Mancini S.,Polytechnic University of Turin |
Gonzalez-Feliu J.,Laboratoire DEconomie des Transports
OPT-i 2014 - 1st International Conference on Engineering and Applied Sciences Optimization, Proceedings | Year: 2014
In this paper we introduce and formalize the Multi Depot Multi Period Vehicle Routing Problem with Heterogeneous Fleet and Drivers Scheduling Constraints (MDMPVRPHFDSC), a new Vehicle Routing Problem arising in real life context. The problem goal is to minimize a cost objective function which is given by a linear combination of traveling and driving costs. An heterogeneous fleet is considered, composed by vehicles with different capacity, characteristics (i.e. refrigerated vehicles) and usage cost. Drivers assignment to routes is ruled by their contracts constraints, that imposes a maximum number of driving hours per day, per couple of consecutive days and per week. Moreover, not every customer may be served by all the vehicles and from all the depots. Although most constraints of the problem have been broadly studied in literature, they have never been addressed together before. We propose a MIP formulation for the MDMPVRPHFDSC and computational tests carried out on instances with different characteristics.
Joumard R.,INRETS |
Nicolas J.-P.,Laboratoire DEconomie des Transports
Ecological Indicators | Year: 2010
Faced with a choice of different transport projects, such as road or rail infrastructure projects, which project is the most sustainable? We suggest a relatively simple and transparent evaluation method for such projects. First, transport issues within the sustainable development framework must be addressed, bearing in mind the strong meaning of the term, which is the only concept allowing environmental issues to be taken seriously into account. It also means linking local and global aspects, long and short terms, and thus to specify the time and geographical scales of projects and their impacts. Secondly, we put forward these main principles as evaluation criteria enabling the sustainable development concept to be made operational. We suggest three economic criteria, four social criteria and eleven environmental criteria, in addition to an aggregation method for these criteria integrating the social or political preferences of decision-makers or their representatives. A concern that is often significant in transport projects is the future of traffic mobility, whose main parameters we have analysed in order to put forward probable scenarios, which form the basis for applying the criteria listed above. © 2009 Elsevier Ltd. All rights reserved.
Gonzalez-Feliu J.,ISH Inc |
Ambrosini C.,ISH Inc |
Pluvinet P.,ISH Inc |
Toilier F.,Laboratoire DEconomie des Transports |
Routhier J.-L.,ISH Inc
Journal of Computational Science | Year: 2012
This paper proposes a novel approach in order to simulate the impacts of urban goods transport on road occupancy. It combines both inter-establishments flows and households' motorized shopping trips, as well as B2C flows. After a general description of the method resulting in an estimation of the movements, an actual example is implemented (city of Lyon, in France). Four scenarios are described and simulated, and then their results are compared. These results are promising and they take into account a large variety of flows (about 90% of the urban goods movement flows according to the classification of Patier, 2002). © 2012 Elsevier B.V.
Ambrosini C.,University of Lyon |
Gonzalez-Feliu J.,French National Center for Scientific Research |
Toilier F.,Laboratoire DEconomie des Transports
European Transport - Trasporti Europei | Year: 2013
Urban goods movement modelling is a popular subject in urban logistics research. However, most models remain under-used because practitioners have difficulties to apply them to simulate urban policies and their impacts on transport flows, mainly when the assessed situations are different from the initial usage of the mode. This paper aims to answer to that issue by proposing a methodology of scenario construction and assessment using current models and tools. The methodological contribution of the paper arises on defining the main elements of a policy-based scenario and on developing a procedure to build the inputs a model needs to simulate the impacts of policy-oriented strategies on urban goods transport flows. First, the main elements policy makers can take into account when defining middle term strategies are identified. Then, a scenario construction procedure is proposed, able to build reference scenarios and trend scenarios. An example for the urban area of Lyon is proposed. According to the reference scenario, it becomes possible to compare and understand urban goods movement changes, by implementing the model introducing variations, such as activity relocation or urban distribution centre whose impacts concern not only the freight flows themselves but also the whole urban logistics organisation. In this way, the proposed methodology is adapted to policy-oriented strategic and tactical planning, mainly for public stakeholders.
Vidaud M.,OXAND Inc |
Bernard O.,OXAND Inc |
Crouigneau S.,OXAND Inc |
Putallaz Y.,IMDM |
And 2 more authors.
WIT Transactions on the Built Environment | Year: 2012
This article presents three different ways of predicting investment needs to maintain and renew railway infrastructure. The 'Level 1' approach is based on financial ratios and does not take into account the infrastructure's history or maintenance strategies. This simplified approach can be used provided that the components age pyramid is uniform. The 'Level 2' approach considers the age pyramid's general impact without integrating budget constraints and possible specific optimization at the component level. This approach is useful and gives interesting rough estimates for macroscopic finance audits; it does not require an exhaustive knowledge of the owner's material assets. The advanced 'Level 3' approach enables planning of detailed investment needs on short, medium and long-term scales. It considers both physical and economic lifetimes for each component of the infrastructure as well as taking into account the budget constraints of the infrastructure's manager. It also allows the possibility of quantifying risks related to performance failure due to underinvestment. Using these different approaches, or cost models, with different European infrastructure managers enabled demonstration that investment needs and thus potential regulated returns (for regulated railway network management), strongly depend on infrastructure history and components age pyramid as well as physical and economic lifetimes. The article shows that management policy decisions and balance between renewal and maintenance, crucial in securing long-term network integrity (or 'substance') and in deciding on short-term investments, can be pre-modelled using advanced methods and tools to assess performance versus cost and risk over time. © 2012 WIT Press.