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A holding control strategy for diverging bus lines Laskaris, Georgios ; ; et al Scientific Conference (2018, July 24) We introduce a holding criterion for network configurations with lines that operate jointly along a common corridor and then individually diverge. The proposed holding decision rule accounts for all ... [more ▼] We introduce a holding criterion for network configurations with lines that operate jointly along a common corridor and then individually diverge. The proposed holding decision rule accounts for all different passengers groups in the overlapping segment and takes care of the transition to individual line operation. The holding rule is evaluated using simulation for different demand levels and segmentations and compared with other control schemes for a real-world network. Results show that gains in overall network performance as well as for specific passenger groups can be achieved under specific demand distributions. [less ▲] Detailed reference viewed: 89 (6 UL)Optimal multi-line bus dispatching at terminals with electric charging scheduling constraints Rinaldi, Marco ; ; et al Scientific Conference (2018, July) We consider the problem of optimally determining the sequence of electric and conventional internal combustion buses departing from a multi-line bus terminal, considering both service constraints ... [more ▼] We consider the problem of optimally determining the sequence of electric and conventional internal combustion buses departing from a multi-line bus terminal, considering both service constraints (schedule adherence) and energy constraints (electric bus charging status, bus recharging scheduling in capacitated facilities). The problem is formulated as a Mixed Integer Linear Program, with the objective of minimizing the total operational cost for the bus lines in question. System dynamics are captured by twenty sets of constraints, ranging from scheduling adherence to discharge-recharge dynamics. Individual operational costs at the bus level (cost of running an electric / non electric bus per km, cost of recharging) and at the trip level (penalty due to failed schedule adherence) are fully parametrised, allowing for extensive sensitivity analysis. We investigate a real-life case study based in the city of Luxembourg, where two charging stations have been installed in the central station’s bus terminal. Through the model we investigate: i) the minimum amount of electric buses necessary to perform a day’s schedule for two currently partially electrified lines, without resorting to conventional internal combustion alternatives; ii) the impact of electrifying two additional lines, specifically considering the trade-offs related to either adding new buses or new charging stations at the bus terminal. [less ▲] Detailed reference viewed: 167 (10 UL)Assessing the performance of coordinated predictive control strategies on urban-motorway networks Rinaldi, Marco ; Viti, Francesco in IFAC-PapersOnLine (2018, July), 51(9), 285-290 Coordination and integration of different traffic control policies have been of considerable interest in research in the last decades and, recently, have been object of large scale implementation trials ... [more ▼] Coordination and integration of different traffic control policies have been of considerable interest in research in the last decades and, recently, have been object of large scale implementation trials. In the setting of peri-urban motorway systems, coordination of various kinds of controllers must however be accompanied by accurate prediction of both propagation of flows and queues in the network, as well as the users’ response in terms of route choice. In this paper, we showcase through a real-life case study how coordination and prediction are both essential when performing hybrid urban-motorway control. Simulation results of a Model Predictive Control application are compared to simpler local control approaches, and the impact of coordinated intersection control and, additionally, Ramp Metering is evaluated. [less ▲] Detailed reference viewed: 90 (1 UL)Vulnerability analysis of network observability in link flow inference problems Rinaldi, Marco ; Viti, Francesco Scientific Conference (2018, January) Detailed reference viewed: 42 (0 UL)Multiline holding based control for lines merging to a shared transit corridor Laskaris, Georgios ; ; et al in Transportmetrica B: Transport Dynamics (2018) In transit corridors, multiple lines share a sequence of consecutive stops to provide higher joint frequency in higher demand areas. A key challenge is to coordinate the transition from single line to ... [more ▼] In transit corridors, multiple lines share a sequence of consecutive stops to provide higher joint frequency in higher demand areas. A key challenge is to coordinate the transition from single line to joint operation. A holding control strategy aimed at minimizing passenger travel times is introduced for lines merging into a shared corridor, accounting for the coordination of vehicle arrivals from the merging lines as well as the regularity of each line. The criterion is tested using an artificial network and a real-world network to analyze the impact of demand distribution and compare cooperative versus single line control. We illustrate how the real-time strategy yields overall passenger gains, depending on the composition of different user groups. Results are assessed based on operation and passenger performance indicators and show that coordination is achieved. When combined with joint control in the common part, the proposed approach achieves consistentnetwork-wide travel time benefits. [less ▲] Detailed reference viewed: 109 (5 UL)A global optimization heuristic for the decomposed static anticipatory network traffic control problem anticipatory network traffic