International Journal of Computational Science and Engineering 26(5), pp. 505-512, 2023
After the separation of rail infrastructure managers from rail service operators occurred within ... more After the separation of rail infrastructure managers from rail service operators occurred within the European Union in 1991, the necessity of defining an access charge framework for ensuring non-discriminatory access to the rail market arose. Basically, it has to guarantee an economic balance for infrastructure manager accounts. Currently, in the Italian context, access charge schemes neglect the actual energy-consumption of rail operators and related costs of energy traction for infrastructure managers. Therefore, we propose a methodology, integrating cloud-based tasks and simulation tools, for including such an aspect within the infrastructure toll, thus making the system more sustainable. Finally, to show the feasibility of the proposed approach, it has been applied to an Italian real rail context, i.e. the Rome-Naples high-speed railway line. Results have shown that customising the tool access charges, by considering the power supply required, may generate a virtuous loop with an increase in energy-efficiency of rail systems.
Proceedings of the 6th International Conference of Contemporary Affairs in Architecture and Urbanism (ICCAUA 2023), Istanbul, Türkiye, June 2023, 2023
Smart and green mobility systems are key factors for the sustainability of our cities which are e... more Smart and green mobility systems are key factors for the sustainability of our cities which are experiencing increasingly growing density conditions. The goal is to make public and sharing transport systems more attractive than private vehicles, thus reducing congestion levels as well as air and noise pollution in favour of the quality of life in our urban and suburban areas. In this context, the proposed paper presents a simulation-based methodology for increasing the efficiency level of railway operations, through the implementation of virtual coupling systems, intending to lead the modal split towards a more sustainable scenario. To show the feasibility of the proposed approach, it has been applied in the case of a real regional rail line. Results confirm the benefits of the adoption of such systems on the attractiveness levels by showing an increase in carrying capacity with a related reduction in user waiting times.
Proceedings of the 23rd IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2023) and 7th Industrial and Commercial Power Systems Europe (I&CPS 2023), Madrid, Spain, June 2023, 2023
Rail transport is one of the most sustainable transportation systems since it requires the use of... more Rail transport is one of the most sustainable transportation systems since it requires the use of smaller unitary energy resources for the same amount of carried passengers. Moreover, the signalling systems used in rail transport have evolved to become increasingly efficient. In particular, systems based on the ERTMS/ETCS (European Rail Traffic Management System/European Train Control System) are being developed recently because they guarantee interoperability at the European level, as well as considerably improve the performance of the rail systems. In this context, this paper analyses the use of the HD-ERTMS (i.e., High-Density ERTMS), normally applied in the case of railway nodes (as, for instance, complex stations) of double-track lines, in the case of single-track railway lines. Preliminary results have shown that the HD-ERTMS allows forwarding consecutive platoons of rail convoys in the same direction thus increasing the line capacity by up to 60%.
Keywords: signalling system, HD-ERTMS, railway system, single-track line, user waiting time, station platform.
Proceedings of the 12th International Conference Environmental Engineering (ICEE 2023), Vilnius, Lithuania, April 2023, 2023
Some events (as, for instance, a bridge collapse, an underpass closure or a road maintenance inte... more Some events (as, for instance, a bridge collapse, an underpass closure or a road maintenance intervention) may generate the total or partial unavailability of some elements of urban road networks. Hence, some users have to redirect their paths generating an increase in congestion on the remaining part of the network. In this context, this paper proposes the design of additional public transport services to increase the resilience of road urban networks by affecting the user modal choices to reduce road flows and bring congestion levels as close as possible to the initial equilibrium conditions. Finally, to verify the usefulness and feasibility of the proposed methodology, it has been applied in the case of the road network of Fuorigrotta, a district of the city of Naples, in southern Italy.
Keywords: urban transport management, public transport services, network resilience, multimodal network design, user equilibrium.
IEEE Transactions on Transportation Electrification 9(1), pp. 1554-1563, 2023
The operators of the railway industry (i.e., Traction System and Railway System Operators) are cu... more The operators of the railway industry (i.e., Traction System and Railway System Operators) are currently involved in a major process of energy transition. Aimed at improving both environmental sustainability and energy efficiency, technological infrastructures are being updated and new operating solutions studied. Moreover, the business opportunities offered by the new rail market are forcing operators to search for power quality solutions. In this paper, an efficiency strategy is proposed for optimally moving a fleet of trains while taking power quality indices into account. A method to relate the traction power requirements to the electrical variables of the railway infrastructure is formulated in terms of the power flow approach. Our numerical simulations focus on the real case of the Metro Line 1 in the southern Italian city of Naples. The energy problem of moving the trains on the track is solved by including a set of constraints at the point of common interaction between railway market operators. Specifically, repetitive train starts and their speed profiles are optimally managed in terms of power requirements at traction power substations by using power quality constraints. This strategy allows improvements in energy efficiency without compromising the quality of the railway service.
Keywords: Optimal approach, power constraint, power flow, railway industry market, traction power system, train requirements.
