Data Envelopment Analysis (D.E.A.) for urban road system performance assessment

Improving the efficiency of transport networks by enhancing road system performance, lays the foundations for the positive change process within a city, achieving good accessibility to the area and optimizing vehicle flows, both in terms of cost, management and attenuation of environmental impacts. The performance of an urban road system can be defined according to different thematic areas such as traffic flow, accessibility, maintenance and safety, for which the scientific literature proposes different measurement indicators. However variations in performance are influenced by interventions which differ from one another, such as infrastructure, management, regulation or legislation, etc.. Therefore sometimes it is not easy to understand which areas to act on and what type of action to pursue to improve road network performance. Of particular interest are the tools based on the use of synthetic macro-indicators that are representative of the individual thematic areas and are able to describe the behavior of the entire network as a function of its characteristic elements. These instruments are of major significance when they assess performance not so much in absolute terms but in relative terms, i.e. in relation to other urban areas comparable to the one being examined. Therefore the objective of the proposed paper is to compare performances of different urban networks, using a non-parametric linear programming technique such as Data Envelopment Analysis (DEA), Farrel (1957), in order to provide technical support to the policy maker in the choice of actions to be implemented to make urban road systems efficient. This work is the conclusive study of road system performance analysis using DEA. The study forms part of a research project supported by grant. PRIN-2009 prot. 2009EP3S42_003, in which the University di Cagliari is a partner with a research team comprising the authors of this paper, and which addresses performance assessment of road networks, Fancello, Uccheddu and Fadda (2013a),(2013b)

Performance assessment of alternative SSS networks by combining KPIs and factor-cluster analysis

Performance assessment is a fundamental tool to successfully monitor and manage logistics and transport systems. In the field of Short Sea Shipping (SSS), the performance of the various maritime initiatives should be analyzed to assess the best way to achieve efficiency and guide related policies. This study proposes a quantitative methodology which can serve as a decision-support tool in the preliminary assessment and comparison of alternative SSS networks. The research is executed via a Mediterranean case study that compares a hypothetical Mediterranean ro-ro SSS network developed in the framework of a past Euro-Mediterranean cooperation project with the network of existing ro-ro liner services operating in the area. Performance benchmarking of the two networks is performed using a set of quantitative Key Performance Indicators (KPIs) and applying a factor-cluster analysis to produce homogeneous clusters of services based on the relevant variables while accounting for sample heterogeneity. Quantitative results mostly confirm the overall better performance of the prospective network and demonstrate that using KPIs and factor-cluster analysis to investigate the performance of maritime networks can provide policymakers with a preliminary wealth of knowledge that can help in setting targeted policy for SSS-oriented initiatives

Towards the IMO’s GHG goals: a critical overview of the perspectives and challenges of the main options for decarbonizing international shipping

The Initial Strategy on reduction of greenhouse gas (GHG) emissions from ships adopted by the International Maritime Organization (IMO) in 2018 commits the IMO to reduce total GHG emissions of shipping by at least 50% by 2050. Though the direction of the Strategy is clear, the path to implementation remains uncertain. The ambitious IMO’s target calls for widespread uptake of lower and zero-carbon fuels, in addition to other energy eciency measures, including operational and market ones. Using a triangulated research approach, this paper provides a critical overview of the main measures and initiatives the shipping industry can adopt to try to cope with the new IMO’s requirements. The pros and cons of the most popular emission reduction options are investigated along with the main challenges and barriers to implementation and the potential facilitators that could foster a wider application. The framework that is outlined is complex and not without controversy. Research can play a key role as a facilitator of shipping’s decarbonization by providing its contribution to overcoming the existing controversies on various decarbonization options and by developing a wealth of knowledge that can encourage the implementation of low-carbon initiatives

A modeling tool for measuring the performance of urban road networks

The aim of this paper is to develop an integrated performance indicator in urban road infrastructure for evaluating network functionality and the impact of transport system interventions. The complex indicator has been elaborated using a multicriteria algorithm, based on concordance analysis. We calibrate a synthetic performance indicator for an urban road network, containing all those elements required for characterizing urban network functionality. Specifically, a series of core indicators is identified, integrated and interlinked. The functionality of an urban road network can be determined by analyzing several aspects that commonly affect operating conditions such as traffic flow, safety, road maintenance conditions, accessibility and environmental impact. No methodology is currently available in the scientific literature for measuring urban road network performance, using indicators that combine information about various aspects: the indicators used in the analysis of transport systems assess performance separately from different perspectives. For example, the quality of traffic flow is measured through the Level of Service (HCM, 2010), accessibility performance is assessed through clustering measures (Jiang & Claramunt, 2004) and safety conditions are measured in terms of number of road accidents (Tingvall, Stigson, Eriksson, Johansson, Krafft & Lie, 2010). This paper proposes a unique modeling tool that incorporates the different indicators used separately to calculate network performance for each area

Investigating last food mile deliveries: A case study approach to identify needs of food delivery demand

