Open Access
Using modelling techniques to analyze urban freight distribution. A case study in Pamplona (Spain)
(Elsevier, 2018) Alvarez Indave, Pablo; Serrano Hernández, Adrián; Faulín Fajardo, Javier; Juan Pérez, Ángel Alejandro; Institute of Smart Cities - ISC
The city of Pamplona, in Spain, is currently experiencing several changes regarding sustainable mobility such as pedestrianization of some streets in the city center, and access control to the Old Town for motor vehicles through the use of automatic number-plate recognition. However, some groups including local neighbors and businesses are raising complaints as they are being affected by these measures. This is also the case for couriers and logistics companies which have now to comply with new regulations regarding delivery routes throughout the Old Town. This paper will present a comprehensive study of the situation that is being carried out, and in which social perceptions and freight traffic patterns in the Old Town of Pamplona are analyzed to understand how urban freight distribution could be improved in the area. For this purpose, we make use of a survey-based research to the stakeholders, i.e. pedestrians, logistics companies, retailers, and authorities of Pamplona. Results highlight pollution derived from transportation, lack of parking spaces as well as invasion of public spaces in the city center as the key issues for improving freight transportation in the Old Town. Finally, placing a distribution center in the Old Town and the promotion of the cycle-logistics are considered as the future of the urban distribution in Pamplona.
Open Access
Managing transportation externalities in the Pyrenees region: measuring the willingness-to-pay for road freight noise reduction using an experimental auction mechanism
(Elsevier, 2018) Denant-Boemont, Laurent; Faulín Fajardo, Javier; Hammiche, Sabrina; Serrano Hernández, Adrián; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas
The estimation of the noise impact caused by road freight transportation is critical to have acknowledgment of the ambiance pollution caused by road traffic crossing geographical areas containing important natural resources. Thus, our work proposes a within-subject survey where a Contingent Valuation Method (CVM) is combined with a laboratory economic experimental auction. Our study objective is to measure the willingness-to-pay (WTP) for reducing traffic noise nuisances due to freight transportation in the region of Navarre, Spain. A special focus is made regarding the measurement of the hypothetical bias, when a comparison is done between hypothetical WTP, coming from the CVM study, with real-incentivized one, as the outcome of the economic experiment. Additionally, statistical analyses are conducted in order to find explanation factors for these outcomes. Results suggest a strong evidence for an upward hypothetical bias (from 50% to 160%) indicating the income, the educational level, the gender, and the age as the main factors which explain that bias.
Open Access
Internalizing negative externalities in vehicle routing problems through green taxes and green tolls
(Institut d'Estadística de Catalunya (Idescat), 2019) Serrano Hernández, Adrián; Faulín Fajardo, Javier; Institute of Smart Cities - ISC
Road freight transportation includes various internal and external costs that need to be accounted for in the construction of efficient routing plans. Typically, the resulting optimization problem is formulated as a vehicle routing problem in any of its variants. While the traditional focus of the vehicle routing problem was the minimization of internal routing costs such as travel distance or duration, numerous approaches to include external factors related to environmental routing aspects have been recently discussed in the literature. However, internal and external routing costs are often treated as competing objectives. This paper discusses the internalization of external routing costs through the consideration of green taxes and green tolls. Numeric experiments with a biased-randomization savings algorithm, show benefits of combining internal and external costs in delivery route planning.
Open Access
Determining an optimal area to locate a biorefinery under economic and environmental criteria
(Elsevier BV, 2017) Serrano Hernández, Adrián; Faulín Fajardo, Javier; Pintor Borobia, Jesús María; Belloso Ezcurra, Javier; Institute for Advanced Materials and Mathematics - INAMAT2
Facilities location is a strategic decision which has to be carefully considered because it could involve the failure or success of a business. For that reason, anything that helps decision makers to facilitate their location decision processes is of their utmost interest. The aim of this paper is, therefore, providing a methodology that could be useful for the decision makers by giving them not only an optimal point but also a whole region where they can focus on their attention. Knowing that biofuels are settling as a new alternative energy source which has been spreading around the world to reduce greenhouse gas emissions and oil dependence, this methodology is tested in the real case of locating a biorefinery in Navarre, Spain. Moreover, A Mixed Integer Linear Programming (MILP) model has been developed to generate optimal region vertices as well as some other supply chain characteristics, including, among others, which crops are going to be harvested, when they are going to be collected, and their storage levels. Additionally, two criteria were implemented in MILP model to create two optimal regions: one considering an economic criterion and other one minimizing environmental impact. As a result, two regions were drawn in the Navarrese territory that point out where a biorefinery should be located and how the supply chain should be designed.
Open Access
Pricing and internalizing noise externalities in road freight transportation
(Elsevier, 2017) Serrano Hernández, Adrián; Alvarez Indave, Pablo; Lerga Valencia, Iosu; Reyes-Rubiano, Lorena Silvana; Faulín Fajardo, Javier; Institute of Smart Cities - ISC
People living close to main roads may suffer from the nuisance of traffic and noise pollution. This paper assesses the effect of full routing cost in vehicle routing decisions by internalizing the external cost of noise. On a first step, noise externalities are economically assessed through a contingent valuation procedure. Secondly, a novel methodology is proposed to allocate the external costs to the road network links. Results show significant differences in routing planning depending on the approach: minimization of traditional internal cost versus minimization of full cost. These results encourage further research in pricing and methodologies to internalize externalities.
