is more difference in the number of trips per day for a given individual depending on the various days of week than there is between individuals per se, not including the weekend period, and this aspect is reinforced when considering home-based tours. Unlike the case of trip generation, there is greater difference between persons in their daily time allocation to various activities than between days for a given person in general, either during working days or during the weekend. This is also the case for daily activity sequence. Finally, the influence of socio-demographic characteristics on intrapersonal variability is weak, whether for daily trips, tours, time use or activity sequence. The large level of intrapersonal variability in daily trip numbers already demonstrated in the literature is confirmed. Systematic day-to-day variability is shown to have an extremely low share in intrapersonal variability. The global picture is that intrapersonal variability is large while systematic day-to-day variability is marginal. Moreover, a striking result is that socio-demographic characteristics are mostly unable to explain the level of intrapersonal variability. The results reveal that individual behaviour is neither completely habitual nor completely random. On the one hand, intrapersonal variability is more important than the interpersonal one as regards daily trip numbers for the realization of mobility needs. On the other hand, activity time allocation and sequencing show an inverse trend, which can be linked with the habitual part of behaviour and the social role of the individual (through e.g. work, childcare and other activities).

For over 15 years, the subject of urban logistics has preoccupied many stakeholders, including both private and public decision-makers. The purpose of this paper is to present a study of the limits of public policy regulations restricting vehicle access to limited traffic zones to promote the use of urban consolidation centres (UCCs). After examining the main technical and economic aspects of implementing an UCC, we present the case of Vicenza (Italy), which has implemented very restrictive regulations. We study the municipal regulations and their legal consequences, by analysing court rulings issued between 2006 and 2009, following a lawsuit brought by an association of freight transport carriers due to these restrictions. Although this case seems applicable to a specific context, we identify several lessons that can be extrapolated to other cities. Therefore, the lessons drawn for other urban areas in Europe are presented, and their advantages and possible transferability studied.

Abstract In this paper we challenge the prevailing practice of conducting one‐off cross‐sectional mobility surveys, making a case for change on the basis of usefulness and cost‐effectiveness. We believe that urban areas over say, one million inhabitants, should collect mobility data on a continuous basis as part of their efforts to guarantee sustainable development. This would allow them to gain a proper understanding of the pressing environmental and transport‐related issues of today’s world, as well as of the effects of economic growth and price (especially for fuel) volatility. In our scope we include panel data (i.e. information from a smaller sample of respondents who are interviewed at different points in time, hopefully during several years), as this type of information is unique in its ability to help understanding behavioural changes and the impact of time‐related effects, such as habit and inertia. We revise the state of affairs in different parts of the world, not limiting ourselves to urban data.

Commonly collected data about urban freight does not provide appropriate input to urban freight transport policy-oriented models. According to us, a policy-oriented model (Ambrosini et al., 2008) is a data-adjusted model, oriented towards operational policy analysis. The aim is to simulate freight distribution within urban areas for evaluation, control and design of the urban freight transport system. Policy-oriented models help public decision making about the main stakes associated with an urban sustainable development. These models have to simulate the present situation properly enough to provide a good quality forecast to satisfy both local urban and global environmental issues. Data collected in order to calibrate those models have to fit into the methods carried out for their working. So we propose first doing a critical investigation of different possible methodological approaches for urban goods movement surveying. Secondly we present some recent approaches staying more close to reality, stressing on the necessary quality of data to improve the reliability of the results.

This book considers a range of contemporary approaches to public policy studies. These approaches are based on a number of theoretical perspectives on decision-making, as well as alternative perspecti

Collaborative transportation systems are relatively new concepts in research, but are very popular in practice. In the last years, collaborative transportation seems a good city logistics alternative to classical urban consolidation centers, but it is still in a development stage. This paper proposes a framework to define and evaluate collaborative urban transportation systems. This framework is organized in the following modules: a knowledge management system, a scenario simulator, a transportation management system, an environmental module, a risk factor estimation module and a multi-criteria decision support method. Finally, five realistic scenarios for the urban area of Lyon (France) are simulated and discussed to illustrate the proposed framework possible applications.