Proceedings of the 22nd IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2022) and 6th Industrial and Commercial Power Systems Europe (I&CPS 2022), Prague, Czech Republic, June-July 2022, 2022
The accessibility level of urban areas depends on the attractiveness of the zone and its reachabi... more The accessibility level of urban areas depends on the attractiveness of the zone and its reachability degree. The former is affected by settled activities; the latter depends on features of the supply system. From a sustainable perspective, one of the key strategies is promoting the use of active modes and micro-mobility options. In this context, the paper aims to investigate the variations in student accessibility (i.e., passive accessibility) due to the adoption of a micro-mobility solution. To show the feasibility of the proposed approach, it has been applied in the case of university plexuses in the Fuorigrotta district (Naples, Italy). Simulation results confirm that such solutions increase the accessibility level and show that they are preferred by users as first/last mile options, as well as for replacing pedestrian trips. Moreover, the provided outcome reveals the effectiveness of the proposed methodology as a Decision Support System (DSS) for helping micro-mobility operators to design service features.
Keywords: accessibility, public transport, micro-mobility solutions, student mobility
Sustainable transport frameworks are gaining attention within national and international transpor... more Sustainable transport frameworks are gaining attention within national and international transportation policies, given the key role that decarbonisation plays in making urban environments people-friendly. Within this context, several shared services and micro-mobility options are being developed, especially as first/last mile facilities, further increasing public transport coverage levels. We present an overview of the environmental impacts of different transport modes and compare them from different perspectives, namely, CO2 emission levels, total costs (also including the user generalised cost) and service life of vehicles involved. The proposed methodology is applied to an urban context, using real trip data and showing the main findings under real conditions.
Keywords: sustainable transport modes; micro-mobility options; CO2 emissions; user generalised cost; vehicle service life.
Lectures Notes in Networks and Systems 451, pp. 637-646, 2022
Due to the global pandemic we are experiencing, our lives and social behaviours in urban contexts... more Due to the global pandemic we are experiencing, our lives and social behaviours in urban contexts are deeply changed. Many regulations and rules have been and still are enacted by the world’s governments to minimise the level of risk to which the population is exposed. The majority of them aims at ensuring people social distancing and, in this context, the public transport sector plays a crucial role. Indeed, guaranteeing social distancing on buses or trains, while maintaining good service quality at the same time, represents a very challenging goal. Within this framework, the paper presents a methodology for optimising rail service operations thus satisfying mobility demand while complying with the maximum occupation coefficients allowed by current regulations. In order to show the goodness of the proposed method, it has been applied in the case of a real regional rail line in the south of Italy.
Keywords: Covid-19 pandemic, Social distancing, Rail service capacity, Occupation coefficients
Proceedings of the 2021 IEEE Vehicle Power and Propulsion Conference (IEEE VPPC 2021), Gijon, Spain, October 2021, 2021
Due to the liberalization of the railway sector, Railway System Operators (RSOs) are involved in ... more Due to the liberalization of the railway sector, Railway System Operators (RSOs) are involved in the renewal of railway systems in terms of both technological and managing improvements. They are evaluating how new strategies can improve energy efficiency and operating sustainability. This paper proposes the optimal management of a fleet of metro trains in terms of power key performance indicator (KPI). To control the regularity of the railway service assuming a constant Headway value, there were examined how the optimal assignment of the Layover time between the two terminal stops can be managed concerning the maximum power requirements at the Traction Power Substations (TPSs). The numerical application focused on the traction power system of Metro Line 1 of Naples (Italy). The results highlighted the evaluation of the power peaks required to the distribution grid as a function of the Layover time assignment.
Keywords: traction power system, fleet of trains, coordinated motion, layover time, optimal model.
Proceedings of the 21st IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2021) and 5th Industrial and Commercial Power Systems Europe (I&CPS 2021), Bari, Italy, September 2021, 2021
Our cities are becoming increasingly smart thanks to information and communication technologies, ... more Our cities are becoming increasingly smart thanks to information and communication technologies, sustainable solutions for human activities and innovative mobility frameworks. In this context, one of the most promising approaches is relying on the Internet of Things (IoT) which allows objects of everyday life to become computing devices exchanging useful data. In particular, the paper proposes to adopt such technologies for monitoring railway systems, thus obtaining information concerning, on one hand, service performance and, on the other, travellers’ behaviour. A numerical application has been performed in a real rail context, thus pointing out the feasibility of the proposed methodology.
Journal of Advanced Transportation 2021, pp. 1-11, 2021
The use of Building Information Modelling (BIM) is becoming increasingly adopted worldwide to sup... more The use of Building Information Modelling (BIM) is becoming increasingly adopted worldwide to support the creation and management of digital environments in which physical and functional features of a facility are modelled. Due to its characteristic flexibility and interoperability, it rapidly extends beyond the boundaries of applications for which it was originally conceived, thus being implemented in other contexts such as the infrastructure sector. Indeed, during each phase of the construction process for building a linear infrastructure, suitable design of a traffic control plan to optimising traffic flows proves crucial, both for drivers and builders. In this context, there arises the need to perform a comprehensive analysis, combining infrastructure design and building issues with transportation theory principles. For this purpose, the paper proposes a comparative analysis of two different approaches relying on BIM-based tools, namely integrated (i.e. BIM environments with an in-built module for transport simulation tasks) and an interfaceable solution (i.e. BIM environments offering a customised interface for external mobility simulation software). Specifically, after an overview of the issues involved, the two solutions analysed are customised according to the software packages adopted and a numerical application is carried out. The goal of the paper is to perform a preliminary analysis on the potential of such frameworks by means of comparative evaluation aimed at identifying pros and cons of the two approaches, as well as the best field of application, according to the effort required of the designer, the degree of flexibility offered and the target pursued.
