23 research outputs found
Planning urban pavement maintenance by a new interactive multiobjective optimization approach
No full textPavement maintenance is essential to prevent the deterioration of asset value and to satisfy the expectations of all stakeholders (objectives). However, the budgets are often insufficient to keep the road pavement at optimum levels. Therefore, a decision making process ought to be used for prioritizing different maintenance activities in order to achieve pre-defined goals by optimizing the use of the available budget. One of the biggest difficulties in multiobjective optimization method is the large number of the feasible solutions (Pareto optimal set or its approximation), which makes it hard for the Decision Maker to select the best solution.To support interaction with the decision maker for identifying the best combination of maintenance actions, this paper proposes a new methodology named Interactive Multiobjective Optimization-Dominance Rough Set Approach (IMO-DRSA), using a decision-rule preference model.The preference information, obtained by the Decision Maker (DM) during the course of the interaction, is processed using the Dominance-based Rough Set Approach in order to achieve a decision model expressed in terms of easily understandable if ....then ... decision rules. This approach makes possible an interaction between the analyst and the decision maker and helps the decision maker to classify maintenance options and allocate limited funds according to predefined objectives (quantitative or qualitative). An application of the proposed methodology to road pavements of an Italian urban sub-network is presented
Dominance-based rough set approach:An application case study for setting speed limits for vehicles in speed controlled zones
No full textSafety Index for evaluation of urban roundabouts
No full text: Recently, there is a growing interest in road safety assessments based on the examination of the characteristics of the road aimed at identifying the presence of risk factors. This approach, named road assessment program or network wide road safety assessment, is required by the EU Directive 2019/1936 on road infrastructure safety management. Reliable procedures for assessing the inherent safety of all the elements of the road network are required to conduct roadway safety assessments. To provide a contribution toward the development of procedures for network wide road safety assessment, this paper develops and validates a Safety Index (SI) for evaluating urban roundabouts. The SI is assessed both at the roundabout level as well as at the roundabout approach level. This procedure detects the safety issues that are the largest contributors to crash risk in order to identify the safety measures that provide the greatest crash reduction at roundabouts. The SI is formulated by combining two components: the exposure of road users to road hazards (Exposure) and the risk factors which increase the probability of involvement in crashes (Risk Index). The procedure considers 33 detailed safety issues and 5 general safety issues to compute the Risk Index. Criteria for identifying and ranking the safety issues are defined. The SI procedure was validated in a sample of 50 urban roundabouts located in Rome, Italy. The sample consisted of 12 single-lane roundabouts and 38 two-lane roundabouts, with a total number of approaches equal to 179. In these roundabouts, the SI scores and the EB crash estimates were compared with reference both to the whole roundabouts as well as to the single roundabout approaches. The correlation between the SI scores and EB estimates was highly significant both at the roundabout level (R2 = 0.85, t = 16.49, p-value < 0.001) as well as at the approach level (R2 = 0.56, t = 14.88, p-value < 0.001). The results from Spearman's rank-correlation analysis provided further validation for the SI indicating that rankings from the SI and the EB estimates agree at the 99.9 % confidence level both at the roundabout level (ρs = 0.80) as well as at the approach level (ρs = 0.70)
Advancing road safety in urban area: the impact of roundabouts on intersection design
No full textIntersection represents a significant challenge around road traffic safety, posing a major problem, and particularly during peak hour of urban road traffic. The high risk of accidents at this congested intersection is a serious concern, given that they involve a variety of road users, including vehicles and pedestrians. To address these challenges and minimize the risks related to intersections, roundabout have emerged as a significant effort. To address these challenges and minimize risks related to intersections, roundabouts have emerged as a notable solution. This approach does not only contribute to improved traffic flow but also enhances overall road safety by providing a more efficient alternative compared to conventional intersection designs. This study takes a comprehensive look at the safety performance of roundabouts as an alternative intersection design, by systematically reviewing relevant literature from Scopus and Google Scholar, aiming to explain how roundabout intersections contribute to crash reduction and traffic safety improvement. The analysis reveals that roundabouts generally lead to a significant reduction in severe collisions and enhance traffic flow efficiency. This is primarily due to their design, which minimizes conflict points and promotes lower vehicle speeds, and positively impacts the visibility and safety of pedestrian crossings. However, the roundabout has challenges, such as the requirement for drivers to adapt to new traffic patterns and the public’s perception of the different aspects of the roundabout design. The findings indicate that roundabouts substantially improve road safety, evidenced by significant reductions in fatal and injury crashes. The literature also emphasizes the importance of customizing roundabout design and implementation to specific conditions, highlighting that such adapting is critical to maximizing benefits and ensuring positive impacts on road safety which is important to developed in further research
