1,720,962 research outputs found
Recovery time and propagation effects of passenger transport disruptions
Full text linkWe propose a method to evaluate public transport network vulnerability. We study the evolution of the passenger Volume Over Capacity (VOC) ratio throughout the network to measure the spatial and temporal extent of the impacts caused by an unplanned service segment disruption. The VOC ratio provides an indication of the on-board travel comfort, an important level-of-service indicator, as well as reflects the residual capacity for absorbing additional demand. Because of the dynamic nature of public transport systems, disturbances propagate through the network in both time and space. Our modelling approach is able to capture transit system dynamics and quantify the extent to which the network exhibits spillover effects. We apply the method to the case of the rapid public transport system of Stockholm Sweden We demonstrate how the changes in network saturation and the corresponding recovery time can be quantified.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
Aircraft turnaround and industrial actions: how ground handlers' strikes affect airport airside operational efficiency
No full textThe efficiency of airport turnaround operations has often been compromised by various disruptive events out of the airlines' control, such as strikes, which negatively influence the punctuality and regularity of operations. The purpose of this work is to determine the loss of airport operational performance provoked by ground handlers' industrial actions. A discrete-event simulation model of both aircraft landing-and-takeoff (LTO) cycles and turnaround operations has been built by using AnyLogic. If the number of ground handler's operators decreases, turnaround operations require more time to be performed, resulting in delayed departures and knock-on delays. For the case study of Lisbon “Humberto Delgado” airport, turnaround time increases more than linearly with respect to the decrease of staff resources in service. When the number of operators decreases under a certain threshold, turnaround lengthening cannot be absorbed by buffer times and departure delays propagate in cascade over the day. This threshold should call for emergency actions and contingency plans
Towards Green and Smart Ro–Ro Port Terminal Operations: A Comparative Analysis of ICE, BET and e-AGT Tractors
Full text linkThe decarbonization and automation of port operations are emerging as key strategies to enhance the sustainability and efficiency of maritime logistics. This study proposes a simulation-based framework to assess the operational and environmental impacts of transitioning from traditional Internal Combustion Engine (ICE) tractors to Battery Electric Tractors (BET) and Automated Electric Guided Tractors (e-AGT) in Roll-on/Roll-off (Ro-Ro) port terminal operations. The proposed framework is applied to simulate a full vessel turnaround at the Ro-Ro terminal of the Port of Ravenna (Italy). A set of Key Performance Indicators (KPIs) is defined to evaluate turnaround time, vehicle productivity, energy consumption and CO2 emissions across three scenarios. The results indicate that both BET and e-AGT configurations significantly reduce emissions compared to ICE, with reduc-tions up to 40%. However, the e-AGT scenario reveals operational drawbacks, including increased unloading time and reduced fleet availability due to charging constraints and routing limitations. These findings highlight the environmental potential of automation and electrification but also emphasize the need for integrated planning of fleet size, charging infrastructure and circulation specifications. The proposed framework provides a replicable decision-support tool for port authorities and logistics operators to evaluate alternative handling technologies under realistic conditions
A discrete event simulation model for inbound baggage handling
No full textInbound baggage handling represents a crucial process among airport terminal's activities as it affects directly airport performance and passengers' service quality perception. It is important to make the inbound process as efficient as possible and to explore solutions to enhance the performance of the system, thus reducing passengers' waiting time at baggage carousels. The aim of this paper is to present a detailed discrete event model of inbound baggage handling at a large regional Italian airport. The simulation model allows to fully understand the whole process and to identify bottlenecks and critical operations. The model is validated by comparing the simulation results with real data
Logistics facilities location choice modeling: Effects of environmental constraints
No full textThe selection of logistics facility locations is a critical decision that influences supply chain efficiency, cost structures and operational resilience. While previous studies have extensively examined the role of transport accessibility in location choices, the interplay between socio-demographic, transport-related and environmental constraints remain partially underexplored. This study addresses this gap by developing a conditional logit model to assess the impact of these factors on logistics facility location decisions, using the Emilia-Romagna region (Italy) as a case study. The model incorporates key determinants of location choice, including proximity to transport infrastructure (highways, freight terminals, rail stations), population density, environmental risks (flooding and seismic hazards) and land-use restrictions (protected natural areas). Results confirm that transport accessibility is the primary driver of logistics location choices and that socio-demographic factors, particularly
population, also influence location preferences. Conversely, environmental constraints exert a negative effect on site selection, reducing the likelihood of a location being chosen. These findings bring significant policy implications.
Investments in logistics-oriented transport infrastructure – such as enhanced highway connectivity, intermodal terminals and advanced congestion management systems – remains essential for strengthening regional logistics competitiveness. Moreover, implementing risk mitigation measures in location choice process analysis, including flood-resilient warehousing and seismic-resistant facilities, can enable firms to operate in moderate-risk areas without undermining operational resilience. Finally, integrated transport and land-use
planning that harmonizes industrial expansion with environmental sustainability, through initiatives like ecoindustria parks, can support the development of resilient and efficient logistics systems
Airport Passenger Arrival Process: Estimation of Earliness Arrival Functions
No full textAirport terminals are complex nodes where passengers are processed under limited capacity conditions. Congestion problems and delays are likely to occur, with negative impacts on customer satisfaction. To keep high quality levels, the knowledge of passengers' arrival patterns is a key factor. In this study, a methodology based on the use of Bar Coded Boarding Pass (BCBP) technologies has been proposed to estimate arrival rate functions for different types of passengers (Low Cost and Full Carrier passengers) and time of the day. The results obtained for a test case have been analysed and discussed
Airport Ground Access Reliability and Resilience of Transit Networks: A Case Study
No full textAirport ground access is one of the key determinants influencing air travellers' airport choice. The continuous growth of air travel demand and the consequent induced road congestion have encouraged the development of efficient transit systems approaching the airport, thus promoting a modal shift from individual cars to greener transport alternatives. In addition, transit systems must be resilient and reliable to air travellers, since the cost of missing a flight is high. In this paper, resilience aspects of transit systems accessing airport areas are discussed and some indexes have been set up to estimate the transit network resilience. Three different transit systems to get to a large regional Italian airport (Automated People Mover, Airport Shuttle Bus, Bus Line) are modelled and the system resilience has been estimated for each scenario by using the proposed indexes
A methodological framework to evaluate the impact of disruptions on airport turnaround operations: a case study
Full text linkThe efficiency and quality of airport airside operations are frequently compromised by various, unexpected
disruptive events such as bad weather conditions, lack of handling staff and/or resources, strikes, aircraft diversions
or technical failures, which may reduce airport airside operating capacity and affect the punctuality and
regularity of the operations. In particular, disruptive events could lead to a substantial deviation of aircraft
operations from the schedule, by causing the reduction of the system capacity and, thus, increasing congestion
and flight delays, which worsen the overall performance of the air transport system. In this paper, the effects of
unexpected events, particularly magnitude and duration, affecting airport airside operations are estimated
within a general framework based on an element-by-element approach, adopted for the detailed representation
and simulation of aircraft airside operations. The impacts generated by airport airside unexpected disruptions
are modelled by using a discrete-event simulation model, dealing with both aircraft landing-and-takeoff (LTO)
cycles and turnaround operations, developed and applied to the test case of a large regional airport
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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