Lectures Notes in Networks and Systems 227, pp. 667-676, 2021
Smart and sustainable mobility systems are crucial elements for tomorrow’s cities, whose faciliti... more Smart and sustainable mobility systems are crucial elements for tomorrow’s cities, whose facilities will be increasingly connected automated and environmentally friendly. Therefore, many strategies based on alternatively-powered vehicles, shared transport modes and micro-mobility solutions are being developed. However, the promotion of traditional public transport solutions still remains a key factor. Therefore, increasing their attractiveness, thus positively influencing the modal split, turns out to be an important goal to be achieved. In this context, we proposed a methodology, based on the use of Automatic Vehicle Location (AVL) data, for improving transit service performance. Finally, in order to show the feasibility of the proposed approach, it has been applied to a real bus line operating in the south of Italy.
Keywords: public transport systems, AVL data, service regularity.
Public transport systems can be characterised by a schedule-based or a frequency-based framework ... more Public transport systems can be characterised by a schedule-based or a frequency-based framework according to the kind of service to be operated. In the former case, specific departure and arrival times are set for each run and disclosed to the users; in the latter, instead, it is necessary to maintain a certain headway between two successive runs, rather than a specific timetable structure. This paper focuses on modelling frequency-based systems, which can be described by means of the so-called Merry-Go-Round (MGR) paradigm. The paradigm is first discussed and the related an-alytical formulation is presented; the role of the terminal station layout is then investigated within this framework. Finally, in order to show the effectiveness of the proposed formulation, it was implemented in the case of a real-scale metro line.
IEEE Transactions on Vehicular Technology 69(12), pp. 14131-14140, 2020
Electrified railway systems are the current focus of energy efficiency studies due to the increas... more Electrified railway systems are the current focus of energy efficiency studies due to the increasing constraints of environmental sustainability policies. Railway System Operators (RSOs), also encouraged by market deregulation, are thus examining how to update infrastructures and vehicles and/or apply new operating strategies. Given the intrinsic relation between railway systems and their primary feeding grid, each measure applied to a railway system impacts directly on the power grid which supplies the system. Against this background, this paper aims to ascertain the impact of an energy efficiency strategy applied by the RSO system on its primary grid. The energy-efficient strategy is identified as to preserve timetable stability and service quality in a passenger-oriented perspective. Moreover, a method to model the interaction between the systems in terms of power flow exchanges is proposed. The model is used to verify how an eco-driving technique applied to a metro system affects the state variables of the distribution grid. In particular, the primary grid, the traction power substations and the railway system are modelled according to real data. The case study is the Metro Line 1 operating in the city of Naples (Italy). The numerical simulations are carried out with a two-step procedure: first, the power requirements of the rolling stock as a function of the imposed operating service are calculated by OPENTRACK® software; the state variables of the distribution grid are then evaluated by means of the power flow approach.
Keywords: Energy efficiency, power grids, rail transportation, voltage measurement.
Proceedings of the 2020 IEEE Vehicle Power and Propulsion Conference (IEEE VPPC 2020), Gijon, Spain, November-December 2020, 2020
Today, electrified railway systems are involved in renewal processes, which address vehicles, way... more Today, electrified railway systems are involved in renewal processes, which address vehicles, wayside infrastructure and management of fleet of rolling stocks. Railway System Operators (RSOs) test how novel and innovative strategies impact of their own systems in order to reach energy efficiency targets. Due to the intrinsic interaction between the railway traction system and its primary grid, the feasibility of each innovative strategy has to be evaluated in terms of energy and power not only on the railway traction system, but also on its feeding grid. In the actual context forced by the constraint of Covid-19 virus, one of the more relevant strategies applied to urban railway systems is to operate the railway traction system with reduced values of headway. This strategy, which forces repetitive starts, in some cases contemporaneous, of rolling stocks, can produce severe voltage drops on the primary distribution grid. This paper proposes of examining the motion of a fleet of metro trains on a traction system fed by a MV distribution grid of reduced short circuit value. The numerical results point out how constraints imposed by the distribution grid at the Traction Power Substations can influence the control of moving the fleet of rolling stocks on the track.
Keywords: traction system, train motion, electrical power, distribution grid, voltage drop.
We propose a model for optimising driving speed profiles on metro lines to reduce traction energy... more We propose a model for optimising driving speed profiles on metro lines to reduce traction energy consumption. The model optimises the cruising speed to be maintained on each section between two stations; the functions that link the cruising speed to the travel time on the section and the corresponding energy consumption are built using microscopic railway simulation software. In addition to formulating an optimisation model and its resolution through a gradient algorithm, the problem is also solved by using a simulation model and the corresponding optimisation module, with which stochastic factors may be included in the problem. The results are promising and show that traction energy savings of over 25% compared to non-optimised operations may be achieved.
Keywords: energy-saving; railway sector; metro lines; driving speed profiles; simulation.
