936 research outputs found

    A Decision Support System for the safety evaluation of urban pedestrian crossings

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    This paper proposes an innovative methodology, based on a Decision Support Systems, for the safety evaluation of pedestrian crossings without traffic lights in urban neighborhood areas. It provides an on-site inspection performed using ad-hoc data check lists, and it allows to assign a safety rate to the pedestrian crossing, in order to define a priority list of interventions and to suggest which features need to be improved. This new approach can be useful and easy to use for public administration managers and local governances, when they need to allocate limited financial resources to several pedestrian crossings. It has been applied to 10 pedestrian crossings on two roads in the urban area of Bologna and the resulted ranking list has been used by the Municipality of Bologna in its Urban Road Safety Plan 2016-201

    Rheological characterization of bituminous mastics containing waste bleaching clays

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    Bleaching clays are mostly used in food industries to clarify vegetal oils. After use they are generally dumped as waste (stage 1) or used in green innovative plants to feed biogas reactors (stage 2). In latter stage the initial residual oil content (ap-prox. 25% by mass) is reduced to less than 1% by the biological process. In this study the bleaching clays effects on bituminous mastics of a traditional binder course Hot Mix Asphalt have been investigated. The physical characteristics of the two bleaching clays and of a traditional limestone filler were also studied. DSR rheological tests at high and low temperatures were performed on mastics samples containing different amounts of fillers (limestone, stage 1 or stage 2). The addition of the different waste bleaching clays significantly affects the rheological behav-ior of the mastics: the filler from stage 2 increases the mastic stiffness improving the resistance to permanent deformations as shown by repeated creep tests, while the filler from stage 1 strongly interacts with the bitumen reducing the mechanical characteristics of the mastics at all temperatures

    Calcifediol Rather Than Cholecalciferol for a Patient Submitted to Malabsortive Bariatric Surgery: A Case Report

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    Vitamin D deficiency following malabsorptive bariatric surgery can lead to osteomalacia. We report a patient with severe vitamin D deficiency following malabsorptive bariatric surgery successfully treated with calcifediol but not cholecalciferol. A 40-year-old woman, submitted to biliopancreatic diversion 20 years before and chronically treated with 50,000 IU cholecalciferol weekly, was admitted to our Endocrine Unit because of severe lower back pain, muscle weakness, and generalized muscular hypotrophy, associated with hypocalcemia and elevated PTH levels. Initial evaluation revealed low serum albumin, low albumin-corrected serum calcium (7.36 mg/dL), high serum PTH (240 pg/mL), bone-specific alkaline phosphatase (125 ÎĽg/L) and 1,25-dihydroxyvitamin D (112 pg/mL) concentrations, undetectable serum 25-hydroxyvitamin D (<7 ng/mL), and evidence of reduced liver function. Bone mineral density was markedly low. Normocalcemia was initially restored with intravenous albumin and calcium gluconate. Treatment with calcitriol (0.5 ÎĽg three times daily) and oral calcium carbonate (1000 mg daily) was simultaneously started and cholecalciferol was replaced with calcifediol [125 ÎĽg (5000 IU) daily)]. During follow-up the calcifediol dose was progressively tapered to 25 ÎĽg (1000 IU) daily and the calcitriol dose was progressively reduced and finally withdrawn. Serum albumin and other biochemical parameters normalized, bone mineral density significantly increased, and the patient's clinical conditions progressively improved, with a substantial recovery of autonomy. Serum vitamin D binding protein at the last observation was in the normal range. Our data suggest that calcifediol might be more efficacious than cholecalciferol for prevention and treatment of vitamin D deficiency in patients treated by malabsorptive bariatric surgery

    How Do University Student Cyclists Ride? The Case of University of Bologna

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    In a general urban planning context, in which sustainable active mobility progressively takes up increasing attention, studies of cyclists’ attitudes and behaviors represent a relevant step to help any enhancing measures for urban cycling. Among different categories, university student cyclists represent a still unidentified class, despite the relevant impacts in terms of mass and variability of attitudes in urban areas. The novelty of this paper is to propose an innovative overview on the specific category of university student cyclists. The integrated methodology, based on direct observation through GPS detection, GIS processing, and qualitative survey, permits the evaluation of some interesting issues related to students’ propensity to cycling and their mobility patterns. The approach finds relevance in speed, frequency of movements, routing, and related infrastructure preferences. The methodology has been applied to a sample of more than 300 students of the University of Bologna who were allowed an original university-designed bicycle from February 2021 to June 2021. The analysis was applied in the Bologna urban area and allowed the evaluation of students’ preferences of using existing cycle paths, when available, the limited relevance of speed factors, the main distribution of commuter journeys concentrated in the main avenues directed to city center, and other behaviors

    Safety roads: the analysis of driving behaviour and the effects on the infrastructural design

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    Road design should ensure the correct behaviour of drivers in terms of speed and level of attention. Nevertheless, in some cases users are not able to visualize the carriageway enough correctly, owing to the misled road layout or the loss of visibility. In this research, road safety management was assessed with the driving and visual behaviour of users, considering the impact of different configurations of pedestrian crossings and road signs in order to reduce accidents. Even if users focus their attention on the zebra crossing (60%) and the vertical sign (24%), 16% of them have had no perception of the pedestrian crossings. This result shows how pedestrian crossings represent critical points that could compromise the safety of vulnerable users also in relation to speed. In fact, driving behaviour highlights 50 km/h of the average speed at 100 meters before the crosswalk, which allows having a too short time to stop the vehicle in safety. Moreover, the maximum speed underlines that users drive beyond the limit imposed by the road’s rules. It is thus necessary to require the implementation of road infrastructure so as to modify the driving behaviour. Starting from the Road Safety Review, it was then possible to detect the critical issues and correlate a visual and kinematic analysis so as to intervene accurately