control problem Rinaldi, Marco ; ; Viti, Francesco 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 ▲] Detailed reference viewed: 53 (2 UL)A local dynamic route and green time swapping control algorithm maximizing total network capacity Viti, Francesco ; Rinaldi, Marco 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 ▲] Detailed reference viewed: 106 (1 UL)On characterizing the relationship between route choice behavior and optimal traffic control solution space Rinaldi, Marco ; ; Viti, Francesco 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: 110 (2 UL)Exact and approximate route set generation for resilient partial observability in sensor location problems Rinaldi, Marco ; Viti, Francesco 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 ▲] Detailed reference viewed: 134 (4 UL)On characterizing the relationship between route choice behaviuor and optimal traffic control solution space Rinaldi, Marco ; ; Viti, Francesco 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 ▲] Detailed reference viewed: 120 (4 UL)Experimental analysis of eGLOSA and eGLODTA transit control strategies Giorgione, Giulio ; Viti, Francesco ; Rinaldi, Marco et al in Proceedings of the 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems, MT-ITS 2017 (2017) Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large ... [more ▼] Battery powered electric buses have higher energy efficiency, lower emissions and noise when compared to buses with internal combustion engines. However, due to battery charging requirements, their large-scale integration into public transport operations is more complex. This study proposes a novel concept supporting said integration via new control strategies, dubbed e-GLOSA and e-GLODTA. These strategies extend the existing Green Light Optimal Speed and Dwell Time Systems (GLOSA/GLODTA) to account for the specific needs of electric buses. That is, they include the goals of minimizing the energy consumption between charging stations, and maximizing available charging time. At the same time, interference with schedule requirements is minimized. The formulated heuristics are tested on a Bus Rapid Transit (BRT) corridor case study, where different scenarios—such as placement of charging stations and bus regularity—are studied to assess under which conditions each action (maintain speed, accelerate or dwell for a longer time at a stop) is beneficial. Results show that eGLOSA contributes to schedule adherence while eGLODTA allows satisfying charging time constraints. [less ▲] Detailed reference viewed: 202 (32 UL)A network-wide assessment of local signal control policies’ performance in practical implementations Cantelmo, Guido ; Viti, Francesco ; Rinaldi, Marco in Intelligent Transportation Systems (ITSC), 2016 IEEE 19th International Conference on (2016, November) Detailed reference viewed: 127 (9 UL)A PAS-state constrained optimization formulation for the anticipatory network traffic control problem Rinaldi, Marco ; Scientific Conference (2016, September) Detailed reference viewed: 123 (2 UL)Network observability information maximization through ad-hoc route enumeration approaches Rinaldi, Marco ; ; Viti, Francesco Scientific Conference (2016, June) Detailed reference viewed: 66 (2 UL)Improving the accuracy of OD estimation from traffic counts employing a partial observabillity maximizing methodology Rinaldi, Marco ; ; Viti, Francesco et al Scientific Conference (2016, January) Detailed reference viewed: 74 (1 UL)A sensitivity-based approach for adaptive decomposition of anticipatory network traffic control Rinaldi, Marco ; ; in Transportation Research. Part C : Emerging Technologies (2016), 66 Anticipatory optimal network control is defined as the problem of determining the set of control actions that minimizes a network-wide objective function. This not only takes into account local ... [more ▼] Anticipatory optimal network control is defined as the problem of determining the set of control actions that minimizes a network-wide objective function. This not only takes into account local consequences on the propagation of flows, but also the global network-wide routing behavior of the users. Such an objective function is, in general, defined in a centralized setting, as knowledge regarding the whole network is needed to correctly compute it. Reaching a level of centralization sufficient to attain network-wide control objectives is however rarely realistic in practice. Multiple authorities are influencing different portions the network, separated either hierarchically or geographically. The distributed nature of networks and traffic directly influences the complexity of the anticipatory control problem. This is our motivation for this work, in which we introduce a decomposition mechanism for the global anticipatory network traffic control problem, based on dynamic clustering of traffic controllers. Rather than solving the full centralized problem, or blindly performing a full controller-wise decomposition, this technique allows recognizing when and which controllers should be grouped in clusters, and when, instead, these can be optimized separately. The practical relevance with respect to our motivation is that our approach allows identification of those network traffic conditions in which multiple actors need to actively coordinate their actions, or when unilateral action suffices for still approximating global optimality. This clustering procedure is based on well-known algebraic and statistical tools that exploit the network's sensitivity to control and its structure to deduce coupling behavior. We devise several case studies in order to assess our newly introduced procedure's performances, in comparison with fully decomposed and fully centralized anticipatory optimal network control, and show that our approach is able to outperform both centralized and