A new methodological approach for road friction deterioration models development based on energetic road traffic characterization
No full textSafety studies have indicated strong correlation between road friction and accident risk, with a dramatic increase in accident when friction drops below certain threshold. For this reason, managing pavement skid resistance is an important mean to reduce crashes. Unfortunately, during the pavement lifespan, skid resistance undergoes to deterioration due to several factors (traffic wear, weathering and aging). The correct management of road pavements implies the knowledge of the performance evolution, obtained both with monitoring and degradation models, however, among those latter available in literature, very few explored the influence of traffic vehicles in terms of type and travel mode. In this paper a new methodology combining the use of road sectioning schemes with a traffic damage criterion based on the dissipated energy at the tire-road pavement contact, for the development of degradation curves from experimental data collected on roads with different traffic, in terms of volumes, vehicle composition and motion conditions, is presented. The methodology has been validated to an open graded bituminous surface course (OGSC) on urban motorway and obtained degradation models have been also compared with those provided by a traditional degradation modelling approach highlighting the superior performance of the proposed approach
Dal vestema al word design: modelli di lettura e d’analisi linguistico-testuale a confronto
No full textThe names of every garment and accessory contribute to give shape to the mental representation of our personal and collective identi-ties: how can we comprehend and “read” this code? The processes of mea-ning in fashion discourse are connected to each other and must be analyzed together in order to understand their true relevance into the cultural and creative relationships. It is known that Barthes has shown that the fashion system is structured on different levels. The vesteme is a fundamental con-cept of his theory about the fashion system. It is the result of the intersec-tion of eight different axes (materials, size, colours, etc.) and four kinds of signifier/signified combinations (Barthes 1967). The theory of the Word Design (Rak-Catricalà 2013; Catricalà-Guidi 2014) starts from this idea to overcome the structuralist and socio-semiotic point of view and to examine the language of fashion through a cognitive paradigm. The key idea is that the verbal profiling (Langacker 2002) of the garments constructs and, at the same time, changes our perceptions and their valence like vehicle of com-munication. The paper is divided into two parts. The first describes the de-scription of the traditional models (sociological, anthropological and psy-chological too) of classification of the fashion terms, between the needs of similarity (clothing) and dissimilarity (fashion). The second presents some examples of garments names analysis based on the Word Design Theory (WDT), i.e. a new interface between the texts and the lexicon and the rhe-toric figures. The instruction-words/actions, the description-words/analogy and the narration-words/metaphors outline various semantic and pragma-tic contexts and are linked to different types of environment and affordance
Evaluation of effective renal plasma flow with I-127 ortho-iodohippurate and I-123 ortho-iodohippurate in rabbits
No full textEconomic Risk Evaluation in Road Pavement Management
No full textPavement maintenance is essential to prevent the deterioration of asset value and satisfy all stakeholders' expectations. However, the budgets are often insufficient to keep the road pavement at optimum levels. Therefore, a decision-making process ought to be used to prioritize different maintenance activities to optimize the fulfillment of the pre-defined goals. At the same time, there is a growing need to integrate risk management into asset management, and therefore into the Pavement Management System. It is the best way to understand risk in decision-making at the program and organizational levels. This paper examines how risk-based pavement management practices can be implemented. The idea is to identify the best combination of maintenance actions given budget constraints, also considering budget risk reduction within a multiobjective optimization process. As far as economic risk assessment is concerned, probabilistic LCCA with Monte Carlo Simulation was used to investigate the risk of budget exceeding in Pavement Management Systems as a secondary criterion for choosing the optimal maintenance strategy on a road network. The method allows assessing epistemic uncertainties regarding discount rate and materials, man-power, transportation, and equipment rental costs. Outputs were able to show the possible variability of maintenance strategies costs. Moreover, probability density functions provide for establishing the most economically advantageous solutions (lower mean value) and for the riskiest ones (greater standard deviation). The optimal strategy might be selected by minimizing the probability of budget exceeding. The innovation of this research is in the introduction of the quantitative economic risk analyses into pavement management, with the aim to integrate epistemic and aleatory uncertainties in the process
