30 research outputs found
Blending of Floating Car Data and Point-Based Sensor Data to Deduce Operating Speeds under Different Traffic Flow Conditions
Nowadays, smart mobility can rely on innovative tools for the knowledge of road system conditions, like operating speed data extracted from the so-called Floating Car Data (FCD). Probe vehicles in the traffic flow send to operation centres a large amount of travel information, collected through GPS detection systems, especially with regard to geolocation, date and time, direction and speed. As the sample deriving from these vehicles represents a tiny portion of the entire vehicular fleet, in this paper an analysis and a comparison with data obtained by point-based traffic sensors is proposed.Therefore, the study analyses data collected by inductive loop detectors and microwave radar sensors, that provide information on the entire traffic flow in the time domain, in particular with the aim to identify free flow speed time bands. Afterwards, by means of the fusion between the results obtained from the data coming from these point-based control units and the ones coming from the probe vehicles, a comparison of the operating speeds in the two conditions of constrained and unconstrained traffic flow is performed
Speed data collection methods: a review
Various studies have been focusing on a wide range of techniques to detect traffic flow characteristics, like speed and travel times. Therefore, a key aspect to obtain statistically significant set of data is to observe and record driver behaviours in real world. To collect traffic data, traditional methods of traffic measurement - such as detection stations, radar guns or video cameras - have been used over the years. Other innovative methods refer to probe vehicles equipped with GPS devices and/or cameras, which allow continuous surveys along the entire road route. While point-based devices provide information of the entire flow, just in the section in which they are installed and only in the time domain, probe vehicles data are referred both to temporal and space domains but ignore traffic conditions. Obviously, it is necessary that the data collected refer to representative samples, by number and composition, of the user population. The paper proposes a review of the most used methods for speed data collection, highlighting the advantages and disadvantages of each experimental approach. Accordingly, the comparison illustrates the best relief method to be adopted depending on the research and investigation that will be performed
Effectiveness of Climbing Lanes for Slow-Moving Vehicles When Riding Uphill: A Microsimulation Study
Long uphill stretches of single-carriageway rural roads with one lane per travel direction may reduce the Level of Service (LoS), due to the decreased speed of heavy vehicles. In those circumstances, a slowdown of traffic, resulting in the formation of platoons, may be generated due to the difficulty of performing overtaking maneuvers safely. To solve this critical issue, an additional (climbing) lane for slow vehicles may be included in the road platform. This study aims to evaluate the effectiveness of such climbing lanes in a real case in Italy (National Road n. 4 “Via Salaria”— around 44+000 km). Using a microsimulation model implemented in VISSIM, the study analyzes speeds and travel times, delays, and queuing waiting times, comparing the Actual Scenario (AS) without climbing lanes, with two counterfactual scenarios: the first one (CS1) with three stretches of climbing lanes, and the second one (CS2), with just two stretches, in which the first two additional lanes of CS1 are merged together. The obtained results confirm the effectiveness of installing climbing lanes on road sections with the described characteristics, and the potential of microsimulation models also to carry out such kind of evaluations
Road Infrastructure Safety Management. Proactive Safety Tools to Evaluate Potential Conditions of Risk
The identification of highly critical sections in a road network is possible by examining the network operation, with the goal of determining the risk factors and observe the critical issues, in order to better plan possible improvements. Therefore, this study proposes a method to evaluate the coherence of existing road layouts, through the analysis of the geometric characteristics, theoretical speeds and drivers operating speeds, under different environmental and flow conditions. The analysis focuses on the road network managed by ANAS SpA in the Veneto Region, for which the reconstruction of the road axes geometry, the curvature graph and the theoretical design speed profile have been obtained, according to the indications of the Italian Ministerial Decree 05/11/2001. The theoretical design speed profile has then been compared with the information relating to the road users' mobility, in terms of the 85th percentile speeds, obtained from the extraction and analysis of the Floating Car Data (FCD). The data were processed by reconstructing the continuous profile of operating speeds with a specific regression function known as "smoothing cubic spline". The comparison with the theoretical design speeds allows to observe whether the users assume a behavior close to or distant from what is expected, based on the technical and geometrical characteristics of the road layout. The proposed methodology can contribute to the implementation of a proactive road safety check, aimed at recognizing and assessing the potential risk conditions for road traffic, with particular attention to the point of view of the road user
A Small Robot to Repair Asphalt Road Potholes
