Andrea D'Ariano

• Doctor of Engineering
• Full Professor at Roma Tre University

Optimization models for railway traffic rescheduling tackle the problem of determining, in real-time, control actions to reducing the effect of disturbances in railway systems. In this field, mainly two research streams can be identified. On the one hand, train scheduling models are designed to include all conditions relevant to feasible and effici...

In the last years, railway companies are experiencing increasing difficulties to face the ever increasing transport demand while ensuring good quality of service to passengers, also due to the limited space and funds to build new infrastructure in bottleneck areas. These facts stimulated the interest for new effective OR solutions for real-time tra...

Intelligent decision support systems for the real-time management of landing and takeoff operations can be very effective in helping traffic controllers to limit airport congestion at busy terminal control areas. The key optimization problem to be solved to this aim can be formulated as a mixed integer linear program. However, since this problem is...

This paper deals with the real-time problem of scheduling and routing trains in a railway network. In the related literature, this problem is usually solved starting from a subset of routing alternatives and computing the near-optimal solution of the simplified routing problem. We study how to select the best subset of routing alternatives for each...

This work addresses the real-time optimization of takeoff and landing at a busy terminal control area in case of traffic congestion. These areas are becoming the bottleneck of the entire air traffic control system, in particular in the major European airports, where there is limited possibility to build new infrastructure. This problem is particula...

The goal of Railcar Itinerary Optimization in Marshalling Yards (RIO-MY) is to achieve an effective integrated operation plan for both train shunting operations and train makeup, with the aim of minimizing the railcar dwell time in the railway marshalling yard. Due to complex interdependent decisions in the disassembly and assembly process of train...

In a railway shunting yard, the transformation of inbound trains into properly composed outbound trains is a complex task because it involves decisions of multiple operations processes. This study addresses the integrated optimization of hump sequencing, train makeup, and classification track assignment problem in a railway shunting yard. Several k...

Train breakdowns have significant negative impacts on metro systems and passengers. In this context, the implementation of a train-to-train rescue serves as a crucial mechanism to restore operations promptly. This paper proposes a train rescheduling approach in the case of a train breakdown, incorporating a train-to-train rescue on a metro line. Th...

Iron ore has had a highly global market since setting a new pricing mechanism in 2008. With current dollar values, iron ore concentrate for sale price, which was $39 per tonne (62% Fe) in December 2015, reached $218 per tonne (62% Fe) in mid-2021. It is hovering around $120 in October 2023 (cf. https://tradingeconomics.com/commodity/iron-ore). The...

The promotion of multimodal coordination is of great significance for the joint development of diverse urban transportation systems. Focusing on a comprehensive urban passenger transport hub that converges both intercity modes and multiple inner-city modes, our study aims to incorporate intercity railway and Metrorail coordination into train schedu...

This study introduces a decision support framework that integrates aircraft trajectory optimization and arrival scheduling to facilitate efficient management of descent operations for arriving aircraft within terminal maneuvering areas. The framework comprises three modules designed to tackle specific challenges in the descent process. The first mo...

Since the inception of the China–Europe Railway Express (CRE), rail transportation has emerged as a predominant means of transporting goods across international borders. The quality and reliability of railway transport services are constrained by the precision of train travel times. However, the real-time data available for the CRE trains is rather...

The optimization of shunting operations has been recognized as a cost-effective measure for rail companies, but its impact on rolling stock management has not been fully explored. Previous research on shunting operations has often focused on operational decisions, neglecting the effect of maintenance scheduling activities in an integrated approach....

In the stockyard of dry bulk materials such as coal and iron ore, multiple stacker-reclaimers operate collaboratively to enhance stockyard productivity. However, effectively planning the routes for these interconnected machines presents a significant challenge. We propose a new modeling framework for this conflict-free routing problem in which the...

Automatic heavy-haul train (HHT) operation technology has recently received considerable attention in the field of rail transportation. In this paper, a discrete-time-based mathematical formulation is proposed to address the speed profile optimization problem in order to ensure the safe, efficient, and economical operation of heavy-haul trains (HHT...

Recognizing the pressure on urban logistics and the overcapacity of urban public transportation systems during off-peak hours, this study investigates a subway-assisted delivery model. This is a system in which part of the goods to be delivered into a city can be transferred to specific subway stations in advance (e.g., during the night) using unde...

Due to the complex network structure and time-varying spatial relationships inherent in metro station systems, coupled with the influence of historical time series, station-level passenger flow forecasting tasks are challenging to solve by traditional prediction models. Therefore, we propose a dynamic relational graph convolutional network that inc...

A train platforming problem (TPP) involves assigning platforms and routes to trains according to the train timetable in a rail station yard. However, locomotive operations not included in the TPP – such as replacing locomotives for trains – can lead to additional decision-making challenges for dispatchers and potentially result in scheduling confli...

Despite rail’s growing popularity as a mode of freight transportation due to its role in intermodal transportation and numerous economic and environmental benefits, optimizing all aspects of rail infrastructure use remains a significant challenge. To address this issue, various methods for developing train disruption prediction models have been use...

