References of "Viti, Francesco 50003272"
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See detailA global optimization heuristic for the decomposed static anticipatory network traffic control problem anticipatory network traffic control problem
Rinaldi, Marco UL; Tampére, Chris; Viti, Francesco UL

in Transportation Research Procedia (2017)

Developing traffic control strategies taking explicitly into account the route choice behavior of users has been widely recognized irregularities in the solution space shape, such as non-convexity and non ... [more ▼]

Developing traffic control strategies taking explicitly into account the route choice behavior of users has been widely recognized irregularities in the solution space shape, such as non-convexity and non-smoothness. In this work, we propose an extended as a very challenging problem. Furthermore, the inclusion of user behavior in optimization based control schemes introduces strong decomposition scheme for the anticipatory traffic control problem, based upon our previous contributions, which aims at i) reducing irregularities in the solution space shape, such as non-convexity and non-smoothness. In this work, we propose an extended the computational complexity of the problem by approaching it in a controller-by-controller fashion, and ii) internalizing specific decomposition scheme for the anticipatory traffic control problem, based upon our previous contributions, which aims at i) reducing constraints in the objective function, guiding the optimization process away from non-significant minima, such as flat regions. the computational complexity of the problem by approaching it in a controller-by-controller fashion, and ii) internalizing specific Through two small scale test networks and different, randomly chosen initial points, we compare how the proposed extension constraints in the objective function, guiding the optimization process away from non-significant minima, such as flat regions. influences optimization results with respect to our previously developed decomposed approach, as well as centralized schemes. Through two small scale test networks and different, randomly chosen initial points, we compare how the proposed extension influences optimization results with respect to our previously developed decomposed approach, as well as centralized schemes. [less ▲]

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See detailDemo: MAMBA: A Platform for Personalised Multimodal Trip Planning
Faye, Sébastien UL; Cantelmo, Guido UL; Tahirou, Ibrahim UL et al

Software (2017)

In recent years, multimodal transportation has become a challenging approach to route planning. Most existing planning systems usually rely on data sourced from different organisations, enabling the user ... [more ▼]

In recent years, multimodal transportation has become a challenging approach to route planning. Most existing planning systems usually rely on data sourced from different organisations, enabling the user to select a limited number of routing strategies. As part of the MAMBA project, developed in Luxembourg until 2017, we have been interested in the potential benefits of multimodal mobility systems. A key factor has been integrated into our studies: the need for a personalised experience at user level, whether when selecting the means of transport or describing user habits (e.g. route style, environment). In this context, we have developed a platform for planning personalised multimodal trips, broken down into the three main modules presented in this demonstration. More importantly, this platform has been developed to facilitate the daily mobility of people in Luxembourg, and considers datasets and characteristics that are specific to this region, which has an exceptionally high volume of daily commuting between Luxembourg and neighbouring countries. [less ▲]

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See detailEstimating Urban Road Traffic States Using Mobile Network Signaling Data
Derrmann, Thierry UL; Frank, Raphaël UL; Viti, Francesco UL et al

in Abstract book of the 20th International Conference on Intelligent Transportation Systems (2017, October)

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used ... [more ▼]

It is intuitive that there is a causal relationship between human mobility and signaling events in mobile phone networks. Among these events, not only the initiation of calls and data sessions can be used in analyses, but also handovers between different locations that reflect mobility. In this work, we investigate if handovers can be used as a proxy metric for flows in the underlying road network, especially in urban environments. More precisely, we show that characteristic profiles of handovers within and between clusters of mobile network cells exist. We base these profiles on models from road traffic flow theory, and show that they can be used for traffic state estimation using floating-car data as ground truth. The presented model can be beneficial in areas with good mobile network coverage but low road traffic counting infrastructure, e.g. in developing countries, but also serve as an additional predictor for existing traffic state monitoring systems. [less ▲]

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See detailThe effect of workplace relocation on individuals’ activity travel behaviour
Sprumont, François UL; Viti, Francesco UL

Scientific Conference (2017, July 04)

During working days, home and workplace are anchor locations shaping the daily mobility as well as the employee’s activity pattern. While past research has shown that workplace decentralization is often ... [more ▼]