Open Access
Urban e-grocery distribution design in Pamplona (Spain) applying an agent-based simulation model with horizontal cooperation scenarios
(MDPI, 2021) Serrano Hernández, Adrián; Torre Martínez, Rocío de la; Cadarso, Luis; Faulín Fajardo, Javier; Institute of Smart Cities - ISC; Institute for Advanced Research in Business and Economics - INARBE
E-commerce has boosted in the last decades because of the achievements of the information and telecommunications technology along with the changes in the society life-style. More recently, the groceries online purchase (or e-grocery), has also prevailed as a way of making the weekly shopping, particularly, the one including fresh vegetables and fruit. Furthermore, this type of virtual shopping in supermarkets is gaining importance as the most efficient delivery system in cost and time. Thus, we have evaluated in this study the influence of the cooperation-based policies on costs and service quality among different supermarkets in Pamplona, Spain. Concerning methodology, first of all, we carried out a survey in Pamplona having the purpose of modelling the demand patterns about e-grocery. Second, we have developed an agent-based simulation model for generating scenarios in non-cooperative, limited cooperation, and full cooperation settings, considering the real data obtained from the survey analysis. At this manner, Vehicle Routing Problems (VRP) and Multi Depot VRPs (MDVRP) are dynamically generated and solved within the simulation framework using a biased-randomization algorithm. Finally, the results show significant reductions in distance driven and lead times when employing horizontal cooperation in e-grocery distribution.
Open Access
Optimizing energy consumption in transportation: literature review, insights, and research opportunities
(MDPI, 2020) Corlu, Canan Gunes; Torre Martínez, Rocío de la; Serrano Hernández, Adrián; Juan Pérez, Ángel Alejandro; Faulín Fajardo, Javier; Institute for Advanced Research in Business and Economics - INARBE; Institute of Smart Cities - ISC
From airplanes to electric vehicles and trains, modern transportation systems require large quantities of energy. These vast amounts of energy have to be produced somewhere—ideally by using sustainable sources—and then brought to the transportation system. Energy is a scarce and costly resource, which cannot always be produced from renewable sources. Therefore, it is critical to consume energy as efficiently as possible, that is, transportation activities need to be carried out with an optimal intake of energetic means. This paper reviews existing work on the optimization of energy consumption in the area of transportation, including road freight, passenger rail, maritime, and air transportation modes. The paper also analyzes how optimization methods—of both exact and approximate nature—have been used to deal with these energy-optimization problems. Finally, it provides insights and discusses open research opportunities regarding the use of new intelligent algorithms—combining metaheuristics with simulation and machine learning—to improve the efficiency of energy consumption in transportation.
Open Access
A strategic multistage tactical two-stage stochastic optimization model for the airline fleet management problem
(Elsevier, 2020) Serrano Hernández, Adrián; Cadarso, Luis; Faulín Fajardo, Javier; Institute of Smart Cities - ISC
This work proposes stochastic optimization for the airline fleet management problem, considering uncertainty in the demand, operational costs, and fares. In particular, a multistage tree is proposed, compounded of strategic and tactical nodes. At the former ones, fleet composition decisions are made, while at the latter ones, aircraft assignment decisions are formulated. Computational experiments are based on a small air network with seven strategic nodes and fourteen tactical nodes (i.e., seasons) where two fleet types are available to be included: Airbus 320, and Boeing 737. These results provide the optimal fleet planning and assignment at both strategic and tactical scopes. Finally, it is shown the superior performance of the stochastic version of this problem against the deterministic one.
Open Access
Horizontal collaboration in freight transport: concepts, benefits and environmental challenges
(Institut d'Estadística de Catalunya, 2017) Serrano Hernández, Adrián; Juan Pérez, Ángel Alejandro; Faulín Fajardo, Javier; Pérez Bernabeu, Elena; Estatistika eta Ikerketa Operatiboa; Institute of Smart Cities - ISC; Estadística e Investigación Operativa
Since its appearance in the 1990s, horizontal collaboration (HC) practices have revealed them-selves as catalyzers for optimizing the distribution of goods in freight transport logistics. After introducing the main concepts related to HC, this paper offers a literature review on the topic and provides a classification of best practices in HC. Then, the paper analyses the main benefits and optimization challenges associated with the use of HC at the strategic, tactical, and operational levels. Emerging trends such as the concept of ‘green’ or environmentally-friendly HC in freighttransport logistics are also introduced. Finally, the paper discusses the need of using hybrid optimization methods, such as simheuristics and learnheuristics, in solving some of the previously identified challenges in real-life scenarios dominated by uncertainty and dynamic conditions.
Open Access
Locating a biorefinery in Northern Spain: decision making and economic consequences
(Elsevier, 2019) Serrano Hernández, Adrián; Faulín Fajardo, Javier; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua, IIM14196.RI1
Biofuels are emerging as a prominent renewable and sustainable energy sources in developed countries. In this sense, this paper presents a case study in which a biorefinery has to be sited in Northern Spain. Thus, the strategic decision of locating such a facility is deeply investigated through strategic policy evaluation. Then, tactical decisions ranging from purchasing and transportation policies to storage protocols are carried out. Only local and limited biomass can be harvested for supplying the biorefinery through a heterogeneous vehicle fleet. Moreover two different and mutually exclusive storage strategies are evaluated: direct supply from crops to biorefinery and using intermediate-collectors. Additionally, crop exploitation factors and biorefinery sizes are used to generate several scenarios in which the strategic decision of location as well as all the tactic decisions are made. Some mixed integer linear programming models are proposed to figure out all relevant decision problems. The results suggest that the Northwest study area as the best option to locate the biorefinery and recommend the intermediate-collector storage strategy. Moreover, the key information about critical biomass, crops and times are also provided.