decomposed procedures. © 2016 Elsevier Ltd. [less ▲] Detailed reference viewed: 101 (3 UL)An extended coordinate descent method for distributed anticipatory network traffic control Rinaldi, Marco ; in Transportation Research. Part B : Methodological (2015), 80 Anticipatory optimal network control can be defined as the practice of determining the set of control actions that minimizes a network-wide objective function, so that the consequences of this action are ... [more ▼] Anticipatory optimal network control can be defined as the practice of determining the set of control actions that minimizes a network-wide objective function, so that the consequences of this action are taken in consideration not only locally, on the propagation of flows, but globally, taking into account the user's routing behavior. Such an objective function is, in general, defined and optimized in a centralized setting, as knowledge regarding the whole network is needed in order to correctly compute it. This is a strong theoretical framework but, in practice, reaching a level of centralization sufficient to achieve said optimality is very challenging. Furthermore, even if centralization was possible, it would exhibit several shortcomings, with concerns such as computational speed (centralized optimization of a huge control set with a highly nonlinear objective function), reliability and communication overhead arising.The main aim of this work is to develop a decomposed heuristic descent algorithm that, demanding the different control entities to share the same information set, attains network-wide optimality through separate control actions. © 2015 Elsevier Ltd. [less ▲] Detailed reference viewed: 101 (9 UL)Systematic assessment of local & global signal control policies: A methodological perspective Cantelmo, Guido ; Viti, Francesco ; Rinaldi, Marco et al in Proceedings of 2015 International Conference on Models and Technologies for Intelligent Transportation Systems, MT-ITS 2015 (2015) Traffic control performance on networks depends on the flow response to the policy adopted, which in turn contributes to determine the optimal signal settings. This paper focuses on the relationship ... [more ▼] Traffic control performance on networks depends on the flow response to the policy adopted, which in turn contributes to determine the optimal signal settings. This paper focuses on the relationship between local and network wide traffic control policies within the combined traffic control and assignment problem. Through a full exploration of the solution space, an in depth cross comparison is performed between the well-known local policies P0 and Equisaturation, versus the global policies Maximum Throughput and Minimum Delay, to verify how the two local policies approximate the optimal settings for signalized intersections. Realistic traffic dynamics, such as congestion, multiple controllers and spillback are considered, to empirically determine the conditions under which the local policies are able to approximate global performances. After presenting the different local and global control policies, experiments are performed on simple toy networks. The complexity of the underlying network and, therefore, of the problems' boundary conditions is then increased, allowing us to showcase how the different metrics perform in different situations. Finally, conclusions on the results are drawn. © 2015 BME. [less ▲] Detailed reference viewed: 43 (2 UL)An Integrated Perspective on Traffic Management and Logistic Optimization ; ; Rinaldi, Marco et al in Proceedings of the 18th IEEE International Conference on Intelligent Transportation Systems, ITSC 2015 (2015) Traffic Management and Logistic Optimization have been extensively studied as two separate classes of problems, for which numerous methodologies, mathematical models and algorithmic solutions were made ... [more ▼] Traffic Management and Logistic Optimization have been extensively studied as two separate classes of problems, for which numerous methodologies, mathematical models and algorithmic solutions were made available in literature. However, little attention has been devoted to the interactions between the variables involved in these problems and the consequences of the decision making processes carried independently by Traffic Managers and Logistic Players. We believe this to be of considerable importance, since partial or incomplete knowledge on one another's decisions might yield sub-optimality for either or both of them. In this work, we propose an integrated view on both classes of problems, providing mathematical formulations to support the assessment of the impact which the two players may have on each other. © 2015 IEEE. [less ▲] Detailed reference viewed: 84 (0 UL)Centralized and decomposed anticipatory Model Predictive Control for network-wide Ramp Metering Rinaldi, Marco ; ; et al in Proceedings of the 16th International IEEE Conference on Intelligent Transportation Systems: Intelligent Transportation Systems for All Modes, ITSC 2013 (2013) The problem of determining Ramp Metering control rates, taking into account routing response, is addressed in this paper. We develop Model Predictive Control based Anticipatory control schemes, featuring ... [more ▼] The problem of determining Ramp Metering control rates, taking into account routing response, is addressed in this paper. We develop Model Predictive Control based Anticipatory control schemes, featuring both centralized and decomposed optimization problems, with focus on real-life deployability. We then evaluate the aforementioned schemes' performances in comparison to simpler, non-anticipatory control techniques, by means of software simulation based on purpose-built experimental scenarios. © 2013 IEEE. [less ▲] Detailed reference viewed: 109 (0 UL) |
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