Search results for " Ferrovie"
showing 10 items of 383 documents
Evaluation of Roundabout Safety Performance through Surrogate Safety Measures from Microsimulation
2018
The paper presents a microsimulation-based approach for roundabout safety performance evaluation. Based on a sample of Slovenian roundabouts, the vehicle trajectories exported from AIMSUN and VISSIM were used to estimate traffic conflicts using the Surrogate Safety Assessment Model (SSAM). AIMSUN and VISSIM were calibrated for single-lane, double-lane and turbo roundabouts using the corresponding empirical capacity function which included critical and follow-up headways estimated through meta-analysis. Based on calibration of the microsimulation models, a crash prediction model from simulated peak hour conflicts for a sample of Slovenian roundabouts was developed. A generalized linear model…
Accounting for dispersion and correlation in estimating Safety Performance Functions. An overview starting from a case study
2013
In statistical analysis of crash count data, as well as in estimating Safety Performance Functions (SPFs), the failure of Poisson equidispersion hypothesis and the temporal correlation in annual crash counts must be considered to improve the reliability of estimation of the parameters. After a short discussion on the statistical tools accounting for dispersion and correlation, the paper presents the methodological path followed in estimating a SPF for urban four-leg, signalized intersections. Since the case study exhibited signs of underdispersion, a Conway-Maxwell-Poisson Generalized Linear Model (GLM) was fitted to the data; then a quasi-Poisson model in the framework of Generalized Estim…
Potentialities of a Highway Alignment Optimization Method in an I-BIM Environment
2019
The BIM (Building Information Modeling) approach potential in the civil engineering field opened novel scenarios in the design idea concept, from planning to executive and constructive phases. The related advantages are numerous and not only limited to a real-time interaction among the involved subjects, that can actually operate in an optimized 3D shared environment. Owing to the sharing information philosophy and to the features of various "smart objects" combined in the project, this innovation reduces potential errors and increases the effectiveness of the design solution in terms of both functionality and cost. Despite these advantages, the highway alignment design problem remains very…
THE DIAGNOSIS OF ROAD SURFACE DISTRESSES THROUGH IMAGE-BASED MODELING TECHNIQUES. EXPERIMENTAL SURVEY ON LABORATORY-RUTTED SAMPLES
2015
In the past few years, there has been a drastic increase in the use of image-based modeling (IBM) techniques to create high quality, reality-based 3D models. The low costs of these techniques, as well as their attractive visual quality, have led many researchers and professionals to invest their energy and resources in several tests. IBM is rarely used in the field of road surface distresses as diagnosis is usually performed using other techniques and devices. Road safety statistics reveal that about a half of the total number of accidents occur mainly due to the deterioration of the pavement. The goal of effective road network management is often incompatible with economic resources design…
IMAGE ANALYSIS FOR DETECTING THE TRANSVERSE PROFILE OF WORN-OUT RAILS
2012
Abstract — Over its useful life a railway track is subject to many mechanical and environmental stresses which gradually lead to its deterioration. Monitoring the wear condition of the railway superstructure is one of the key points to guarantee an adequate safety level of the railway transport system; in this field, the use of high-efficiency laser techniques has become consolidated and implemented in diagnostic trains (e.g. the “Archimede train” and the “Talete train” ) which allow to detect the track geometric parameters (gauge, alignment, longitudinal level, cross level, superelevation defect, etc.) and the state of rail wear (vertical, horizontal, 45-degree etc.) with very high accurac…
Image analysis for detecting aggregate gradation in asphalt mixture from planar images
2012
Abstract The mechanical properties of bituminous mixture strongly depend on the gradation of the aggregate that represents the mineral skeleton of the mixture, since for open and gap-graded mixtures, stresses due to vehicles in movement on the pavement are mainly transmitted through their contacts. Internal structure of bituminous mixture is, therefore, of great interest for road and infrastructure engineering and it is appropriate to study it with recently developed image analysis method. The purpose of this study was to finalize an effective analysis of asphalt section image for automatically extracting aggregate gradation without the need of separation of the bitumen from the aggregate. …
Valuing the effects of urban road-network projects: a methodological proposal
2006
This paper proposes a methodology for the valuation of the urban environment. It tries to answer questions and problems that derive from new road installations, or functional requalifications in existing road infrastructures, in accordance with specific practices already well-known as Urban Impact Assessment (UIA). More generally, the objective of the urban impact assessment consists of valuing the possibilities to localize urban installations, also considering both their economic and social effects, as well as identifying potential dangers to the environment, intended in a general sense. This kind of valuation distinguishes from the traditional environmental impact valuation (e.g., applied…
Modelling pavement surface characteristics for noise prediction through Bailey-related indicators
2021
The aggregate gradation of bituminous mixtures (hot mix asphalts, HMA) is one of the major factors affecting their surface texture. In turn, this latter is a crucial factor and influences drivers and bystanders’ safety, comfort, and health. Despite this, the design of texture levels still lacks sound bases and dedicated algorithms and this negatively affects the acoustic design of bituminous mixtures. Consequently, the objectives of this study were confined into the derivation of relationships to be used in mix design to predict texture levels. Experimental data were analyzed, in the pursuit of setting up appropriate models and algorithms. Analyses involved the consideration of Bailey-relat…
Infrastrutture ferroviarie, metropolitane, tranviarie e per ferrovie speciali. Elementi di pianificazione e di progettazione.
2017
Il volume presenta i criteri fondamentali di progettazione geometrico-funzionale delle infrastrutture per i sistemi di trasporto a guida vincolata tra i quali si annoverano sia quelli extraurbani, come le ferrovie convenzionali e ad alta velocità, sia quelli urbani come le metropolitane (“pesanti”, “leggere” ed “automatiche”), le tranvie ed i people movers. Per ogni sistema di trasporto sono descritti gli orientamenti tecnici – progettuali e costruttivi - ritenuti più rilevanti, le peculiarità trasportistiche (ad esempio i valori di capacità) ed i principali riferimenti normativi adottati per la definizione dei singoli elementi compositivi del tracciato delle linee, delle stazioni e delle f…
Machine learning techniques to estimate the degree of binder activity of reclaimed asphalt pavement
2022
Part of this research was funded by the project RTI2018-096224-J-I00 that has been cofounded by the Spanish Ministry of Science and Innovation, inside the National Program for Fostering Excellence in Scientific and Technical Research, National Subprogram of Knowledge Generation, 2018 call, in the framework of the Spanish National Plan for Scientific and Technical Research and Innovation 2017-2020, and by the European Union, through the European Regional Development Fund, with the main objective of Promoting technological development, innovation and quality research. Part of this work was financially supported by the Italian Ministry of University and Research with the research Grant PRIN 20…