Search Results (40)

Tunnels are commonly found in small and enclosed environments on highways, roads, or city streets. They are constructed to pass through mountains or beneath crowded urban areas. To prevent accidents in these confined environments, lane changes, slow driving, or speeding are prohibited on single- or multi-lane one-way roads. We developed a foreground detection algorithm based on the K-nearest neighbor (KNN) and Gaussian mixture model and 400 collected images. The KNN was used to gather the first 200 image data, which were processed to remove differences and estimate a high-quality background. Once the background was obtained, new images were extracted without the background image to extract the vehicle’s foreground. The background image was processed using Canny edge detection and the Hough transform to calculate road lines. At the same time, the oriented FAST and rotated BRIEF (ORB) algorithm was employed to track vehicles in the foreground image and determine positions and lane deviations. This method enables the calculation of traffic flow and abnormal movements. We accelerated image processing using xfOpenCV on the PYNQ-Z2 and FPGA Xilinx platforms. The developed algorithm does not require pre-labeled training models and can be used during the daytime to automatically collect the required footage. For real-time monitoring, the proposed algorithm increases the computation speed ten times compared with YOLO-v2-tiny. Additionally, it uses less than 1% of YOLO’s storage space. The proposed algorithm operates stably on the PYNQ-Z2 platform with existing surveillance cameras, without additional hardware setup. These advantages make the system more appropriate for smart traffic management than the existing framework. Full article

Traffic calming measures are implemented more and more often in residential districts as part of home zone sustainability projects. For economic reasons, road humps are the most commonly used traffic calming measures to slow down the traffic within the home zone. Prefabricated units or concrete pavers are the materials of choice for their construction. The studies carried out so far on many different road hump types covered the effect of height, approach/departure ramp inclination(s), and intervals between successive humps on the final speed and the safety of road traffic. The impacts of braking before and acceleration after passing a hump on the pavement and the effect of the associated shocks on the riding comfort of both drivers and passengers and vehicle suspension were also investigated. What is missing in the available literature is information on the slowing effect of road humps depending on the longitudinal gradient of the street and the street’s landscaping. This article is intended to fill this gap by presenting the results of speed surveys carried out on three selected two-way streets located in home zones with different longitudinal gradients and a few humps of different designs that are placed at different intervals. Speeds were measured both before and after each of the successive humps. The “after” speeds were found to depend not only on the hump type and parameters but also on the direction of travel, vertical alignment of the street, parking location, and orientation of the parking space relative to the road axis. Full article

Cities are increasingly recognized as complex systems, emerging through conditional and history-dependent urban processes. To understand a complex urban phenomenon to the point where we can act on it, we need a quantitative yet holistic approach. In this paper, we report on a preliminary study on the gentrification of H Street NE in Washington, DC, USA. Popular accounts claim that this started in 2016, with wealthier new residents displacing poorer old residents. When we examined a cross-section of demographic, income, housing, commercial activity, and social activity data, we found a classic gentrification sweeping over H Street NE starting around 2000. These slow changes drove rapid changes in renter proportions and rents in one of the five census tracts making up the community, a wave of church closures, and a sudden doubling of restaurants and nonclassified businesses. Our results suggest that the gentrification of H Street NE is a small messy piece in a broader picture of urban transformation in Washington, DC. Full article

In the early stages of the COVID-19 pandemic and the resultant stay-at-home mandates, local governments in some cities in the United States implemented programs in response to the pandemic. This article focuses on Slow Streets, which were several programs implemented in eleven cities (Los Angeles, Oakland, San Francisco, Seattle, Portland, Denver, Chicago, Minneapolis, Detroit, Boston, and New York) in the United States. The programs were intended to keep people healthy by providing temporary public spaces on residential roads where residents were allowed to exercise and socialize. Some practitioners characterized the programs as tactical urbanism or tactical placemaking and as agile responses to the public health crisis. The programs deserve a critical reflection, considering their potential impact on community health and the limited amount of the literature on the program in terms of design justice, which is an approach to design that prioritizes marginalized communities and challenges their structural inequality. This reflective study attempts to fill that gap in the literature of architecture and urban design. This article aims to examine whether the Slow Streets programs promoted design justice. To address that aim, we propose a social justice framework to evaluate the program, because social justice is essential to design justice. Data from publicly available information online about the eleven cities’ Slow Streets programs, interviews, surveys, focus groups, and the interdisciplinary literature support the qualitative research. The study outcomes suggest that the Slow Streets program had limited success because their attention to the priorities of underserved populations was ineffective. We argue that while the programs provided a timely response to the pandemic, the programs did not adequately address the vulnerability of low-income communities of color due to the limited consideration of design justice. Building on the lessons from social justice and human geography, the article concludes with recommendations for future practices including place-cultivating and human geography-informed design to better serve vulnerable communities of color. Full article