In metro system, the fault of traction power supply system may cause the power supply shortage around the failure substation. In this case, the dispatching measure should be immediately taken to reduce the impacts of disruption on the train operation. To deal with this real-time traffic management problem, a cooperative control approach is proposed...

Most of the existing path planning methods of automated guided vehicles (AGVs) are static. This paper proposes a new methodology for the path planning of a fleet of AGVs to improve the flexibility, robustness, and scalability of the AGV system. We mathematically describe the transport process as a dynamical system using an ad hoc mixed logical dyna...

Operations of Automated Guided Vehicles (AGVs) are desired to be more energy-efficient while maintaining high transport productivity, motivated by the green production requirements. This paper investigates a new energy-efficient planning problem for determining conflict-free paths of the AGVs in its transport roadmap. In this problem, the vehicle p...

Traditionally, traffic congestion was alleviated through significantly upgrading the infrastructure of transportation networks. However, building new roads or adding more lanes to a main road needs huge expenses. A better cost-effective approach is to redesign and fine-tune transportation networks by closing and reversing existing lanes. This paper...

Continuous Descent Operation (CDO), an aircraft arrival procedure in which an aircraft descends from an optimal position with minimum engine thrust, can significantly reduce aircraft noise, fuel burn and emissions. The implementation of CDOs, however, requires more separation buffers among flights than traditional stepwise descents, resulting in lo...

Extended Abstract Transportation plays a fundamental role in carbon emissions, with its impact recently estimated at about 1/4th of all energy-related CO2 emissions worldwide (Creutzig et al., 2015). Moreover, its growth outpaces that of most industrial sectors, following constantly increasing demand for transport for both people and goods. Electri...

To ensure a safe and regular train service, rail infrastructure managers periodically and with large advance design timetables. However, train schedules and operations are subordinated to a large number of parameters, making them vulnerable to service disturbances. The dispatchers are thus required to quickly detect new conflicts arising during ope...

This paper investigates a new lane reservation problem with task merging that consists of optimally determining which lanes in a transportation network have to be reserved and designing reserved lane-based routes in the network for time-crucial transport tasks. Part of the tasks whose destinations are geographically close is merged to reduce the nu...

Railway traffic management focuses on regulating train movements and delivering improved service quality to passengers; however, such efforts are subject to many uncertainties in terms of disruptions and passenger demand on a rail transit line. In contrast to most existing studies, which focus on the rescheduling of passenger timetables in a determ...

This repository includes the computational results, source codes and source data (with no conflict of interest) for the experiments presented in the paper.

In recent years the concept of virtual coupling, where multiple train units are virtually coupled into a platoon with very short following distances, has received considerable attention in the railway transportation field. This study introduces this concept into the train scheduling problem to improve line capacity and reduce congestion in urban me...

The Crew Scheduling Problem (CSP) is an important and difficult problem in railway crew management. In this paper, we focus on the railway crew scheduling problem with time window constraints caused by meal break rules. To address these complex crew scheduling rules, we construct a Time-Space-State Network (TSSN), formulate the studied problem as a...

This paper investigates a novel routing problem of a multi-robot station in a manufacturing cell. In the existing literature, the objective is to minimize the cycle time or energy consumption separately. The routing problem considered in this paper aims to reduce the cycle time and energy consumption jointly for each robot while avoiding collisions...

In this paper, a new time-space network model is proposed for addressing the time-dependent rural postman problem (TDRPP) of a single vehicle. The proposed model follows the idea of arc-path alternation to form a feasible and complete route. Based on the proposed model, the time dependency of the TDRPP is better described to capture its dynamic pro...

By 2050, Europe hopes to nearly double the freight traffic train in order to achieve carbon neutrality. One of the challenges that the multimodal freight transport will face is related to optimizing the high costs associated with the management of rolling stock. In this context, we study an integration of the maintenance constraint for the Rolling...

The real-time Railway Traffic Management Problem (rtRTMP) is the problem of detecting and solving time-overlapping conflicting requests made by multiple trains on the same track resources. This problem consists in retiming, reordering and rerouting trains in such a way that the propagation of disturbances in the railway network is minimized. The rt...

In high-speed rail networks, train units are scheduled to periodically meet all maintenance requirements while at the same time continuing to serve all scheduled passenger trips. Motivated by the trip demand variances on the days of every week in China, this paper studies a weekly rolling stock planning (W-RSP) problem that aims to optimize the rot...

Abstract. Tracks operations, such as shunting operations, require specialized machinery often equipped with large-volume compression-ignition internal combustion engines with high power outputs. This involves significant fuel consumption and emission of harmful pollutants in the exhaust gases which often do not meet any emission standards and gener...

This paper addresses the real-time train regulation problem by taking the stop-skipping strategy into account in high-frequency urban rail transit lines. During rush hours, if the train regulation is not adopted properly and rapidly to deal with the frequent disturbances, the delays may further spread and result in a large number of passengers stra...

