Search results for "aeroporti"
showing 10 items of 387 documents
Effect of ageing on the morphology and creep and recovery of polymer-modified bitumens
2018
Polymer additives are used to improve the properties of road bitumens including their oxidative resistance. However, their usage as anti-oxidative materials remains relatively unclear. This study aims to investigate the changes in the morphology and the rheological response of polymer modified bitumens used in road pavement construction caused by ageing. An elastomer (radial styrene butadiene styrene, SBS) and a plastomer (ethyl vinyl acetate, EVA) polymer were mixed with one base bitumen at three polymer concentrations. The bitumens were RTFO and PAV aged. The morphology of the bitumens was captured by fluorescence microscopy while the rheological properties were measured by means of the m…
Evaluating the safety of platooned heavy vehicles: A case study
2016
In the right lane of motorways with trucks' overtaking prohibition is very common the formation of platoons of heavy vehicles. Although this traffic controls strategies can increase the capacity of passing lane, in the right lane may occur increases of rear-end collisions. The purpose of this research was to evaluate the safety of the platooned heavy vehicles by means a closed-form stream model. The case study of the Italian motorway A22 was examined. The sampling of platoons was performed in four observation sections.In the research have been investigated platoons with 2/20 heavy vehicles for each platoon. Many traffic parameters have been evaluated: frequencies of the number of platoons, …
A model to evaluate heavy vehicle effect in motorway traffic flow
2017
Highway operating conditions are also determined by interactions between passenger cars and heavy vehicles in the flow. Therefore, a suitable model which describes and predicts the heavy vehicle effect can be useful to achieve more realistic criteria to evaluate the Level of Service (LOS) for infrastructures in the uninterrupted flow. After reviewing briefly the models available in literature to take account of the effects on operating conditions due to heavy vehicles, the paper examines some traffic data analysis of the Italian A22 motorway and later presents a closed-form traffic model for heavy vehicles via the queuing theory. Some applications of this model are displayed for operational…
Comparing Performances of Turbo-roundabouts and Double-lane Roundabouts
2012
Starting from assumptions regarding the arrival process of circulating streams and according to models based on the gap-acceptance theory, the paper is aimed at comparing operational performances between basic turbo-roundabouts and double-lane roundabouts. The paper proposes applications of the Hagring model for entry capacity estimations at double-lane roundabouts and turbo-roundabouts, these latter, in particular, featured by movements with only one or two conflicting traffic streams. This model allows to use, in fact, a bunched exponential distribution to quantify the distribution of major vehicle headways; it also considers specific values different by each lane for behavioural paramete…
La cultura delle vie di trasporto.
2010
Notiziario della SIIV su Le Strade N.1454, Gennaio/Febbraio 2010 (casa Ed. la fiaccola,Milano)-ISSN: 0373-2916.
ALTA FORMAZIONE ALLA RICERCA. A BRESCIA DAL 5 AL 9 SETTEMBRE, LA NONA EDIZIONE DELLA SCUOLA ESTIVA SIIV
2011
Pagina associativa della Società Italiana di Infrastrutture Viarie sulla rivista Le Strade vol.9 N. 1470 anno CXIII (casa Ed. la fiaccola, Milano)-ISSN: 0373-2916, PAG. 158
A scuola di grandi infrastrutture
2011
Pagina associativa della Società Italiana di Infrastrutture Viarie sulla rivista Le Strade vol.10 N. 1471 anno CXIII (casa Ed. la fiaccola,Milano)-ISSN: 0373-2916, PAG. 127
Traffic simulation models calibration using speed–density relationship: An automated procedure based on genetic algorithm
2016
Calibration of traffic models.Calibration as optimization problem.Use of genetic algorithm. This paper presents the first results of a research which applied a genetic algorithm to calibrate a microscopic traffic simulation model based on speed-density relationships. A large set of traffic data collected from the A22 Freeway, Italy, was used and a comparison was performed between the field measurements and the simulation outputs obtained for a test freeway segment by using the Aimsun microscopic simulator.The calibration was formulated as an optimization problem to be solved based on a genetic algorithm; the objective function was defined in order to minimize the differences between the sim…
A PSO algorithm for designing 3d highway alignments adopting polynomial solutions
2017
Intelligent optimization algorithms for highway alignments have produced good results so far. However, considering the numerous constraints and factors directly implied in the infrastructure design, the researchers' efforts usually focus only on simplifying the alignment choice, supporting engineers in the design phase. Implementing strategic considerations regarding comfort and safety would be also very important. In this paper, the authors propose a method for designing improved 3D highway alignments using a specific optimization algorithm, based on a Swarm Intelligence technique, adopting an innovative polynomial transition curve as the unique horizontal curvature element, called PPC (Po…