In this paper, we propose a generalisation of the Method of Successive Averages (MSA) for solving... more In this paper, we propose a generalisation of the Method of Successive Averages (MSA) for solving traffic assignment problems. The generalisation consists in proposing a different step sequence within the general MSA framework to reduce computing times. The proposed step sequence is based on the modification of the classic 1/k sequence for improving the convergence speed of the algorithm. The reduction in computing times is useful if the assignment problems are subroutines of algorithms for solving Network Design Problems—such algorithms require estimation of the equilibrium traffic flows at each iteration, hence, many thousands of times for real-scale cases. The proposed algorithm is tested with different parameter values and compared with the classic MSA algorithm on a small and on two real-scale networks. A test inside a Network Design Problem is also reported. Numerical results show that the proposed algorithm outperforms the classic MSA with reductions in computing times, reaching up to 79%. Finally, the theoretical properties are studied for stating the convergence of the proposed algorithm.
The sustainable design of public transport services is a crucial issue that may affect the econom... more The sustainable design of public transport services is a crucial issue that may affect the economy of local areas and the social inclusion of their inhabitants. Indeed, transport accessibility of households, businesses, and retail activities is one of the main drivers that influence location choices and sustainable development and where the public transport services may play a key (positive) role. Furthermore, the economic crisis of the 2009 and the current ones caused by the COVID-19 pandemic has further limited the funds available for public services, including the transport sector. In this critical context, sound design of public transport services assumes great importance, especially in light of financial constraints. Starting from these considerations, the aim of this paper has been to propose an innovative methodology for designing public transport services based on a rational decision-making process with stakeholder engagement, aiming in performingto perform a sustainable development perspective. The proposed methodology combines technical aspects, social and political issues, equity perspectives, and it is aimed in obtaining a design solution that can be accepted by the whole community. The proposed theoretical design methodology has also been also applied to a case study in order to verify its applicability to a real context, consisting inof the design of the public transport plan of the province of Foggia in southern Italy. Applications results show that the sustainable design scenario is not only the best ones from a technical point of view, but also participated, equitable, and approved by both policy-makerspolicymakers and stakeholders.
Keywords: local public transport; network and services design; public engagement; equitable resource allocation; sustainable mobility; transport quality.
Proceedings of the 20th IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2020) and 4th Industrial and Commercial Power Systems Europe (I&CPS 2020), Madrid, Spain, June 2020, 2020
In this paper, we propose a model for the optimisation of driving speed profiles on metro lines, ... more In this paper, we propose a model for the optimisation of driving speed profiles on metro lines, to reduce overall energy consumption. The proposed model optimises the maximum speed to be maintained on each section between two stations; the functions that link this maximum speed to the travel time on the section and the corresponding energy consumption are built using a microscopic railway simulation software. The results obtained are promising and show how it is possible to achieve traction energy savings of over 25% compared to non-optimised operations.
Keywords: energy-saving, railway sector, metro lines, driving speed profiles.
Proceedings of the 20th IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2020) and 4th Industrial and Commercial Power Systems Europe (I&CPS 2020), Madrid, Spain, June 2020, 2020
Public transport may represent a useful tool to increase the sustainability of areas, especially ... more Public transport may represent a useful tool to increase the sustainability of areas, especially in urban and suburban contexts. The attractiveness of a transport system, especially in the case of buses, is closely linked to its reliability which depends in turn on the adoption of adequate planning and design methodologies. Currently, although the dwell time (i.e. the time spent by a vehicle at a bus stop for boarding and alighting passengers) may represent a relevant rate of the total travel time, it generally is adopted as constant and prefixed. In this context, this paper aims to identify an analytical formulation to determine at each bus stop the corresponding dwell time to increase the reliability of the planned service. Numerical results have shown the correctness of the proposed approach.
Keywords: mass-transit service, operational parameters, bus fleet, dwell time.
International Journal of Computational Science and Engineering 26(5), pp. 505-512, 2023
After the separation of rail infrastructure managers from rail service operators occurred within ... more After the separation of rail infrastructure managers from rail service operators occurred within the European Union in 1991, the necessity of defining an access charge framework for ensuring non-discriminatory access to the rail market arose. Basically, it has to guarantee an economic balance for infrastructure manager accounts. Currently, in the Italian context, access charge schemes neglect the actual energy-consumption of rail operators and related costs of energy traction for infrastructure managers. Therefore, we propose a methodology, integrating cloud-based tasks and simulation tools, for including such an aspect within the infrastructure toll, thus making the system more sustainable. Finally, to show the feasibility of the proposed approach, it has been applied to an Italian real rail context, i.e. the Rome-Naples high-speed railway line. Results have shown that customising the tool access charges, by considering the power supply required, may generate a virtuous loop with an increase in energy-efficiency of rail systems.
Proceedings of the 6th International Conference of Contemporary Affairs in Architecture and Urbanism (ICCAUA 2023), Istanbul, Türkiye, June 2023, 2023
Smart and green mobility systems are key factors for the sustainability of our cities which are e... more Smart and green mobility systems are key factors for the sustainability of our cities which are experiencing increasingly growing density conditions. The goal is to make public and sharing transport systems more attractive than private vehicles, thus reducing congestion levels as well as air and noise pollution in favour of the quality of life in our urban and suburban areas. In this context, the proposed paper presents a simulation-based methodology for increasing the efficiency level of railway operations, through the implementation of virtual coupling systems, intending to lead the modal split towards a more sustainable scenario. To show the feasibility of the proposed approach, it has been applied in the case of a real regional rail line. Results confirm the benefits of the adoption of such systems on the attractiveness levels by showing an increase in carrying capacity with a related reduction in user waiting times.