The real-time Train Routing Selection Problem (rtTRSP) is the combinatorial optimization problem of selecting, for each train in a rail network, the best routing alternatives. Solving the rtTRSP aims to limit the search space of train rescheduling problems, highly affected by the number of routing variables. The rtTRSP is modelled as the minimum we...

More and more unexpected events occur in metro systems, which may cause serious disturbances and even disruptions for the operation of trains. This paper studies an integrated train rescheduling and rolling stock circulation planning problem for the complete blockage situations in a metro line. We consider several key practical train operation cons...

Continuous Descent Operation (CDO), an arrival procedure with low engine thrust settings or a low drag configuration, is playing a significant role in reducing fuel consumption, gas emission and noise for aircraft descending operations. In a busy Terminal Maneuvering Area (TMA) which usually have extremely high air traffic demand and severe congest...

The activity segment of wagon load - block train has declined significantly in the past years and its significant growth potential can only be fully achieved through automated solutions in order to speed up and reduce costs in the rail freight operations, achieving long-term economies of scale. In this context, this study examines the effect of dif...

We investigate the energy-efficient train timetabling and rolling stock circulation planning problem for metro lines based on flexible selections of train operation levels, which involve running levels (various running times and speed profiles) and dwell levels (various dwell times at stations). The travel demand of passengers is involved in the en...

During railway operations unexpected events may occur, influencing normal traffic flows. This paper focuses on a train rescheduling problem in a railway system with seat-reserved mechanism during large disruptions, such as a rolling stock breakdown leading to some canceled services, where passenger reassignment strategies have also to be considered...

Energy consumption is expected to be reduced while maintaining high productivity for container handling. This paper investigates a new energy-efficient scheduling problem of automated container terminals, in which quay cranes (QCs) and lift automated guided vehicles (AGVs) cooperate to handle inbound and outbound containers. In our scheduling probl...

Subway lines connecting different urban functional zones in large cities have direction-dependent and time-variant passenger demand, namely, asymmetry in passenger demand. Most existing studies adopt a symmetric strategy to design operations in both directions and sequentially optimize the different problems associated with operations, thereby fail...

An important objective for train operating companies is to let users, especially commuters, directly query the ICT system about trains’ availability calendar, based on an online approach, and give them clear and brief information, expressed through “intelligent” phrases instead of bit maps. This paper provides a linear programming model of this pro...

This paper investigates an integrated rolling stock deadhead routing and timetabling problem from the rolling stock scheduling in a complicated urban rail transit line. Given the train sequences composed of passenger train trips within an operation day, the deadhead routing sub-problem aims at selecting the rolling stock deadhead routes between the...

We investigate the train timetabling problem in suburban rail transit lines by considering (1) the traditional stopping mode (TSM), in which all trains stop at each station, and (2) the express/local stopping mode (ELM), in which express trains can skip certain low-demand stations. We first propose two mixed-integer linear programming models for th...

During railway operations, unexpected events may influence normal traffic flows. This paper focuses on a train rescheduling problem for handling large disruptions, such as a rolling stock breakdown leading to a cancelled train service, where passenger reassignment strategies have to be considered. A novel mixed-integer linear programming formulatio...

With the expansion of urban rail networks and the increase of passengers demand, the coordination of strongly connected lines becomes more and more important, because passengers transfer several times during their trips and major transfer stations in the rail network often suffer from over-crowdedness, especially during peak-hours. In this paper, w...

This paper presents a timetable-based approach to assess the capacity of a railway freight node, based on the microscopic simulation and saturation of the timetable. Saturation is done by scheduling additional saturation train paths without introducing any traffic conflict, while respecting the required technical and operational constraints, until...

This paper analyses how train delays propagate in a metro network due to disturbances and disruptions when different recovery strategies are implemented. Metro regulators use traffic management policies to recover from delays as fast as possible, return to a predefined schedule, or achieve an expected regularity of train arrivals and departures. We...

The real-time Railway Traffic Management Problem (rtRTMP) is the problem of detecting and solving time-overlapping conflicting request done by multiple trains on the same track resources. It typically consists in taking retiming, reordering or rerouting train actions in such a way that the propagation of disturbances in the railway network is minim...

Partitioning a large network into multiple subnetworks is adopted extensively in various practical applications involving the architecture of distributed management. In this study, we consider strategic simultaneous node and link districting to partition the nodes and links of a given transportation network into a fixed number of mutually disjoint...

This paper describes a new approach to develop a real-world automated scheduler applicable for Australian sugarcane industry. In Australia, the transport sector plays a critical role in raw sugarcane harvest and accounts for over 35% of the total cost of raw sugar production. The generation of an optimised schedule can bring the following practical...

Public transport services are currently executing or planning a fundamental transition from traditional buses to electric buses. During this transition phase, the public transport offering is fulfilled with a mixed fleet across multiple bus terminals, which poses operational challenges for optimal vehicle scheduling, a problem not yet addressed in...