Search results for "Strade"
showing 10 items of 396 documents
Automated highway systems and hard-shoulders running: A case study
2016
The purpose of this research was to evaluate the increase of capacity of existing motorway resulting from the implementation of relatively new traffic control strategies, as the automated highway systems (AHS) and the hard-shoulder running (HSR). Was examined the Italian motorway A22, belonging to Trans-European Road Network, corridor Helsinki - La Valletta. Many traffic surveys were done (year 2014) in several road sections. For each of them have been carried out the flow diagrams, the traffic flow parameters (capacity C, free flow speed vf,jam density kjam) and the relationship between flow rate of lane (right lane Qright and passing lane Qpass) and total flow rate Qt. The current carriag…
Modeling traffic safety at urban four leg-signalized intersections
2013
According to the state-of-the-art of the methodologies, the development of safety performance functions (SPFs) for road sections and intersections requires the employment of statistical models to predict expected crash frequencies on the basis of traffic volumes and site characteristics to be surveyed and used as input to models. Nevertheless, literature reports several studies on issues deriving from data features or methodological approaches that may invalidate the efficiency of the models and the accuracy of the estimates. Drawing inspiration from the above mentioned considerations, the objective of this study is to develop safety performance functions for a sample of urban four leg-sign…
Performance Analysis of Basic Turbo-Roundabouts in Urban Context
2012
AbstractA turbo roundabout is a new type of canalized multilane intersection in which the physical separation between lanes helps to prevent side collisions when crossing the roundabout. This paper presents an estimation of capacity, delays and level of service of basic turbo roundabouts in undersaturation conditions, considering both vehicle flow and pedestrian traffic. The traffic performance model was developed by evaluating the capacity for each entry lane. Owing to the geometric features of the intersection, the total entry capacity is obtained by considering different values of the pedestrian impedance factor and degree of saturation at both the right-turn and left-turn lanes.
Piezoelectric energy harvesting from raised crosswalk devices
2015
This paper presents the main characteristics of an experimental energy harvesting device that can be used to recover energy from the vehicular and pedestrian traffic. The use of a piezoelectric bender devices leads to a innovative approach to Henergy Harvesting. The study focuses on the definition and specification of a mechanical configuration able to transfer the vibration from the main box to the piezoelectric transducer. The piezoelectric devices tested is the commonly used monolithic piezoceramic material lead-zirconate-titanate (PZT). The experimental results estimate the efficiency of this device tested and identify the feasibility of their use in real world applications. The results…
Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
2016
Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…
Estimation of air pollutant emissions in flower roundabouts and in conventional roundabouts
2013
Abstract The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the flower roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the capacity, delay, levels of service and the pollutant emissions into flower roundabouts. A comparative analysis between conven…
Time reduction for completion of a civil engineering construction using fuzzy clustering techniques
2017
In the civil engineering field, there are usually unexpected troubles that can cause delays during execution. This situation involves numerous variables (resource number, execution time, costs, working area availability, etc.), mutually dependent, that complicate the definition of the problem analytical model and the related resolution. Consequently, the decision-maker may avoid rational methods to define the activities that could be conveniently modified, relying only on his personal experience or experts’ advices. In order to improve this kind of decision from an objective point of view, the authors analysed the operation correction using a data mining technique, called Fuzzy Clustering. …
Methodological frontier in operational analysis for roundabouts: a review
2016
Several studies and researches have shown that modern roundabouts are safe and effective as engineering countermeasures for traffic calming, and they are now widely used worldwide. The increasing use of roundabouts and, more recently, turbo and flower roundabouts, has induced a great variety of experiences in the field of intersection design, traffic safety, and capacity modeling. As for unsignalized intersections, which represent the starting point to extend knowledge about the operational analysis to roundabouts, the general situation in capacity estimation is still characterized by the discussion between gap acceptance models and empirical regression models. However, capacity modeling mu…
Rolling resistance contribution to a road pavement life cycle carbon footprint analysis
2016
Purpose Although the impact of road pavement surface condition on rolling resistance has been included in the life cycle assessment (LCA) framework of several studies in the last years, there is still a high level of uncertainty concerning the methodological assumptions and the parameters that can affect the results. In order to adopt pavement carbon footprint/LCA as a decision-making tool, it is necessary to explore the impact of the chosen methods and assumptions on the LCA results. Methods This paper provides a review of the main models describing the impact of the pavement surface properties on vehicle fuel consumption and analyses the influence of the methodological assumptions related…
Towards more sustainable airfield pavements using life-cycle assessment of design alternatives
2020
Airports are critical infrastructures and their success is paramount to development through tourism, trade and connectivity. Within the airport, the runway pavement must always be in a pristine condition. Consequently, pavement design and maintenance decisions are vital. Authorities must make decisions concerning preferred materials for design and maintenance. Decisions should be balanced by both economic and environmental factors. This paper considers a case study at Falcone Borsellino Airport (PMO), Palermo, Italy, where air traffic has been steadily increasing. Different pavements are proposed: flexible Asphaltic concrete designs with both traditional Asphaltic concrete and using reclaim…