Search results for "Transportation"
showing 10 items of 860 documents
Energy-environmental and cost assessment of a set of strategies for retrofitting a public building toward nearly zero-energy building target
2017
Abstract The purpose of this study was to assess an energy retrofit of a building representative of those in public tertiary stock, to improve energy performance toward nearly Zero-Energy Building (nZEB) requirements. The building is located in the campus of the Politecnico di Milano University (Italy). Several hypothetical improvements regarding the building envelope and plants were assessed in terms of energy savings, costs, and the reduction of greenhouse gas emissions. The results of the study show that it is possible to reduce primary energy demand and associated emissions up to 40% from the current values by adopting market-available and well-proven technological solutions for retrofi…
Modeling traffic safety at urban four leg-signalized intersections
2013
According to the state-of-the-art of the methodologies, the development of safety performance functions (SPFs) for road sections and intersections requires the employment of statistical models to predict expected crash frequencies on the basis of traffic volumes and site characteristics to be surveyed and used as input to models. Nevertheless, literature reports several studies on issues deriving from data features or methodological approaches that may invalidate the efficiency of the models and the accuracy of the estimates. Drawing inspiration from the above mentioned considerations, the objective of this study is to develop safety performance functions for a sample of urban four leg-sign…
The potential of rotorcraft for intercity passenger transport
2007
Abstract There are many high-speed rail projects in Europe at different stages of development. They are supported on environmental grounds and as a means of reducing congestion on other modes, including aviation. High-speed rail, however requires major investment costs, takes a long time to come online, and involves considerable financial risks. A potential alternative that overcomes some of these problems makes use of rotorcrafts. This paper assesses the potentiality of civil rotorcrafts as part of the air transport system. Discrete mode choice models are used to forecast traveller choice behaviour when the rotorcraft is introduced and financial evaluations performed looking at the operati…
Applying complexity science to air traffic management
2015
Versión aceptada obtenida del archivo digital en línea WestminsterResearch de la Universidad de Westminster. Complexity science is the multidisciplinary study of complex systems. Its marked network orientation lends itself well to transport contexts. Key features of complexity science are introduced and defined, with a specific focus on the application to air traffic management. An overview of complex network theory is presented, with examples of its corresponding metrics and multiple scales. Complexity science is starting to make important contributions to performance assessment and system design: selected, applied air traffic management case studies are explored. The important contexts of…
Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
2016
Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…
Proposal of geographic information systems methodology for quality control procedures of data obtained in naturalistic driving studies
2015
The primary goal of naturalistic driving studies is to provide a comprehensive observation of the driver's behaviour under real-life conditions by measureing a great number of parameters at high temporal frequencies. Achieving this goal, however, is a complex endeavor that faces many challenges such as the complexity of the vehicle instrumentation during the phase of data collection, and the difficult handling of large data volumes during the phase of data analysis. These drawbacks often cause episodes of data losses. Improving the technical aspects of the collection of naturalistic data is of paramount importance to increase the return of the investment made in it. An aspect to consider is…
Environmental, functional and economic criteria for comparing “target roundabouts” with one- or two-level roundabout intersections
2015
The article describes a criterion based on functional, environmental and economic aspects for comparing conventional roundabouts with innovative one- or two-level roundabouts. We compared the performances of eight roundabout types, differing in geometric layout, number of lanes and traffic flow regulation from each other, with regard to vehicle delays and CO2, NOx, PM2.5 and PM10 pollutant emissions. Recently-designed roundabouts - target roundabouts and flyover roundabouts - have also been studied for their undoubted practical interest. By means of closed-form capacity models and CORINAIR methodology, several traffic simulations were carried out to examine a typical annual traffic demand c…
Car following: Comparing distance-oriented vs. inertia-oriented driving techniques
2018
The rationale behind most car-following (CF) models is the possibility to appraise and formalize how drivers naturally follow each other. Characterizing and parametrizing Normative Driving Behavior (NDB) became major goals, especially during the last 25 years. Most CF models assumed driver propensity for constant, safe distance is axiomatic. This paper challenges the idea of safety distance as the main parameter defining a unique (or natural) NDB. Instead, it states drivers can adapt to reactive and proactive car following. Drawing on recent CF models close to the Nagoya paradigm and on other phenomena (e.g., wave movement in Nature), we conceived car following by Driving to keep Inertia (D…
Implementation of the driver training curriculum in Spain – An analysis based on the Goals for Driver Education (GDE) framework
2014
Abstract The Goals for Driver Education (GDE) framework represents a conceptual outline of the goals to be satisfied in driver education (Hatakka et al., 2002). We aimed to analyze the implementation of the driver training curriculum in Spain, taking this framework as reference; the Spanish driving instructors was the target population from which to gather the information to be analyzed. For this purpose, we developed the DTCI (Driver Training Curriculum Implementation) scale as well as a number of questions concerning the driving instructors’ opinions about their own training as instructors, and they were included in a survey that provided information for a probabilistic sample of 676 driv…
Split-Delivery Capacitated Arc-Routing Problem: Lower Bound and Metaheuristic
2010
International audience; This paper proposes lower and upper bounds for the split-delivery capacitated arc-routing problem (SDCARP), a variant of the capacitated arc-routing problem in which an edge can be serviced by several vehicles. Recent papers on related problems in node routing have shown that this policy can bring significant savings. It is also more realistic in applications such as urban refuse collection, where a vehicle can become full in the middle of a street segment. This work presents the first lower bound for the SDCARP, computed with a cutting plane algorithm and an evolutionary local search reinforced by a multistart procedure and a variable neighborhood descent. Tests on …