1,720,980 research outputs found
Considerazioni sull'opportunità di ulteriori sperimentazioni nelle gallerie ferroviarie per l'esercizio ad alta velocità
No full textRecent experiments allow to define aerodinamic effects of high speed trains in tunnels. On this ground it is possible to define the aims of another series of experiments in order to determine the functional relationship between some variables, which are to be fixed during the project, and some relevant physical quantities. At the present time it is possible only to create some suppositions about these functions but it appears evident the necessity of a quantitative analysis to be done as soon as possible in order to plan tunnels correctly
An experiment of an Urban Traffic Pollution Control System
No full textIn most of the European city centres, traffic congestion, air pollution and noise have become serious problems, leading to a significant effort in the search for new technical solutions. Within this framework, the paper deals with the relations between urban traffic flows management and environmental issues such as traffic noise and air pollution.
A research project, called “Application of ITS technologies for urban traffic control respecting environmental bounds”, has been carried out, whose final goal is the experimental evaluation of the effectiveness of a simultaneous traffic and pollution control in a middle-size Italian town.
The paper describes a work in progress within the research project, focusing on the practical experience which has been realised in the city of Trieste, a middle-size town in the North-East of Italy. In particular most attention is paid on the specific measurement device which has been specifically designed and built to provide a continuous measure of pollution in the analysed urban area.
This system may be integrated with the Urban Traffic Control System (UTCS), thus realising an urban traffic pollution control system which is now in an advanced phase of implementation
A MESOSCOPIC APPROACH TO CAPACITY AND DELAYS EVALUATIONIN UN-SIGNALISED ROUNDABOUTS
No full textThe paper refers to the estimation of roundabout’s performances. The evaluation of un-signalised intersections and in particular the evaluation of the multi-junction ones is actually a very troublesome task. The Department of Civil Engineering of the University of Trieste has proposed a methodology to dynamically estimate the merge-area capacity for on-ramp freeway junctions.
The evaluation of roundabouts is, at now, an open problem; many approaches have faced the problem of entry capacity and delays estimation, but a common and universally accepted procedure does not exist.
Some suggestions recently developed on the scientific literature have stressed on a specific point: a roundabout has neither to be considered nor modelled as a simple succession of T-intersections. On congested facilities or under very unbalanced flows, a roundabout should be considered as a multi-junction node. In addition, the facility has to be considered as a multi-junction node also because of the particular relationship between the entering and the circulating flows; in fact, the vehicles which could enter into
the roundabout depend on the circulating ones, which are the result of entered vehicles in the previous entry legs: the solution of this problem needs an iterative process but a final equilibrium solution could be found out
Specificazione e calibrazione di un modello di ripartizione modale per la mobilità extraurbana delle persone
No full textA traffic flow model for a monitoring and control system in the case of pay-toll freeways
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La distribuzione delle velocità nel flusso autostradale: elemento indicatore del differente comportamento dell'utenza nei modelli di previsione a breve termine
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