Search results for " Ferrovie Ed Aeroporti"

Apparato per tracciare lo stato della superficie di un pavimento e procedimento di bilanciamento dinamico di un tale apparato

2016

Approccio teorico-sperimentale per l'analisi delle condizioni opertaive di rotatorie urbane non convenizonali.

2008

I metodi tradizionali di analisi delle intersezioni a rotatoria non consentono una valutazione attendibile delle condizioni operative del traffico in presenza di schemi organizzativi dell’intersezione, nei quali la geometria, unitamente alla molteplicità delle situazioni di traffico ed all’inserimento in contesti vincolati, induce comportamenti di guida anche molto distanti da quelli osservabili in rotatorie convenzionali. Quanto evidenziato interessa, in particolare, gli schemi circolari di intersezione in area urbana, dove risultano particolarmente diffusi e si caratterizzano per requisiti geometrico-funzionali spesso distanti da quelli propri delle rotatorie convenzionali. I vincoli loca…

Conversion of existing roundabouts into turbo-roundabouts: case studies from real world, Journal of Civil Engineering and Architecture 6(8)

2012

Compared with roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of vehicles through the intersection; they both can improve road safety conditions at the junction. Moreover, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. The present paper has three main objectives : 1) to discuss general design criteria and functional principles of turbo roundabouts; 2) to give the geometric d…

TURBO-ROUNDABOUT GENERAL DESIGN CRITERIA AND FUNCTIONAL PRINCIPLES: CASE STUDIES FROM REAL WORLD

2010

Compared with usual roundabouts the main advantages of turbo-roundabouts are the reduction in the number of potential conflicting points and the lower speed of passing vehicles through the intersection; they both can improve road safety conditions at the junction. Also, the physical delimitation among lanes limits the side-by-side accident risk. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. In a previous paper authors proposed a theoretical approach to evaluate turbo-roundabouts capacity founded on gap acceptance theory. In particular, …

Safety diagnostic method in urban circular intersections

2004

The available knowledge of traffic safety at roundabouts is not a complete reference for geometric design; where there are organizational schemes for junctions characterized by a geometric design, quite different driving behaviours are required from those that are observable at roundabouts. This is very frequent in urban areas, where the existing constraints, particularly physical ones, often render it necessary to make “compromise choices” relating to one or more geometric features of the roundabout (central island shape, circulatory roadway width, symmetry and number of the arms, entry width, etc). The objective of this study is to explain the accident phenomenology of this kind of road s…

An Italian experience on crash modeling for roundabouts

2015

In the last few years a considerable amount of safety models and evaluation tasks have been developed and specifically dedicated to roundabouts. Several safety performance functions (SPFs), indeed, have been implemented for roundabouts worldwide. Since SPFs are developed using crashes, traffic volume and other characteristics of a specific site (or geographical area), their direct transferability to other contexts different from those in which SPFs were calibrated is not always possible and, in any case, it must be done very carefully. A safety performance function cannot be used without a transferability evaluation for sites not included in the geographic area for which it was developed. S…

Ruolo dell'infrastruttura nella sicurezza stradale

2010

Ottimizzazione degli aspetti tecnici ed economici nella gestione della sicurezza in galleria

2010

Integrating vehicle specific power methodology and microsimulation in estimating emissions on urban roundabouts

2021

In this study pollutant emissions were estimated from VSP modal emission rates and the distribution of time spent in each VSP mode obtained from the speed profiles both gathered in the field and simulated in AIMSUN at a sample of urban roundabouts. The versatility of the micro-simulation model for a calibration aimed at improving accuracy of emissions estimates was tested in order to ensure that second-by-second trajectories experienced in the field by a test vehicle through the sampled roundabouts properly reflected the simulated speed profiles. The first results which the thesis will refer, confirmed the feasibility of the smart approach that integrates the use of field-observed and simul…

A microsimulation calibration methodology based on speed-density relationships for freeways

2014

This paper describes the calibration methodology based on speed-density relationships in the microsimulation calibration process, stated that they represent the traffic flow phenomenon in a wide range of operational conditions and well summarize all the information that may be collected on field (or following a run of the microsimulation model) on two of the three key variables of traffic flow. The matching of speed-density relationships from field and simulation was evaluated using statistical analysis as technique of pattern recognition. A test freeway segment under uncongested traffic conditions was selected as case study; based on traffic data observed at A22 Brenner Freeway, Italy, sta…