Proceedings of the 23rd IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2023) and 7th Industrial and Commercial Power Systems Europe (I&CPS 2023), Madrid, Spain, June 2023, 2023
Rail transport is one of the most sustainable transportation systems since it requires the use of... more Rail transport is one of the most sustainable transportation systems since it requires the use of smaller unitary energy resources for the same amount of carried passengers. Moreover, the signalling systems used in rail transport have evolved to become increasingly efficient. In particular, systems based on the ERTMS/ETCS (European Rail Traffic Management System/European Train Control System) are being developed recently because they guarantee interoperability at the European level, as well as considerably improve the performance of the rail systems. In this context, this paper analyses the use of the HD-ERTMS (i.e., High-Density ERTMS), normally applied in the case of railway nodes (as, for instance, complex stations) of double-track lines, in the case of single-track railway lines. Preliminary results have shown that the HD-ERTMS allows forwarding consecutive platoons of rail convoys in the same direction thus increasing the line capacity by up to 60%.
Keywords: signalling system, HD-ERTMS, railway system, single-track line, user waiting time, station platform.
Proceedings of the 12th International Conference Environmental Engineering (ICEE 2023), Vilnius, Lithuania, April 2023, 2023
Some events (as, for instance, a bridge collapse, an underpass closure or a road maintenance inte... more Some events (as, for instance, a bridge collapse, an underpass closure or a road maintenance intervention) may generate the total or partial unavailability of some elements of urban road networks. Hence, some users have to redirect their paths generating an increase in congestion on the remaining part of the network. In this context, this paper proposes the design of additional public transport services to increase the resilience of road urban networks by affecting the user modal choices to reduce road flows and bring congestion levels as close as possible to the initial equilibrium conditions. Finally, to verify the usefulness and feasibility of the proposed methodology, it has been applied in the case of the road network of Fuorigrotta, a district of the city of Naples, in southern Italy.
Keywords: urban transport management, public transport services, network resilience, multimodal network design, user equilibrium.
IEEE Transactions on Transportation Electrification 9(1), pp. 1554-1563, 2023
The operators of the railway industry (i.e., Traction System and Railway System Operators) are cu... more The operators of the railway industry (i.e., Traction System and Railway System Operators) are currently involved in a major process of energy transition. Aimed at improving both environmental sustainability and energy efficiency, technological infrastructures are being updated and new operating solutions studied. Moreover, the business opportunities offered by the new rail market are forcing operators to search for power quality solutions. In this paper, an efficiency strategy is proposed for optimally moving a fleet of trains while taking power quality indices into account. A method to relate the traction power requirements to the electrical variables of the railway infrastructure is formulated in terms of the power flow approach. Our numerical simulations focus on the real case of the Metro Line 1 in the southern Italian city of Naples. The energy problem of moving the trains on the track is solved by including a set of constraints at the point of common interaction between railway market operators. Specifically, repetitive train starts and their speed profiles are optimally managed in terms of power requirements at traction power substations by using power quality constraints. This strategy allows improvements in energy efficiency without compromising the quality of the railway service.
Keywords: Optimal approach, power constraint, power flow, railway industry market, traction power system, train requirements.
Proceedings of the 22nd IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2022) and 6th Industrial and Commercial Power Systems Europe (I&CPS 2022), Prague, Czech Republic, June-July 2022, 2022
The accessibility level of urban areas depends on the attractiveness of the zone and its reachabi... more The accessibility level of urban areas depends on the attractiveness of the zone and its reachability degree. The former is affected by settled activities; the latter depends on features of the supply system. From a sustainable perspective, one of the key strategies is promoting the use of active modes and micro-mobility options. In this context, the paper aims to investigate the variations in student accessibility (i.e., passive accessibility) due to the adoption of a micro-mobility solution. To show the feasibility of the proposed approach, it has been applied in the case of university plexuses in the Fuorigrotta district (Naples, Italy). Simulation results confirm that such solutions increase the accessibility level and show that they are preferred by users as first/last mile options, as well as for replacing pedestrian trips. Moreover, the provided outcome reveals the effectiveness of the proposed methodology as a Decision Support System (DSS) for helping micro-mobility operators to design service features.
Keywords: accessibility, public transport, micro-mobility solutions, student mobility
Sustainable transport frameworks are gaining attention within national and international transpor... more Sustainable transport frameworks are gaining attention within national and international transportation policies, given the key role that decarbonisation plays in making urban environments people-friendly. Within this context, several shared services and micro-mobility options are being developed, especially as first/last mile facilities, further increasing public transport coverage levels. We present an overview of the environmental impacts of different transport modes and compare them from different perspectives, namely, CO2 emission levels, total costs (also including the user generalised cost) and service life of vehicles involved. The proposed methodology is applied to an urban context, using real trip data and showing the main findings under real conditions.
Keywords: sustainable transport modes; micro-mobility options; CO2 emissions; user generalised cost; vehicle service life.
