1,720,970 research outputs found
Analysis of weaving maneuver’s critical issues using a driving simulator
No full textIt is well known that the weaving maneuver is one of the most difficult maneuvers to analyze in terms of road safety. Weaving sections provide a transition for vehicles from the right lane to the left lane and from the left lane to the right lane; in order to allow drivers to enter a road stretch or to exit out of it. Interchange segments are the most likely area where road accidents occur because of the complexity of the weaving maneuver. The complexity of this operation depends on drivers’ behavior and risk perception associated with the different phases that compose the maneuver: the intensity changing lanes, and braking and accelerating behaviors of a driver under different traffic flow conditions. Using an interactive driving simulator, this study proposes an analysis of drivers’ behavior on different weaving lanes in various traffic conditions. Three different lengths of weaving lane combined with four different traffic flow conditions were simulated and the different drivers’ performances have been analyzed. The objective of the research is to evaluate reliable indicators able to verify weaving maneuver's safety standards, in order to achieve more efficient design criteria. Several findings have shown that a driving simulator can ensure the reliability of measures and, it can also show the relationships between road geometrical characteristics and drivers’ behavior
Analysis of accident rate prediction in overtake maneuvers: an hazard analysis application
No full textAccident data bases show that the overtake maneuver is one of the most frequent risky event. The aim of this paper is to define a methodology able to assess the risk connected with this maneuver along a road segment under different operating condition.
Referring to the risk theory and using probabilities calculated through the "tree of events", this study develops an innovative method for road accidents predictive estimation. The hazard analysis has been applied since able to keep into account of the sequence of the physical situation and the decisions taken by the drivers. These evaluations have been performed in CRISS (Inter University Research Center for Road Safety - Roma TRE University) laboratory with a driving virtual simulator which allowed to evaluate a key variable for estimating accidents risk under different conditions: the driver's behaviour in terms of ordinary prudence. In case of overtake maneuvers it has been built the “tree of events” and it has been defined the algorithms to calculate the probability of each “final event”.
The model has been calibrated analyzing accidents data base along homogeneous road sections. The analysis has been carried out for a total length of 800 km. All the sections have been organized into four groups characterized for functionality and geometrical properties. The results show good convergence between observed and calculated values. The results of this predictive model are more precise as the homogeneity of the road sections increase
Metodologie e strumenti per la stima degli effetti delle mitigazioni sul cambiamento climatico
No full textSafety Audit for Weaving Maneuver: A Driver Simulation Safety Analysis
No full textWeaving lanes are designed to ensure the crossing of two or more traffic streams traveling in the same direction along stretch of road without the aid of traffic control devices. Weaving lanes assume a key role in roundabouts characterized by wide inscribed circle diameter, where the weaving maneuver represents a crucial aspect for safety. This is confirmed by several findings that demonstrate as the weaving maneuver is one of the most difficult operation to analyze in terms of road safety. Many studies report that the combination between the length of weaving lanes and the traffic volume is a key factor to explain high accident rate along interchange zones. Bearing in mind this facet, this article proposes an analysis of driver behavior on different weaving lanes in various traffic conditions performed on an interactive driving simulator. Different lengths of weaving lane combined with different traffic flow conditions were simulated, and the different drivers' performance have been analyzed. A risk assessment has been conducted by analyzing driver's behavior as a function of driver's risk perception. It has been observed that the increase of weaving lane length is effective only when the traffic flow conditions exceed a certain threshold
Influence of highway traffic flow condition on pollutant emissions of diesel passenger cars using driving simulator
No full textIn the last 20 years the attention of international organizations towards air pollution has been improved, leading to definition of laws and regulations. In order to evaluate strategies and policies, forecasting tools have been adopted by institutions. Currently, the estimation of traffic emissions is based on static models, in which the amount of pollutant is computed as a function of average parameters (average speed).
The well-known traffic increase of the recent years has significantly changed the actual flow conditions, producing a strong rise of interferences. As this facet affects the operating condition of each vehicle, the use of a standard emission model at high traffic interference can lead to some inaccuracies. In such cases, instantaneous emission models introduce deeper capabilities; essentially, the pollutant prediction is directly tied to the engine vehicle operation point in real-like traffic condition. This second modeling approach has been adopted in the current work. A complete lumped parameter vehicle model has been built to be used as a virtual on-road emission/fuel consumption test unit. Investigations have highlighted the dependence of emission level and fuel consumption on drivers’ behavior; indeed, the analysis took advantage of the experiments carried out in the virtual reality laboratory: on a typical highway geometry, three different flow conditions have been simulated. In the present study has been highlighted the relationship between drivers behavior and the emissions of a diesel compact passenger car. Finally, in order to assess the differences between static and instantaneous emission models, a comparative analysis has been carried out
Traffic emissions estimation along a road infrastructure using a driver simulator
No full textIt is well known that traffic has increased in the last years. This phenomenon has significantly changed traffic :flow conditions
and has produced a significant increase of interferences. Because of this, it is more effective using emission data calculated
point by point instead of average values. In order to gencralize tbc phenomenon of emissions, tbc analysis took advantage of
the cxperiments carried out in the virtual rcality laboratory. This research takcs into account two diffcrcnt geomctries and for
each geometry, three different flow conditions. Data recorded using tbc driving simnlator will be compared with data obtained
from realscale tests
L’uso di strumenti di guida simulata per il calcolo delle emissioni di un’infrastruttura viaria
No full textThe Effects Of Traffic Flow Conditions On The Pollutants Emissions: A Driving Simulator Study
No full text"In the last 20 years the attention of international organizations towards air pollution has been improved, leading to definition of laws and regulations. In order to evaluate strategies and policies, forecasting tools have been adopted by institutions. Mainly, two groups of emission models are available: the former is represented by the static or “standard” models, in which the amount of pollutant is computed as a function of average parameters; the latter is represented by the dynamic models, where the amount of pollutant is computed as a function of instantaneous parameter, such as instantaneous speed or acceleration. . The well-known traffic increase of the recent years has significantly changed the actual flow conditions, producing a strong rise of interferences. As this facet affects the operating condition of each vehicle, the use of a standard emission models at high traffic interference can lead to some inaccuracies. In such cases, instantaneous emission models introduce deeper capabilities; essentially, the pollutant prediction is directly tied to the engine vehicle operation point in real-like traffic condition. However, this approach requires a large amount of input data (i.e. video recordings or remote sensing analysis), which are not always available. . In order to overtake such a difficulty, the present study is based on an integrated simulation tool. Emissions from road traffic are simulated through a dynamic model, whose input data are obtained by the output of virtual reality simulation. Indeed, the analysis took advantage of the experiments carried out in the vehicle virtual reality laboratory: on a typical highway geometry, three different flow conditions have been simulated. . Investigations have highlighted the dependence of emission level and fuel consumption on drivers’ behavior. The comparison between a gasoline and a diesel compact passenger car in terms of pollutant emissions and fuel consumption has been also reported. In order to assess the differences between static and instantaneous emission models, a comparative analysis has been carried out..
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