Landside operations in air cargo terminals consist of many freight forwarders (FFWs) delivering and picking up cargo at the capacity-constrained loading docks at the airport's ground handlers' (GHs) facilities. To improve the operations of the terminal and take advantage of their geographical proximity a small set of FFWs can build a coalition to consolidate stochastically-arriving shipments and share truck fleet capacity while other FFWs continue bringing cargo to the terminal in a non-cooperative manner. Results from a detailed discrete-event simulation model of the cargo landside operations in Amsterdam Aiport showed that all operational policies had trade-offs in terms of the average shipment cycle time of coalition FFWs, the average shipment cycle time of non-coalition FFWs, and the total distance traveled by the coalition fleet, suggesting that horizontal cooperation in this context was not always beneficial, contrary to what previous studies on horizontal cooperation have found. Since dock capacity constitutes a significant constraint on operations in air cargo hubs, this paper also investigates the effect of dock capacity utilization and horizontal cooperation on the performance of consolidation policies implemented by the coalition. Thus, we built a general model of the air cargo terminal to analyze the effects caused by dock capacity utilization without the added complexity of landside operations at Amsterdam Airport to investigate whether the results hold for more general scenarios. Results from the general simulation model suggest that, in scenarios where dock and truck capacity become serious constraints, the average shipment cycle times of non-coalition FFWs are reduced at the expense of an increase in the cycle times of FFWs who constitute the coalition. A good balance among all the performance measures considered in this study is reached by following a policy that takes advantage of consolidating shipments based on individual visits to GH.
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KLM has revealed the plan to downsize the full-freight cargo fleet in Schiphol Airport, for that reason the company requires to explore the consequences of moving the cargo transported by the full freighters into the bellies of the passenger flights. In this study, the authors analyze the implications of this decision by considering the variability of the load factors and the impact that replacing old aircraft might have. The study addresses how the transition towards the belly operation should impact the current operation of KLM at Schiphol. Our study shows that the replacement of old aircraft with new 787s and 777s will have significant effect on the cargo capacity of the company. The results rise the discussion on future problems to be faced and how to make the transition from full freighter to belly operation.
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The transition from diesel-driven urban freight transport towards more electric urban freight transport turns out to be challenging in practice. A major concern for transport operators is how to find a reliable charging strategy for a larger electric vehicle fleet that provides flexibility based on different daily mission profiles within that fleet, while also minimizing costs. This contribution assesses the trade-off between a large battery pack and opportunity charging with regard to costs and operational constraints. Based on a case study with 39 electric freight vehicles that have been used by a parcel delivery company and a courier company in daily operations for over a year, various scenarios have been analyzed by means of a TCO analysis. Although a large battery allows for more flexibility in planning, opportunity charging can provide a feasible alternative, especially in the case of varying mission profiles. Additional personnel costs during opportunity charging can be avoided as much as possible by a well-integrated charging strategy, which can be realized by a reservation system that minimizes the risk of occupied charging stations and a dense network of charging stations.
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The paper discusses the growing importance of urban freight research given the increasing urban population trends. The complexity of urban freight systems means that it is essential for the public and private sectors to work together - one way to achieve this has been through freight partnerships. A short review of freight partnerships highlights the way in which they have fostered mutual understanding among urban freight stakeholders. The literature on shared situational awareness (SSA) and joint knowledge production (JKP) has been adapted to position freight partnerships and to further develop and link these partnerships to the concept of a living laboratory concerned with urban freight transport. This novel application of the living lab concept is introduced. Next, the first phases of a city logistics living lab brought in practice in Rotterdam are shortly mentioned. The living lab concept fits the complexities of the urban freight system well and has been a cornerstone of a recently started major freight project in the EU (CITYLAB). © 2016 Published by Elsevier B.V.
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The number of light commercial vehicles (LCV) in cities is growing, which puts increasing pressure on the livability of cities. Freight vehicles are large contributors to polluting air and CO2 emissions and generate problems in terms of safety, noise and loss of public space. Small electric freight vehicles and cargo bikes can offer a solution, as they take less space, can maneuver easily and do not emit local pollution. There is an increasing interest in these vehicle, called light electric freight vehicles (LEFV’s), among logistic service providers in European cities. However, various technical and operational challenges impede large scale implementation. Within the two-year LEVV-LOGIC project, (2016-2018) the use of LEFV’s for city logistics is explored. The project combines expertise on logistics, vehicle design, charging infrastructure and business modelling to find the optimal concept in which LEFV’s can be a financial competitive alternative for conventional freight vehicles. This contribution to EVS30 will present the project’s first year results, showing the guideline for and the applied design of LEFV for future urban city logistics.
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The demand for the transport of goods within the city is rising and with that the number of vans driving around. This has adverse effects on air quality, noise, safety and liveability in the city. LEFVs (Light Electric Freight Vehicles) offer a potential solution for this. There is already a lot of enthusiasm for the LEFVs and several companies have started offering the vehicles. Still many companies are hesitating to start and experience. New knowledge is needed of logistics concepts for the application of LEFVs. This paper shows the outcomes of eight case studies about what is needed to successfully deploy LEFVs for city logistics.