    Road Safety Review update by using innovative technologies to investigate driver behaviour

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    International Congress on Transport Infrastructure and Systems in a changing world, Rome, ITALIE, 23-/09/2019 - 24/09/2019Urban arterial roads provide high-speed passage to facilitate traffic in urban areas. However, unlike freeways, they consist of ramps, roundabouts and unique characteristics due to the limited space in the urban (or semi-urban) environment. The existing studies use the Road Safety Review (RSR) to evaluate geometry, identifying high accident concentration sections and to classify the network based on expert judgment. Therefore the classical methodology does not consider the interaction between driver and infrastructure. The present study aims to investigate the road safety of an urban arterial motorway, integrating traditional checklist with innovative solutions applied in an experimental site test with participants. The driver visual behaviour has been recorded by head-mounted eye tracker that is used to find the gaze behaviour. The vehicle used for the test was equipped with the satellite positioning system (GPS), inertial measurement unit (IMU), vehicle CAN data reader (OBD2) and video recorder to monitor the driver behaviour and vehicle trajectory during the track. The results showed that the use of innovative techniques could improve the RSR, by identifying new hazardous points based on driver behavior

    Urban Regeneration and Soft Mobility: The Case Study of the Rimini Canal Port in Italy

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    The increasing need to reduce emissions and the environmental impact of urban areas to meet European decarbonisation goals motivates the selection of the Rimini Canal Port as a case study within the FRAMESPORT project, part of the European Interreg Italy–Croatia programme. A preliminary historical–documental and urban regulations analysis of the context allowed the identification of the main criticalities and potentials through a SWOT analysis. The central role of the stakeholders enabled the creation of a successful participatory co-design process developed through online surveys. Critical issues that emerged during the data collection phase were prioritised through a BOCR model, a powerful multi-criteria analysis tool. The project phase then focused on the resolution of the two main critical issues that emerged: the improvement of cycle/pedestrian paths, and the raising of the flooding docks in the Canal Port area. This article intends to demonstrate the strong influence of soft mobility in urban regeneration projects, and how an improvement of the quality of cycle/pedestrian paths can increase the quality of urban spaces. The new paths create a green infrastructure that contributes to a reduction in pollutant emissions through the promotion of sustainable mobility systems and an increase in green urban spaces

    Unveiling the Socio-Economic Fragility of a Major Urban Touristic Destination through Open Data and Airbnb Data: The Case Study of Bologna, Italy

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    In the last decades, tourism in urban areas has been constantly increasing. The need for short-term accommodations has been coupled with the emergence of internet-based services, which makes it easier to match demand (i.e., tourists) and supply (i.e., housing). As a new mass tourist destination, Bologna, Italy, has been experiencing tensions between tourists and long-, mid-, or short-term renters. The possibility of easy profits for lessees has led to an increase in such housing, which can be rented out either for touristic reasons or not. This paper aims to unveil the contribution of short-term rental accommodations in distorting the real estate market and conditioning social and economic inequalities. To do this, multiple linear regression analyses (MLR) were performed between accommodation density, real estate market information, and indicators about social, economic, and demographic vulnerability and fragility. Analyses were based on official open data and datasets from a major web-based hospitality exchange platform, i.e., Airbnb, able to provide information on registered accommodations, e.g., type, characteristics (e.g., number of bedrooms and average rating), and location. Outputs of the analyses reveal the role of Airbnb in both rental market and social, economic, and demographic vulnerability and fragility and, hence, can be a solid tool for public policies, both housing- and tourism-related

    Driver's visual attention to different categories of roadside advertising signs

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    Roadside advertising signs are a salient potential source of driver's distraction. Previous research has mainly investigated driver's visual attention to billboards, which represents only one category of advertising signs. In this study, driver's visual attention was assessed in a naturalistic driving setting for six categories of roadside advertising signs: vendor signs, billboards, movable display boards, single and multiple commercial directional signs, and gas price LED displays. Fixation rate, fixation duration, fixation distance and driving speed were assessed in a sample of 15 drivers along a 30-km route including a total of 154 advertising signs belonging to the six categories described above. The role of clearance from the road, elevation, height, width, surface, number and size of characters, total number of characters, side of the road (driving side, opposite side), context (rural, urban), were also considered. Overall 24% of the roadside advertising signs were fixated. Fixation rate was significantly influenced by sign category, clearance from the road and number of characters. Median value for fixation duration was 297 ms. Fixation duration was significantly influenced by speed, elevation from road level, number of medium size characters, and was higher in the rural context. Median value for fixation distance was 58.10 m, and was significantly influenced by advertising sign category, character count and speed

    Road users’ behaviour in the "30 km/h zones". The case study of Bologna

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    Excessive vehicle speeds in urban areas have resulted to be a major cause of road accidents involving pedestrians, cyclists, and motorcyclists, identified as "vulnerable road users" (VRU). A possible useful strategy to overcome this problem, both reducing speed and safeguarding vulnerable road users (VRU), is the introduction of "30 km/h zones". As traffic calming measures, they allow a maximum speed for drivers of 30km/h. The purpose of this study is to monitor the behaviour of drivers in the “30 km/h zones” of the centre of Bologna. With the close collaboration of Bologna Municipality, the study has provided for the monitoring of speed and type of transport in specific points within a selected circuit. Data collected showed that, although in most of the selected zones, speeds are below 30 km/h, in the areas where traffic is heavier, drivers exceed the permitted limit
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