During working days, home and workplace are anchor locations shaping the daily mobility as well as the employee’s activity pattern. While past research has shown that workplace decentralization is often associated with higher car use for the commuting trip, little is known concerning the effect on activity-travel patterns as whole. The objective of this paper is to assess how workplace decentralization is affecting individuals’ daily activity space. A two-weeks travel diary has been filled by 43 employees of the University of Luxembourg, both before and after the relocation of their workplace. Using descriptive statistics, as well as Standard Deviational Ellipses (SDE) combined with a cluster analysis, results of this paper show that workers’ activity spaces, represented by the Standard Deviational Ellipses, have been importantly modified due to a relocation of a single anchor activity location, i.e. their workplace [less ▲]

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See detailEffectiveness of the Two-Step Dynamic Demand Estimation model on large networks
Cantelmo, Guido UL; Viti, Francesco UL; Derrmann, Thierry UL

in Proceedings of 2017 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS) (2017, June 28)

In this paper, the authors present a Two-Step approach that sequentially adjusts generation and distribution values of the (dynamic) OD matrix. While the proposed methodology already provided excellent ... [more ▼]

In this paper, the authors present a Two-Step approach that sequentially adjusts generation and distribution values of the (dynamic) OD matrix. While the proposed methodology already provided excellent results for updating demand flows on a motorway, the aim of this paper is to validate this conclusion on a real network: Luxembourg City. This network represents the typical middle-sized European city in terms of network dimension. Moreover, Luxembourg City has the typical structure of a metropolitan area, composed of a city centre, ring, and suburb areas. An innovative element of this paper is to use mobile network data to create a time-dependent profile of the generated demand inside and outside the ring. To support the claim that the model is ready for practical implementation, it is interfaced with PTV Visum, one of the most widely adopted software tools for traffic analysis. Results of these experiments provide a solid empirical ground in order to further develop this model and to understand if its assumptions hold for urban scenarios. [less ▲]

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See detailHow Mobile Phone Handovers reflect Urban Mobility: A Simulation Study
Derrmann, Thierry UL; Frank, Raphaël UL; Engel, Thomas UL et al

in Proceedings of the 5th IEEE Conference on Models and Technologies for Intelligent Transportation Systems. (2017, June 26)

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See detailGenerating purpose-dependent production factors through Monte Carlo sampling techniques.
Scheffer, Ariane; Cantelmo, Guido UL; Viti, Francesco UL

Scientific Conference (2017, May)

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See detailDiscussion on cross-border integration using non-dominant mobility flows
Sprumont, François UL; Viti, Francesco UL

Scientific Conference (2017, April 12)

On the edge of two different countries, cross-border regions exhibit very peculiar features. While borders can be seen as an interface or a barrier, analyze the interactions between two sovereign spatial ... [more ▼]

On the edge of two different countries, cross-border regions exhibit very peculiar features. While borders can be seen as an interface or a barrier, analyze the interactions between two sovereign spatial entities is extremely important for political reasons, economical development, land use management, etc. Because of data availability issues, spatial cross-border integration is mostly characterized using cross-border workers commuting flow information, or more rarely, by using activities performed by cross-border workers in the country they work. Despite its small size (2586 km2), the Grand-duchy of Luxembourg is a strong economic locomotive. Among the 380 000 available jobs in the country, 42% are occupied by cross border workers from France, Belgium and Germany. While the commuting behavior and the activity chains of the cross border workers have been largely studied this is not the case for the population living in Luxembourg. This study, using two weeks of travel diary data of 35 staff members of the University of Luxembourg living in the Grand-Duchy of Luxembourg, aims at analyzing the relationship that the respondents have with borders. Our hypothesis is that cross-border integration characterization would gain in robustness if non-dominant centripetal flows were taken into account as well. [less ▲]

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See detailOn the consistency between commuting satisfaction and traveling utility: the case of the University of Luxembourg
Sprumont, François UL; Astegiano, Paola; Viti, Francesco UL

in European Journal of Transport and Infrastructure Research (2017), 17(2), 248-262

According to random utility theory, there is no clear distinction between the utility inferred from observed choices (decision utility), the experienced outcome of decision makers’ (experienced utility ... [more ▼]

According to random utility theory, there is no clear distinction between the utility inferred from observed choices (decision utility), the experienced outcome of decision makers’ (experienced utility) or their retrospective evaluation (remembered utility). While empirical experiments have shown that decision utility and remembered utility do not perfectly coincide, little is known regarding the magnitude of this discrepancy, especially in the transport field. Using a cross-sectional travel survey, the objective of this paper is to quantify the relationship between commuters’ stated choice satisfaction (a proxy for remembered utility) and the Logsum function of the utility of all available modes of transport (decision utility). This is of tremendous importance, as implemented transport policy measures, which aim to increase the overall decision makers’ utility, may have low impact on their satisfaction level and thus be ineffective. Results indicate that the utility Logsum is associated with respondents’ commuting satisfaction. However, context specificities have an important impact on this association. [less ▲]

