35 research outputs found

    A trip chain order model for simulating urban freight restocking

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    This paper proposes a trip chain order model for simulating retailer restocking within urban and metropolitan area. It is part of the general modelling system developed by the authors for simulating urban freight demand which considers both demand and logistic sub-systems. The former allows us to obtain the freight Origin-Destination (OD) matrices in quantities and deliveries per transport service type, time slice and vehicle type. The latter allows us to obtain the vehicle OD matrices according to the journey characteristics (i.e. number and sequence of delivery points) in order to restock economic activities located within the study area. This approach, known in literature as tour-based approach, aims at reproducing the choice structure of the restocking process and the sequence of delivery points (stops) for vehicle journeys, considering dependences existing among subsequent trips of the same journey. It implies that each destination zone to be delivered is chosen depending on the previous and the next destination ones. The logistic subsystem of the proposed modelling system can be divided in two parts: the first which defines the trip chain order (i.e. the number of deliveries made during a tour); the second one which considers the choice of the stop locations. This paper focuses on the specification and calibration of a trip chain order model using data collected in the city centre of Rome

    An aggregate transport demand model for import and export flow simulation

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    This paper presents a system of models for the estimation of international (import/export) freight flows through a partial share approach. It allows us to simulate attraction, production, distribution and modal split for the estimation of modal Origin-Destination matrices in quantities. Aiming at predicting long term effects for strategic planning, the modelling system has been specified through easy-to-capture variables represented by level-of-service attributes and aggregate socio-economic variables. The calibration was carried out by using a set of available data in Italy that allowed us to consider import/export flows for different freight types given by the aggregation of classes provided by European NST/R classifications. First published online: 25 Oct 201

    AN AGGREGATE TRANSPORT DEMAND MODEL FOR IMPORT AND EXPORT FLOW SIMULATION

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    This paper presents a system of models for the estimation of international (import/export) freight flows through a partial share approach. It allows us to simulate attraction, production, distribution and modal split for the estimation of modal Origin-Destination matrices in quantities. Aiming at predicting long term effects for strategic planning, the modelling system has been specified through easy-to-capture variables represented by level-of-service attributes and aggregate socio-economic variables. The calibration was carried out by using a set of available data in Italy that allowed us to consider import/export flows for different freight types given by the aggregation of classes provided by European NST/R classifications

    On Transport Monitoring and Forecasting during COVID-19 Pandemic in Rome

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    This paper presents the results of a study on the Rome mobility system aiming at estimating the impacts of the progressive lockdown, imposed by the government, due to the Covid-19 pandemic as well as to support decision makers in planning the transport system for the restart towards a post-Covid "new normal". The analysis of data obtained by the transport monitoring system has been fundamental for both investigating effects of the lockdown and feeding transport models to predict the impacts on future actions. At first, the paper focuses on the so-called transport analytics, by describing mobility trends for the multimodal transportation system of Rome. Then, the results of the simulated scenarios to design public transport services, able to ensure passengers social distancing required in the first post-Covid months, are presented and discussed

    Modelli di assegnazione alle reti di trasporto collettivo extraurbano

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    Dottorato di ricerca in ingegneria dei trasporti. 9. ciclo. A.a. 1995-96. Coordinatore O. Pavese. Tutore E. CascettaConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    The schedule-based modeling of transportation system: recent developments

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    This paper presents a concise state-of-the-art and some developments of the schedule-based modelling approach for the simulation of transportation systems. The overview on the evolution of the literature in this field is presented by authors considering, at first, theoretical issues and, then, algorithms, software and applications. A greater attention is made to public transport modelling, even if schedule-based models for other transportation systems, like freights, are also investigated
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