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Recently KLM has revealed the plan to downsize the full-freight cargo fleet in Schiphol Airport, for that reason it is important for the company and the airport to explore the consequences of moving the cargo transported by the full freighters into the bellies of the passenger flights. The consequences of this action in terms of capacity and requirements are still unknown for the stakeholders. The current study illustrates that once the freighters are phased out, the commercial traffic needs to adjust mainly their load factors in order to absorb the cargo that was previously transported by the full freighters. The current model is a version that includes the airside operation of the airport and also the vehicle movement which allows addressing the uncertainties of the operation as well as the limitations and potential problems of the phasing-out action.
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The constant growth of air traffic, especially in Europe, is putting pressure on airports, which, in turn, are suffering congestion problems. The airspace surrounding airport, terminal manoeuvring area (TMA), is particularly congested, since it accommodates all the converging traffic to and from airports. Besides airspace, airport ground capacity is also facing congestion problems, as the inefficiencies coming from airspace operations are transferred to airport ground and vice versa. The main consequences of congestion at airport airspace and ground, is given by the amount of delay generated, which is, in turn, transferred to other airports within the network. Congestion problems affect also the workload of air traffic controllers that need to handle this big amount of traffic.This thesis deals with the optimization of the integrated airport operations, considering the airport from a holistic point of view, by including operations such as airspace and ground together. Unlike other studies in this field of research, this thesis contributes by supporting the decisions of air traffic controllers regarding aircraft sequencing and by mitigating congestion on the airport ground area. The airport ground operations and airspace operations can be tackled with two different levels of abstractions, macroscopic or microscopic, based on the time-frame for decision-making purposes. In this thesis, the airport operations are modeled at a macroscopic level.The problem is formulated as an optimization model by identifying an objective function that considers the amount of conflicts in the airspace and capacity overload on the airport ground; constraints given by regulations on separation minima between consecutive aircraft in the airspace and on the runway; decision variables related to aircraft entry time and entry speed in the airspace, landing runway and departing runway choice and pushback time. The optimization model is solved by implementing a sliding window approach and an adapted version of the metaheuristic simulated annealing. Uncertainty is included in the operations by developing a simulation model and by including stochastic variables that represent the most significant sources of uncertainty when considering operations at a macroscopic level, such as deviation from the entry time in the airspace, deviation in the average taxi time and deviation in the pushback time. In this thesis, optimization and simulation techniques are combined together by developing two methods that aim at improving the solution robustness and feasibility. The first method acts as a validation tool for the optimized solution, and it improves the robustness of solution by iteratively fine-tuning some of the optimization model input parameters. The second method embeds the optimization in a simulation environment by taking full advantage of the sliding window approach and creating a loop for a continuous improvement of the optimized solution at each window of the sliding window approach. Both methods prove to be effective by improving the performance, lowering the total amount of conflicts up to 23.33% for the first method and up to 11.2% for the second method, however, in contrast to the deterministic method, the two methods they are not able to achieve a conflict-free scenario due to the effect of uncertainty.In general, the research conducted in this thesis highlights that uncertainty is a factor that affects to a large extent the feasibility of optimized solution when applied to real-world instances, and it, moreover, confirms that using simulation together with optimization has the potentiality toivdeal with uncertainty. The framework developed can be potentially applied to similar problems and different optimization solving methods can be adapted to it.Keywords: Optimization, Simulation, Integrated airport operations, Uncertainty
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In the city of Amsterdam commercial transport is responsible for 15% of vehicles, 34% of traffic’s CO2 emissions and 62% of NOx emissions. The City of Amsterdam plans to improve traffic flows using real time traffic data and data about loading and unloading zones. In this paper, we present, reflect, and discuss the results of two projects from the Amsterdam University of Applied Sciences with research partners from 2016 till 2018. The ITSLOG and Sailor projects aim to analyze and test the benefits and challenges of connecting ITS and traffic management to urban freight transport, by using real-time data about loading and unloading zone availability for rerouting trucks. New technologies were developed and tested in collaboration with local authorities, transport companies and a food retailer. This paper presents and discusses the opportunities and challenges faced in developing and implementing this new technology, as well as the role played by different stakeholders. In both projects, the human factor was critical for the implementation of new technologies in practice.
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The number of light commercial vehicles (LCV) in cities is growing, which puts increasing pressure on the liveability of cities. Small electric freight vehicles and cargo bikes can offer a solution, as they take less space, can manoeuvre easily and free from polluting emissions. Within the two-year LEVV-LOGIC project, (2016-2018) the use of light electric freight vehicles (LEFVs) for city logistics is explored. The project combines expertise on logistics, vehicle design, charging infrastructure and business modelling to find the optimal concept. This paper presents guidelines for the design of LEFV based on the standardized rolling container (length 800 mm, width 640 mm, height 1600 mm) and for the charging infrastructure.
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