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See detailUsage of Smartphone Data to Derive an Indicator for Collaborative Mobility between Individuals
Toader, Bogdan UL; Sprumont, François UL; Faye, Sébastien UL et al

in ISPRS International Journal of Geo-Information (2017), 6(3), 62

The potential of geospatial big data has been drawing attention for a few years. Despite the larger and larger market penetration of portable technologies (nomadic and wearable devices like smartphones ... [more ▼]

The potential of geospatial big data has been drawing attention for a few years. Despite the larger and larger market penetration of portable technologies (nomadic and wearable devices like smartphones and smartwatches), their opportunities for travel behavior analysis are still relatively unexplored. The main objective of our study is to extract the human mobility patterns from GPS traces in order to derive an indicator for enhancing Collaborative Mobility (CM) between individuals. The first step, extracting activity duration and location, is done using state-of-the-art automated recognition tools. Sensors data are used to reconstruct individual’s activity location and duration across time. For constructing the indicator, in a second step, we defined different variables and methods for specific case studies. Smartphone sensor data are being collected from a limited number of individuals and for one week. These data are used to evaluate the proposed indicator. Based on the value of the indicator, we analyzed the potential for identifying CM among groups of users, such as sharing traveling resources (e.g., carpooling, ridesharing, parking sharing) and time (rescheduling and reordering activities). [less ▲]

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See detailAnalyzing the relation between commuting satisfaction and residential choices using discrete choice theory and structural equation modeling
Sprumont, François UL; Astegiano, Paola; Viti, Francesco UL

Poster (2017, January)

The concept of travelling satisfaction is gaining more and more interest in the transportation field. While increasing travellers’ satisfaction should be a goal of policy makers and practitioners, a drop ... [more ▼]

The concept of travelling satisfaction is gaining more and more interest in the transportation field. While increasing travellers’ satisfaction should be a goal of policy makers and practitioners, a drop in commuting satisfaction might lead to switch from one mode to another. Objective trip characteristics (time, cost, mode) as well as other elements such as mode attitude, lifestyle, etc. affect travel satisfaction rating. Despite an extensive literature on travel satisfaction determinants, often, the interaction between the studied determinants is overlooked. The main aim of this paper is to quantify the impact (both direct and indirect) of residential choices on the home-to-work stated travelling satisfaction. Methodologically, a Discrete Choice Theory approach (via the well-known concept of the utility Logsum) and a Partial Least Square Structural Equation Modelling (PLS-SEM) approach have been used and compared. Results of both modelling approaches show that the direct effect of residential choices on commuting satisfaction is negligible compared to individuals’ external factors such as trip characteristics. However, using the PLS-SEM approach, indirect effects of residential choices on commuting satisfaction can be quantified [less ▲]

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See detailAn iterative learning approach for anticipatory traffic signal control on urban networks
Huang, Wei; Viti, Francesco UL; Tampere, Chris

in Transportmetrica B: Transport Dynamics (2017), 5(4), 407-430

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See detailOn characterizing the relationship between route choice behaviuor and optimal traffic control solution space
Rinaldi, Marco UL; Tampère, C. M. J.; Viti, Francesco UL

in Transportation Research. Part B : Methodological (2017)

Explicitly including the dynamics of users' route choice behaviour in optimal traffic control applications has been of interest for researchers in the last five decades. This has been recognized as a very ... [more ▼]

Explicitly including the dynamics of users' route choice behaviour in optimal traffic control applications has been of interest for researchers in the last five decades. This has been recognized as a very challenging problem, due to the added layer of complexity and the considerable non-convexity of the resulting problem, even when dealing with simple static assignment and analytical link cost functions. In this work we establish a direct behavioural connection between the different shapes and structures emerging in the solution space of such problems and the underlying route choice behaviour. We specifically investigate how changes in the active equilibrium route set exert direct influence on the solution space's structure and behaviour. Based on this result, we then formulate and validate a constrained version of the original problem, yielding desirable properties in terms of solution space regularity. © 2017. [less ▲]

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See detailNovel C-ITS support for Electric Buses with Opportunity Charging
Seredynski, Marcin; Viti, Francesco UL

in Proceedings of IEEE-ITS Conference (2017)