As part of the Horizon 2020 InfraROB project aimed at enhancing road safety through innovative robotic solutions, a compact autonomous vehicle has been developed to repair asphalt potholes. Central to this system is a 3D printer capable of extruding a novel cold-asphalt mixture, specifically designed for patching road surfaces. The printer is mounted on a small robot that autonomously navigates to potholes, while the human operator controls the operation from a secure location outside the traffic area. The system's development involved several key steps: designing the repair mixture, constructing the 3D printer for mixture extrusion, implementing a photogrammetric technique to accurately measure pothole geometry for printing, and integrating the extrusion system with the robotic platform. Two preliminary tests were conducted in controlled environments at Sapienza University of Rome to check the reliability of calculation of the amount of material needed to fill in the potholes. Finally, the entire procedure was tested on an Italian motorway, demonstrating the system's functionality without encountering operational issues
Efficacy and Safety of Neem Oil for the Topical Treatment of Bloodsucking Lice Linognathus stenopsis in Goats under Field Conditions
The aim of the present study was to evaluate the efficacy and safety of neem oil on caprine pediculosis and on kids’ growth performances. The neem (Azadirachta indica) belongs to the Meliaceae family, and in Eastern countries it is mainly considered for the insecticidal activities of the kernel oil. The neem seeds contain bioactive principles, such as azadirachtin A, salannin, nimbin, and nimbolide. The trial was carried out on 24 kids, 120 days old, maintained in open yards. Animals were divided in 4 homogeneous groups (n = 6 animals/group) based on age, louse count, body condition score (BCS) and live body weight: Control Group (C, saline NaCl, 0.9%), Neem Group 1 (NO-100, 100 mL of neem oil per 10 kg), Neem Group 2 (NO-200, 200 mL/10 kg), Neem Group 3 (NO-300, 300 mL/10 kg). The treatments were performed by spraying the insecticide on the goat’s body. The study lasted 56 days, and weekly, the kids underwent louse count, BCS and body weight determination, and FAMACHA score. Data were analyzed by ANOVA for repeated measures. The species of lice identified was Linognathus stenopsis. Kids belonging to NO-200 and NO-300 showed a stronger reduction of louse count throughout the study (>95%). The daily weight gain recorded was significantly higher (p < 0.05) in NO-300 than C. No differences were found for BCS and FAMACHA scores. The results of this trial showed that the administration of neem oil to control caprine pediculosis caused by sucking lice represents an alternative to synthetic compounds
Cradle-to-cradle life cycle assessment of railway prestressed concrete sleepers: A state-of-the-art review and strategies for reducing environmental impacts
The construction sector, responsible for 39 % of global CO2 emissions, requires innovative solutions to reduce its environmental footprint. This study presents a "cradle-to-cradle" life cycle assessment (LCA) of prestressed concrete railway sleepers, following EN 15804:2012 + A2:2019, to quantify and mitigate their environmental impacts. It covers production, installation, use, maintenance, dismantling, and potential reuse, recovery, and recycling benefits. The product stage contributes 79 % of total environmental impacts, primarily driven by cement (50 %) and steel (49 %). Proposed strategies, including the use of recycled materials and alternative transportation methods, achieve an 18 % reduction in greenhouse gas (GHG) emissions, a 30 % decrease in nonrenewable energy consumption, and a 50 % reduction in ozone depletion potential. Key contributions to these reductions come from replacing traditional cement with clinker derived from solid fuels and shifting sleeper transportation from road to rail, highlighting the critical role of sustainable practices in advancing the environmental performance of railway infrastructure
A stepwise regression to identify relevant variables affecting the environmental impacts of clinker production
The construction sector contributes to 8% of carbon dioxide emissions, most of them caused by clinker production: in recent years, the efforts to reduce environmental impacts are growing. This paper investigates the environmental performances of clinker production and the factors driving emissions. For this purpose, the environmental impacts of 41 different grey clinkers produced in Italy from 2016 to 2021 certified by a third party according to the European standard EN 15804 have been assessed. Three input datasets (i.e., energy consumption, raw materials, and transport) have been investigated to identify the most significant variables that affected the environmental impact categories in the period 2016–2020: a stepwise regression allowed the identification of the optimal predictors to be included in the multiple regression models. The most significant variables are pet coke, fossil fuels, natural raw materials, and lorry transport. The identified models have been validated having regard to 2021 data. Therefore, for each impact category, multiple positive and negative dependencies which bear an effect on the environmental results have been quantified. The output provides proven quantitative results that can support cement producers to develop low-impacting clinker recipes
Analisi “dalla culla al cancello con opzioni” di traverse ferroviarie in calcestruzzo // “Cradle to gate with options” analysis of railway concrete sleepers
The transportation sector is responsible for about 25% of greenhouse gases and plays a pivotal role in countering global warming and emissions to the air. Railway is the most efficient transport system due to its low emissions per transport unit for freights and passengers. However, it is meaningful to assess the impacts of the infrastructure itself at the Product Stage, Construction Process Stage, and End of Life Stage. This study assesses the environmental impact of the production, installation, and dismantling of one 230 VN prestressed concrete railway sleeper with fastening system. The methodology used is the Life Cycle Assessment - LCA according to the standard UNI EN 15804:2012 + A2:2019. The examined life cycle involves the emission of 83 kg of CO2 eq. whose 10% is from the Construction Process Stage. Raw materials extraction, electricity production, and road transportation contribute 92%, 3%, and 5% to climate-altering impacts of the Product stage. The results highlight the variables to be addressed to increase the sustainability of the rail transportation system