Search results for "Freeway"
showing 10 items of 11 documents
Speed Stochastic Processes and Freeway Reliability Estimation: Evidence from the A22 Freeway, Italy
2013
In this paper, a criterion for predicting the reliability of freeway traffic flow is presented. The idea is based on an analysis of spot speed time series divided into sequences of events of random and homogeneous traffic processes. For each process, the flow rate and density were calculated; then the relationships between parameters of spot speed processes and vehicular density were obtained. Using these relationships and a simulation procedure for the spot speed process, a formulation for predicting the reliability of traffic flow moving along the offside lane on the freeway roadway was derived. Through this formulation and the measurements of flow rate and speed, the probability of insta…
Developing Passenger Car Equivalents for Freeways by Microsimulation
2015
Abstract In this paper a method of estimation of the passenger car equivalents for heavy vehicles on freeway is described. The variation in traffic quality was evaluated basing on a traffic demand characterized by different percentages of heavy vehicles. Aimsun micro-simulator was used to isolate traffic conditions difficult to capture on field, to replicate them to have a number of data as much as possible numerous, and to quantify the fundamental variables of traffic flow, namely the speed, flow, density, for a test freeway segment. Model calibration was accomplished by using traffic data collected at observation sections on the A22 Brenner Freeway, Italy. In order to check to what extent…
Superstrade urbane. Dall’alta velocità alle trasformazioni contemporanee
2013
This article focuses on urban freeway deconstruction processes that recognize this infrastructure as a resource to be reclaimed for urban regeneration. Since they first appeared, freeways have been more than simple carriers of traffic flow. Following the suggestions provided by Le Corbusier, Drexler and Rudofsky in their “ROADS” exhibition, Lawrence Halprin, Reyner Banham, particular attention is paid to the shift towards a larger set of aesthetic assumptions applied to highways. Fifty years after the iconic evocation of Autopia, urban freeways no longer embody the modern value of speed: they must increasingly deal with ecological challenges and re-cycling processes. The nodes where infrast…
ARCHITETTURA, CUSTODE DELLA NATURA : il progetto di suolo nella trasformazione delle autostrade urbane, 1962-2018
2023
Un inarrestabile cambiamento nel paradigma con cui l’uomo concepisce la propria specie rispetto ai suoi modi di costruire è alla base dell’attrattiva per l’incorporazione del vegetale nell’Architettura. Lo statuto euristico di maggiore capacità di tale nuovo corso è la sostituzione progressiva dell’Ambiente alla Natura fra i motori della Composizione. Su questo sfondo, l’articolo indaga l’ibridazione del vegetale e del costruito nella trasformazione contemporanea delle grandi autostrade urbane, attraverso un approccio diacronico e comparativo, in riferimento a una ricerca internazionale di cui estende l’ipotesi principale. A tal fine, ricostruisce il telaio ermeneutico di riferimento discut…
Calibration of Speed-Density Relationships for Freeways in Aimsun
2014
The first application of a calibration methodology which uses speed-density relationships in the microsimulation calibration process is described in this article. Traffic patterns were implemented developing speed-density relationships for empirical and simulated data. For empirical relationships reference was made to traffic data observed at A22 Freeway (Italy). Aimsun microscopic traffic simulator software was then used to obtain analogous relationships for a test freeway segment under uncongested traffic conditions. Thus on field conditions were reproduced varying some calibration parameters until a good matching between field and simulation was achieved. The closeness between empirical …
Autopia revisited
2013
Contro modello sin dalla loro prima apparizione, superstrade e circonvallazioni, attraversando il tessuto come barriere o trincee, hanno accresciuto in modo determinante il numero di figure urbane della discontinuità prodotto nel secolo XX dalla relazione di infrastrutture e città. Oggi, in relazione ai nuovi scenari della sostenibilità e della decrescita, si moltiplicano i processi di rigenerazione urbana che vedono queste infrastrutture come nuove, straordinarie risorse. Negli anni ’70, la trasformazione dell’Harbor Drive Freeway di Portland in un waterfront park di 1500 ettari fu un progetto pioniere, comparabile per dimensioni a quello dell’interramento del Big Dig – la Central Artery -…
Esperienza della didattica. Architettura e infrastruttura nella città contemporanea
2014
Il testo riguarda il metodo i temi e gli esiti del laboratorio di quarto anno di progettazione architettonica, che pone l’architettura fra le produzioni culturali complesse della nostra società, nel passaggio da un’idea di crescita quantitativa a un principio di crescita qualitativa, che includa l’ipotesi della decrescita, l’integrazione degli scenari di sviluppo con le proiezioni dei limiti e della sostenibilità delle trasformazioni. Il laboratorio chiede di elaborare il progetto di edifici di servizio e di una piazza in prossimità di uno svincolo dell’autostrada urbana e su alcune aree che lambiscono la circonvallazione di Palermo. Queste aree hanno caratteri di valenza generale, oggi ric…
Application of a genetic algorithm in calibration of traffic microsimulation models
2017
This chapter describes the genetic algorithm-based calibration procedure for a microscopic traffic simulation model focusing on freeways and modern roundabouts. For both case studies, the genetic algorithm tool in MATLAB® was applied in order to reach the convergence between the outputs from Aimsun microscopic simulator and the observed data. The automatic interaction with Aimsun software was implemented through an original external Python script. Results showed that the genetic algorithm-based calibration procedure gave a better match to the observed data than simple manual calibration and the efficiency of the calibration efforts resulted significantly improved. At last, the calbrated mod…
A statistical approach for calibrating a microsimulation model for freeways
2014
In this paper the calibration of a traffic microsimulation model based on speed-density relationships is presented. Hypothesis test was applied in the calibration process to measure the closeness between empirical data and simulation outputs and determine whether the difference between (observed and simulated) speed-density relationships was statistically significant. Statistical regressions between the variables of traffic flow were developed by using traffic data observed at the A22 Brenner Freeway, Italy. Similar relationships were obtained for a test freeway segment in uncongested conditions of traffic flow by using the Aimsun microscopic simulator; thus on field conditions were reprodu…
Re-Urban | De-frag. Progetti per trasformare la circonvallazione di Palermo
2014
This article presents a short survey of contemporary approaches to re-cycling, up-cycling and recovering urban freeways. Further, it introduces the assumptions and some initial descriptions of cases study of the Degree studio "In-FRA. Architettura e infrastruttura nella città contemporanea", that Z. Tesoriere conducts since 2013 at the University of Palermo. The studio focuses on how enhancing architectural conditions of urban freeways in contemporary urban realm, with particular attention to the circonvallazione of Palermo.