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See detailExact and approximate route set generation for resilient partial observability in sensor location problems
Rinaldi, Marco UL; Viti, Francesco UL

in Transportation Research. Part B : Methodological (2017), 105

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a ... [more ▼]

Sensor positioning is a fundamental problem in transportation networks, as the location of sensors strongly determines how traffic flows are observable and hence manageable. This paper aims to develop a methodology to determine sensor locations on a network such that an optimal trade-off solution is found between the amount of sensors installed and the resilience of the sensor set. In particular, we propose exact and heuristic solutions for identifying the optimal route sets such that no other route would include any additional information for finding optimal full and partial observability solutions. This is an important contribution to sensor location problems, as route-based link flow inference problems have non-unique solutions, strongly depending on the used link-route information. The properties of the new methodology are analyzed and illustrated through different case studies, and the advantages of the algorithms are quantified both for full and for partial observability solutions. Due to the route sets found by our approach, we are able to find full observability solutions characterized by a small number of sensors, while yet being efficient also in terms of partial observability. We perform validation tests on both small and real-life sized network instances. © 2017 Elsevier Ltd [less ▲]

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See detailA New Modelling Framework over Temporal Graphs for Collaborative Mobility Recommendation Systems
Toader, Bogdan UL; Moawad, Assaad UL; Fouquet, François UL et al

Scientific Conference (2017)

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data ... [more ▼]

Over the years, collaborative mobility proved to be an important but challenging component of the smart cities paradigm. One of the biggest challenges in the smart mobility domain is the use of data science as an enabler for the implementation of large scale transportation sharing solutions. In particular, the next generation of Intelligent Transportation Systems (ITS) requires the combination of artificial intelligence and discrete simulations when exploring the effects of whatif decisions in complex scenarios with millions of users. In this paper, we address this challenge by presenting an innovative data modelling framework that can be used for ITS related problems. We demonstrate that the use of graphs and time series in multi-dimensional data models can satisfy the requirements of descriptive and predictive analytics in real-world case studies with massive amounts of continuously changing data. The features of the framework are explained in a case study of a complex collaborative mobility system that combines carpooling, carsharing and shared parking. The performance of the framework is tested with a large-scale dataset, performing machine learning tasks and interactive realtime data visualization. The outcome is a fast, efficient and complete architecture that can be easily deployed, tested and used for research as well in an industrial environment. [less ▲]

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See detailA local dynamic route and green time swapping control algorithm maximizing total network capacity
Viti, Francesco UL; Rinaldi, Marco UL

in Proceedings of the 25th Mediterranean Conference on Control and Automation, MED 2017 (2017)

This paper deals with the traffic signal control problem. More specifically it investigates the impact at a network level of simple dynamic local traffic control policies. A dynamic route swapping rule is ... [more ▼]

This paper deals with the traffic signal control problem. More specifically it investigates the impact at a network level of simple dynamic local traffic control policies. A dynamic route swapping rule is adopted to model the behavioral response of the travellers to signal changes, while a dynamic signal control swapping rule based on an equi-pressure policy is used to implicitly consider the flow response within the control updating process. Results on a simple network show that the flow responsive control policy outperforms pre-timed control, as well as a more conventional local control policy based on signal equi-saturation. Numerical results show also that the swapping rule based on equi-pressure is less susceptible to local optima, to systematically improve total network throughput, and to increase its effectiveness with when demand increases. © 2017 IEEE. [less ▲]

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See detailOn characterizing the relationship between route choice behavior and optimal traffic control solution space
Rinaldi, Marco UL; Tampère, C. M. J.; Viti, Francesco UL

in Transportation Research Procedia (2017), 23

Explicitly including the dynamics of users' route choice behaviour in optimal traffic control applications has been of interest for researchers in the last five decades. This has been recognized as a very ... [more ▼]

Explicitly including the dynamics of users' route choice behaviour in optimal traffic control applications has been of interest for researchers in the last five decades. This has been recognized as a very challenging problem, due to the added layer of complexity and the considerable non-convexity of the resulting problem, even when dealing with simple static assignment and analytical link cost functions. In this work we establish a direct behavioural connection between the different shapes and structures emerging in the solution space of such problems and the underlying route choice behaviour. We specifically investigate how changes in the active equilibrium route set exert direct influence on the solution space's structure and behaviour. Based on this result, we then formulate and validate a constrained version of the original problem, yielding desirable properties in terms of solution space regularity. © 2017 The Authors. [less ▲]

Detailed reference viewed: 21 (2 UL)