Lectures Notes in Networks and Systems 451, pp. 637-646, 2022
Due to the global pandemic we are experiencing, our lives and social behaviours in urban contexts... more Due to the global pandemic we are experiencing, our lives and social behaviours in urban contexts are deeply changed. Many regulations and rules have been and still are enacted by the world’s governments to minimise the level of risk to which the population is exposed. The majority of them aims at ensuring people social distancing and, in this context, the public transport sector plays a crucial role. Indeed, guaranteeing social distancing on buses or trains, while maintaining good service quality at the same time, represents a very challenging goal. Within this framework, the paper presents a methodology for optimising rail service operations thus satisfying mobility demand while complying with the maximum occupation coefficients allowed by current regulations. In order to show the goodness of the proposed method, it has been applied in the case of a real regional rail line in the south of Italy.
Keywords: Covid-19 pandemic, Social distancing, Rail service capacity, Occupation coefficients
Proceedings of the 2021 IEEE Vehicle Power and Propulsion Conference (IEEE VPPC 2021), Gijon, Spain, October 2021, 2021
Due to the liberalization of the railway sector, Railway System Operators (RSOs) are involved in ... more Due to the liberalization of the railway sector, Railway System Operators (RSOs) are involved in the renewal of railway systems in terms of both technological and managing improvements. They are evaluating how new strategies can improve energy efficiency and operating sustainability. This paper proposes the optimal management of a fleet of metro trains in terms of power key performance indicator (KPI). To control the regularity of the railway service assuming a constant Headway value, there were examined how the optimal assignment of the Layover time between the two terminal stops can be managed concerning the maximum power requirements at the Traction Power Substations (TPSs). The numerical application focused on the traction power system of Metro Line 1 of Naples (Italy). The results highlighted the evaluation of the power peaks required to the distribution grid as a function of the Layover time assignment.
Keywords: traction power system, fleet of trains, coordinated motion, layover time, optimal model.
Proceedings of the 21st IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2021) and 5th Industrial and Commercial Power Systems Europe (I&CPS 2021), Bari, Italy, September 2021, 2021
Our cities are becoming increasingly smart thanks to information and communication technologies, ... more Our cities are becoming increasingly smart thanks to information and communication technologies, sustainable solutions for human activities and innovative mobility frameworks. In this context, one of the most promising approaches is relying on the Internet of Things (IoT) which allows objects of everyday life to become computing devices exchanging useful data. In particular, the paper proposes to adopt such technologies for monitoring railway systems, thus obtaining information concerning, on one hand, service performance and, on the other, travellers’ behaviour. A numerical application has been performed in a real rail context, thus pointing out the feasibility of the proposed methodology.
Journal of Advanced Transportation 2021, pp. 1-11, 2021
The use of Building Information Modelling (BIM) is becoming increasingly adopted worldwide to sup... more The use of Building Information Modelling (BIM) is becoming increasingly adopted worldwide to support the creation and management of digital environments in which physical and functional features of a facility are modelled. Due to its characteristic flexibility and interoperability, it rapidly extends beyond the boundaries of applications for which it was originally conceived, thus being implemented in other contexts such as the infrastructure sector. Indeed, during each phase of the construction process for building a linear infrastructure, suitable design of a traffic control plan to optimising traffic flows proves crucial, both for drivers and builders. In this context, there arises the need to perform a comprehensive analysis, combining infrastructure design and building issues with transportation theory principles. For this purpose, the paper proposes a comparative analysis of two different approaches relying on BIM-based tools, namely integrated (i.e. BIM environments with an in-built module for transport simulation tasks) and an interfaceable solution (i.e. BIM environments offering a customised interface for external mobility simulation software). Specifically, after an overview of the issues involved, the two solutions analysed are customised according to the software packages adopted and a numerical application is carried out. The goal of the paper is to perform a preliminary analysis on the potential of such frameworks by means of comparative evaluation aimed at identifying pros and cons of the two approaches, as well as the best field of application, according to the effort required of the designer, the degree of flexibility offered and the target pursued.
Lectures Notes in Networks and Systems 227, pp. 667-676, 2021
Smart and sustainable mobility systems are crucial elements for tomorrow’s cities, whose faciliti... more Smart and sustainable mobility systems are crucial elements for tomorrow’s cities, whose facilities will be increasingly connected automated and environmentally friendly. Therefore, many strategies based on alternatively-powered vehicles, shared transport modes and micro-mobility solutions are being developed. However, the promotion of traditional public transport solutions still remains a key factor. Therefore, increasing their attractiveness, thus positively influencing the modal split, turns out to be an important goal to be achieved. In this context, we proposed a methodology, based on the use of Automatic Vehicle Location (AVL) data, for improving transit service performance. Finally, in order to show the feasibility of the proposed approach, it has been applied to a real bus line operating in the south of Italy.
Keywords: public transport systems, AVL data, service regularity.
Public transport systems can be characterised by a schedule-based or a frequency-based framework ... more Public transport systems can be characterised by a schedule-based or a frequency-based framework according to the kind of service to be operated. In the former case, specific departure and arrival times are set for each run and disclosed to the users; in the latter, instead, it is necessary to maintain a certain headway between two successive runs, rather than a specific timetable structure. This paper focuses on modelling frequency-based systems, which can be described by means of the so-called Merry-Go-Round (MGR) paradigm. The paradigm is first discussed and the related an-alytical formulation is presented; the role of the terminal station layout is then investigated within this framework. Finally, in order to show the effectiveness of the proposed formulation, it was implemented in the case of a real-scale metro line.
