Search results for "Strade"

RILEM TC 279 WMR round robin study on waste polyethylene modified bituminous binders: advantages and challenges

2022

inter-laboratory experiments were designed to evaluate the impact of plas- tic waste blended directly in bitumen and to assess the properties, using conventional and advanced bituminous binder testing. The blends tar- geted 5% of plastic waste in 95% bitumen, using two types of polyethy- lene (PE) primary (pellets) and secondary (shreds) waste. The experiments showed that the addition of PE waste to bitumen does not alter the chem- istry of the bitumen, the blending is physical. The DSR results indicate a strong dependency on the testing temperature as at low temperatures the composite material bitumen and PE behave both elastically whereas, at higher temperatures, the bitumen becomes visco…

An algorithm based on the PPC (Polynomial Parametric Curve) for designing horizontal highway alignments

2015

Criteria for geometric design of highway alignments have been studied in various researches so far, providing new methods, as alternative to traditional approaches. They can be useful for obtaining better solutions, characterized by high performances in terms of motion safety and comfort. In particular, continuous curvature alignments, based on polynomial functions, are highly consistent solutions with users' driving behaviour and vehicle trajectories. Moreover, alignment geometry optimization allows engineers to minimize dynamic effects on drivers with considerable advantages in terms of comfort and safety. This paper carries on the research of a previous study, in which a polynomial param…

A Stochastic Decision Process Model for Optimization of Railway and Tramway Track Maintenance by means of Image Processing Technique

2013

One of the key targets for an efficient transport network management is the search for proper maintenance policies to guarantee acceptable safety and quality standards in the travel and to optimize available resource allocation. Methodologically, the proposed model presented in this paper uses the stochastic dynamic programming and in particular Markov decision processes applied to the rail wear conditions for the railway and tramway network. By performing the integrated analysis of the classes of variables which characterize the rail quality (in terms of safety), the proposed mathematical approach allows to find the solutions to the decision-making process related to the probability of det…

A multidisciplinary approach using LCCA and micro-simulation 10 model for the management of the urban pavements

2013

The maintenance and the rehabilitation of the urban road pavements are not often based on systematic program and scheduling but rather on emergency or on other not identified reasons. Moreover the Life Cycle Cost Analysis (LCCA), the only peculiar procedure for the management pavement, finds its own application for highway and motorway, even if it is possible to search the best investment for the urban interstate and arterials. By the light of the quantity of the involved resources, it seems necessary to define an operative methodology for programming the maintenance and rehabilitation activities for the urban pavement. The paper is oriented towards the development of a multidisciplinary ap…

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…