© 2017 Drawing on the results of a survey carried out in Cagliari (Italy), the paper provides an analysis of the characteristics of food deliveries in urban areas aimed at understanding the needs and expectations of receivers of last mile deliveries of fresh products. In fact, exploring the needs of potential users - who are directly responsible for the success of the scheme - and the characteristics of logistics flows they generate/attract in the city centre is a necessary prerequisite for implementing city logistics measures. The study considers independent retailers within the hotel, restaurants and catering (Ho.Re.Ca.) sector. Based on the delivery characteristics, a classification of commercial activities related to the food chain is provided. The analysis has been developed by means of Multiple Correspondence Analysis (MCA) and Cluster analysis. The suitability of city logistics measures to the last food mile is also discussed

Data Envelopment Analysis (D.E.A.) for Urban Road System Performance Assessment

AbstractImproving the efficiency of transport networks by enhancing road system performance, lays the foundations for the positive change process within a city, achieving good accessibility to the area and optimizing vehicle flows, both in terms of cost, management and attenuation of environmental impacts. The performance of an urban road system can be defined according to different thematic areas such as traffic flow, accessibility, maintenance and safety, for which the scientific literature proposes different measurement indicators. However variations in performance are influenced by interventions which differ from one another, such as infrastructure, management, regulation or legislation, etc. Therefore sometimes it is not easy to understand which areas to act on and what type of action to pursue to improve road network performance. Of particular interest are the tools based on the use of synthetic macro-indicators that are representative of the individual thematic areas and are able to describe the behavior of the entire network as a function of its characteristic elements. These instruments are of major significance when they assess performance not so much in absolute terms but in relative terms, i.e. in relation to other urban areas comparable to the one being examined. Therefore the objective of the proposed paper is to compare performances of different urban networks, using a non-parametric linear programming technique such as Data Envelopment Analysis (DEA), Farrel (1957), in order to provide technical support to the policy maker in the choice of actions to be implemented to make urban road systems efficient. This work is the conclusive study of road system performance analysis using DEA.The study forms part of a research project supported by grant, PRIN-2009 prot. 2009EP3S42_003, in which the University di Cagliari is a partner with a research team comprising the authors of this paper, and which addresses performance assessment of road networks, Fancello, Uccheddu and Fadda (2013a),(2013b)

Visual Perception and Understanding of Variable Message Signs: The Influence of the Drivers’ Age and Message Layout

Variable message signs (VMS) are used to display messages providing up‐to‐date traffic‐ relevant information so that drivers can safely adapt their behavior in real time. The information reported in a VMS should be brief but comprehensive to minimize perception time. The latter can be influenced by the way the message is displayed. This study investigates how the different ways of displaying the same message can influence reading time and the information perception process at different driving speeds. Specifically, the following message characteristics are investigated: (i) use of uppercase and lowercase letters; (ii) use of familiar pictograms; and (iii) use of less familiar pictograms. Furthermore, as perception time typically changes with ageing, drivers belonging to three different age classes are tested. The experimentation was performed by simulating a vehicle passing along a straight road upon which a VMS displaying different messages was placed. Exper‐ imentation results are analyzed using the Kruskal–Wallis test, Friedman rank‐sum test and Welch one‐way ANOVA, showing that: (i) the use of uppercase or lowercase does not seem to significantly affect reading times; (ii) the use of pictograms that are not very familiar to habitual road‐users can be counterproductive for the perception process; (iii) elderly drivers always have greater difficulty in perceiving the message than young or middle‐aged drivers. The findings of this study can be of help for traffic authorities to design the most suitable structure for a VMS so that its information can be unequivocally and immediately conveyed to drivers

A Port Accessibility Index for Mediterranean container terminals

Using the Mediterranean as an application case, this study defines a Port Accessibility Index (PAI) useful to measure the accessibility of Mediterranean container ports. Traditionally, accessibility is measured as the quality of maritime links that connect ports together, without considering the port’s characteristics. Differently from previous studies, this paper also focuses on the internal accessibility of the port. In so doing, the PAI will combine the Liner Shipping Connectivity Index with other factors, such as, time at port of container ships, maximum quay depth and number of containers per quay crane (QC) or per yard area. The application considers the 34 main Mediterranean container ports in terms of TEUs handled in the last decade. The results can contribute to highlight and identify the potential elements that could improve the accessibility of Mediterranean container ports, providing decision-makers with a useful wealth of knowledge when carrying out management strategies. Future studies may concern the extension of the research to other geographical areas with the inclusion of additional indicators (e.g., road and/or rail accessibility)

Prediction of late/early arrivals in container terminals - A qualitative approach

Vessel arrival uncertainty in ports has become a very common problem worldwide. Although ship operators have to notify the Estimated Time of Arrival (ETA) at predetermined time intervals, they frequently have to update the latest ETA due to unforeseen circumstances. This causes a series of inconveniences that often impact on the efficiency of terminal operations, especially in the daily planning scenario. Thus, for our study we adopted a machine learning approach in order to provide a qualitative estimate of the vessel delay/advance and to help mitigate the consequences of late/early arrivals in port. Using data on delays/advances at the individual vessel level, a comparative study between two transshipment container terminals is presented and the performance of three algorithmic models is evaluated. Results of the research indicate that when the distribution of the outcome is bimodal the performance of the discrete models is highly relevant for acquiring data characteristics. Therefore, the models are not flexible in representing data when the outcome distribution exhibits unimodal behavior. Moreover, graphical visualisation of the importance-plots made it possible to underline the most significant variables which might explain vessel arrival uncertainty at the two European ports