IEEE Transactions on Vehicular Technology 69(12), pp. 14131-14140, 2020
Electrified railway systems are the current focus of energy efficiency studies due to the increas... more Electrified railway systems are the current focus of energy efficiency studies due to the increasing constraints of environmental sustainability policies. Railway System Operators (RSOs), also encouraged by market deregulation, are thus examining how to update infrastructures and vehicles and/or apply new operating strategies. Given the intrinsic relation between railway systems and their primary feeding grid, each measure applied to a railway system impacts directly on the power grid which supplies the system. Against this background, this paper aims to ascertain the impact of an energy efficiency strategy applied by the RSO system on its primary grid. The energy-efficient strategy is identified as to preserve timetable stability and service quality in a passenger-oriented perspective. Moreover, a method to model the interaction between the systems in terms of power flow exchanges is proposed. The model is used to verify how an eco-driving technique applied to a metro system affects the state variables of the distribution grid. In particular, the primary grid, the traction power substations and the railway system are modelled according to real data. The case study is the Metro Line 1 operating in the city of Naples (Italy). The numerical simulations are carried out with a two-step procedure: first, the power requirements of the rolling stock as a function of the imposed operating service are calculated by OPENTRACK® software; the state variables of the distribution grid are then evaluated by means of the power flow approach.
Keywords: Energy efficiency, power grids, rail transportation, voltage measurement.
Proceedings of the 2020 IEEE Vehicle Power and Propulsion Conference (IEEE VPPC 2020), Gijon, Spain, November-December 2020, 2020
Today, electrified railway systems are involved in renewal processes, which address vehicles, way... more Today, electrified railway systems are involved in renewal processes, which address vehicles, wayside infrastructure and management of fleet of rolling stocks. Railway System Operators (RSOs) test how novel and innovative strategies impact of their own systems in order to reach energy efficiency targets. Due to the intrinsic interaction between the railway traction system and its primary grid, the feasibility of each innovative strategy has to be evaluated in terms of energy and power not only on the railway traction system, but also on its feeding grid. In the actual context forced by the constraint of Covid-19 virus, one of the more relevant strategies applied to urban railway systems is to operate the railway traction system with reduced values of headway. This strategy, which forces repetitive starts, in some cases contemporaneous, of rolling stocks, can produce severe voltage drops on the primary distribution grid. This paper proposes of examining the motion of a fleet of metro trains on a traction system fed by a MV distribution grid of reduced short circuit value. The numerical results point out how constraints imposed by the distribution grid at the Traction Power Substations can influence the control of moving the fleet of rolling stocks on the track.
Keywords: traction system, train motion, electrical power, distribution grid, voltage drop.
We propose a model for optimising driving speed profiles on metro lines to reduce traction energy... more We propose a model for optimising driving speed profiles on metro lines to reduce traction energy consumption. The model optimises the cruising speed to be maintained on each section between two stations; the functions that link the cruising speed to the travel time on the section and the corresponding energy consumption are built using microscopic railway simulation software. In addition to formulating an optimisation model and its resolution through a gradient algorithm, the problem is also solved by using a simulation model and the corresponding optimisation module, with which stochastic factors may be included in the problem. The results are promising and show that traction energy savings of over 25% compared to non-optimised operations may be achieved.
Keywords: energy-saving; railway sector; metro lines; driving speed profiles; simulation.
In this paper, we propose a generalisation of the Method of Successive Averages (MSA) for solving... more In this paper, we propose a generalisation of the Method of Successive Averages (MSA) for solving traffic assignment problems. The generalisation consists in proposing a different step sequence within the general MSA framework to reduce computing times. The proposed step sequence is based on the modification of the classic 1/k sequence for improving the convergence speed of the algorithm. The reduction in computing times is useful if the assignment problems are subroutines of algorithms for solving Network Design Problems—such algorithms require estimation of the equilibrium traffic flows at each iteration, hence, many thousands of times for real-scale cases. The proposed algorithm is tested with different parameter values and compared with the classic MSA algorithm on a small and on two real-scale networks. A test inside a Network Design Problem is also reported. Numerical results show that the proposed algorithm outperforms the classic MSA with reductions in computing times, reaching up to 79%. Finally, the theoretical properties are studied for stating the convergence of the proposed algorithm.
The sustainable design of public transport services is a crucial issue that may affect the econom... more The sustainable design of public transport services is a crucial issue that may affect the economy of local areas and the social inclusion of their inhabitants. Indeed, transport accessibility of households, businesses, and retail activities is one of the main drivers that influence location choices and sustainable development and where the public transport services may play a key (positive) role. Furthermore, the economic crisis of the 2009 and the current ones caused by the COVID-19 pandemic has further limited the funds available for public services, including the transport sector. In this critical context, sound design of public transport services assumes great importance, especially in light of financial constraints. Starting from these considerations, the aim of this paper has been to propose an innovative methodology for designing public transport services based on a rational decision-making process with stakeholder engagement, aiming in performingto perform a sustainable development perspective. The proposed methodology combines technical aspects, social and political issues, equity perspectives, and it is aimed in obtaining a design solution that can be accepted by the whole community. The proposed theoretical design methodology has also been also applied to a case study in order to verify its applicability to a real context, consisting inof the design of the public transport plan of the province of Foggia in southern Italy. Applications results show that the sustainable design scenario is not only the best ones from a technical point of view, but also participated, equitable, and approved by both policy-makerspolicymakers and stakeholders.
Keywords: local public transport; network and services design; public engagement; equitable resource allocation; sustainable mobility; transport quality.
Proceedings of the 20th IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2020) and 4th Industrial and Commercial Power Systems Europe (I&CPS 2020), Madrid, Spain, June 2020, 2020
In this paper, we propose a model for the optimisation of driving speed profiles on metro lines, ... more In this paper, we propose a model for the optimisation of driving speed profiles on metro lines, to reduce overall energy consumption. The proposed model optimises the maximum speed to be maintained on each section between two stations; the functions that link this maximum speed to the travel time on the section and the corresponding energy consumption are built using a microscopic railway simulation software. The results obtained are promising and show how it is possible to achieve traction energy savings of over 25% compared to non-optimised operations.
Keywords: energy-saving, railway sector, metro lines, driving speed profiles.
Proceedings of the 20th IEEE International Conference on Environment and Electrical Engineering (IEEE EEEIC 2020) and 4th Industrial and Commercial Power Systems Europe (I&CPS 2020), Madrid, Spain, June 2020, 2020
Public transport may represent a useful tool to increase the sustainability of areas, especially ... more Public transport may represent a useful tool to increase the sustainability of areas, especially in urban and suburban contexts. The attractiveness of a transport system, especially in the case of buses, is closely linked to its reliability which depends in turn on the adoption of adequate planning and design methodologies. Currently, although the dwell time (i.e. the time spent by a vehicle at a bus stop for boarding and alighting passengers) may represent a relevant rate of the total travel time, it generally is adopted as constant and prefixed. In this context, this paper aims to identify an analytical formulation to determine at each bus stop the corresponding dwell time to increase the reliability of the planned service. Numerical results have shown the correctness of the proposed approach.
Keywords: mass-transit service, operational parameters, bus fleet, dwell time.
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Papers by Luca D'Acierno
Keywords: Cloud-based applications; rail infrastructure access charges; environmental component; energy-saving policies.
Keywords: Sustainable mobility; traffic engineering; rail operations; virtual coupling; carrying capacity.
Keywords: signalling system, HD-ERTMS, railway system, single-track line, user waiting time, station platform.
Keywords: urban transport management, public transport services, network resilience, multimodal network design, user equilibrium.
Keywords: Optimal approach, power constraint, power flow, railway industry market, traction power system, train requirements.
Keywords: accessibility, public transport, micro-mobility solutions, student mobility
Keywords: sustainable transport modes; micro-mobility options; CO2 emissions; user generalised cost; vehicle service life.
Keywords: Covid-19 pandemic, Social distancing, Rail service capacity, Occupation coefficients
Keywords: traction power system, fleet of trains, coordinated motion, layover time, optimal model.
Keywords: BIM-based tools, linear infrastructure, traffic flow simulation, integrated solution, interfaceable solution.
Keywords: public transport systems, AVL data, service regularity.
Keywords: railway transport; frequency-based systems; Merry-Go-Round paradigm; analytical formalisation; terminus layout.
Keywords: Energy efficiency, power grids, rail transportation, voltage measurement.
Keywords: traction system, train motion, electrical power, distribution grid, voltage drop.
Keywords: energy-saving; railway sector; metro lines; driving speed profiles; simulation.
Keywords: traffic assignment; MSA algorithm; fixed-point problems; network design.
Keywords: local public transport; network and services design; public engagement; equitable resource allocation; sustainable mobility; transport quality.
non-optimised operations.
Keywords: energy-saving, railway sector, metro lines, driving speed profiles.
Keywords: mass-transit service, operational parameters, bus fleet, dwell time.
Keywords: Cloud-based applications; rail infrastructure access charges; environmental component; energy-saving policies.
Keywords: Sustainable mobility; traffic engineering; rail operations; virtual coupling; carrying capacity.
Keywords: signalling system, HD-ERTMS, railway system, single-track line, user waiting time, station platform.
Keywords: urban transport management, public transport services, network resilience, multimodal network design, user equilibrium.
Keywords: Optimal approach, power constraint, power flow, railway industry market, traction power system, train requirements.
Keywords: accessibility, public transport, micro-mobility solutions, student mobility
Keywords: sustainable transport modes; micro-mobility options; CO2 emissions; user generalised cost; vehicle service life.
Keywords: Covid-19 pandemic, Social distancing, Rail service capacity, Occupation coefficients
Keywords: traction power system, fleet of trains, coordinated motion, layover time, optimal model.
Keywords: BIM-based tools, linear infrastructure, traffic flow simulation, integrated solution, interfaceable solution.
Keywords: public transport systems, AVL data, service regularity.
Keywords: railway transport; frequency-based systems; Merry-Go-Round paradigm; analytical formalisation; terminus layout.
Keywords: Energy efficiency, power grids, rail transportation, voltage measurement.
Keywords: traction system, train motion, electrical power, distribution grid, voltage drop.
Keywords: energy-saving; railway sector; metro lines; driving speed profiles; simulation.
Keywords: traffic assignment; MSA algorithm; fixed-point problems; network design.
Keywords: local public transport; network and services design; public engagement; equitable resource allocation; sustainable mobility; transport quality.
non-optimised operations.
Keywords: energy-saving, railway sector, metro lines, driving speed profiles.
Keywords: mass-transit service, operational parameters, bus fleet, dwell time.