Slow progress has been made on the study of thermal comfort studies in rural streets. The street construction lacks a corresponding theoretical basis, and the difference between city streets and township streets leads to the situation that the increased focus on improving the thermal comfort of city streets has not been effectively transferred to township construction. Therefore, this paper takes Huilongba Village as the research object, researching the mechanisms by which the spatial pattern of township streets influences the microclimate. This paper defines the spatial morphology of township streets by three indexes: the street aspect ratio, building density, and staggered arrangement of buildings. Additionally, it analyzes the microclimate influences of spatial morphology changes on township streets, verifies the validity of the ENVI-met model through field measurements, and designs a three-factor orthogonal experiment. With the help of software simulation, allowing for an investigation of the effects of indicators and their interactions on pedestrian thermal comfort, the optimal street spatial pattern construction scheme is proposed. The results show that the greater the density of street buildings, the more obvious the cooling effect and the better the comfort; in the staggered arrangement of buildings, the higher the high point of the building is to the south, the lower the overall temperature of the street and the better the cooling effect; and the larger the aspect ratio of the street, the better the cooling effect. Through orthogonal test and ANOVA, we can obtain the relationship between the contribution of each index to air temperature and the Universal Thermal Climate Index (UTCI) as street aspect ratio > building density > staggered building arrangement, and the overall thermal comfort of the street is the best when the aspect ratio of the street building is 1.5, the density of the building is 100%, and the south side of the building is higher. This study can provide a basis for rural street construction and thermal comfort retrofitting. Full article

The exploitation of urban subsurface space in urban inventory planning is closely connected to the quality of urban environments. Currently, the construction of underground pedestrian streets is characterised by inefficiency and traffic congestion, making them insufficient for fulfilling the demand for well-designed and human-centred spaces. In the study of spatial quality, traditional evaluation methods, such as satellite remote sensing and street maps, often suffer from low accuracy and slow updating rates, and they frequently overlook human perceptual evaluations. Consequently, there is a pressing need to develop a set of spatial quality evaluation methods incorporating pedestrian perspectives, thereby addressing the neglect of subjective human experiences in spatial quality research. This study first quantifies and clusters the characteristics of underground pedestrian spaces using spatial syntax. It then gathers multidimensional perception data from selected locations and ultimately analyses and predicts the results employing machine learning techniques, specifically Random Forest and XGBoost. The research results indicate variability in pedestrians’ evaluations of spatial quality across different functionally oriented spaces. Key factors influencing these evaluations include Gorgeous, Warm, Good Ventilation, and Flavour indicators. The study proposes a comprehensive and applicable spatial quality evaluation model integrating spatial quantification methods, machine learning algorithms, and multidimensional perception measurements. The development of this model offers valuable scientific guidance for the planning and construction of high-quality urban public spaces. Full article

Raised junctions (RJs) are chosen more and more frequently by town planners and road designers in traffic calming (TC) projects. This choice is supported by analyses of the existing transport systems in question. Where a few raised junctions have been designed for the project, use of different paving options may be worth consideration. This article describes a situation where a few RJs were placed on a short street section, all of which were provided with a cobblestone or cobblestone pavement (SBP). In order to verify the commercial viability of this option, we examined the traffic conditions, assessed the severity of condition of the pavements under analysis, and estimated the vehicle accelerations (ACs) and decelerations (DEs) in two chosen study areas, further referred to as the first and second study area. Two noise surveys were also carried out for the purposes of this research: the first one after a few years of operation and the second one after another ten years. Considering the problems of sustainable road construction, many environmental factors were taken into account in the studies. Based on the experimental results, we could assess the effectiveness of using RJs as the only TC measure in 30 km/h zones and check whether the severity of pavement condition depended on the AC and DE values and if SBP can be recommended to mitigate environmental impacts of street traffic. Finally, two pavement structures are proposed to choose from, depending on the local transport system conditions and streetscape characteristics. In addition, the authors recommend the use of solar-power elements at RJs to enhance their visibility and increase the traffic slowing effect. Full article

Environmental issues related to global warming and urbanization are becoming more serious. Many studies have shown that urban vertical planting can effectively reduce ambient temperature. However, the impact of different vertical planting combinations on urban microclimate has rarely been studied in Taiwan. Thus, in this study, the impact of different proportions of green walls and green roofs on the environment is explored. Referring to 6 times 6 high-rise buildings of 90 m in the ideal city. FLUENT was used to simulate the average climatic conditions of the Taipei Station in the past ten years’ summer. Since the actual building has openings that cannot reach 100% vertical plant coverage, the coverage is calculated based on the proportion of the green coverage area to the area of bare walls and roof decks. We had four options, including case 1 without greening, case 2 (green wall 25% + green roof 75%), case 3 (50% green wall + 50% green roof), and case 4 (75% green wall + 25% green roof). The research results show that at the height of the pedestrian layer (1.5 m), the wind speed of urban streets is reduced due to the obstruction of surrounding buildings. The installation of wall greening slows down the wind speed and reduces the ambient temperature, which is better than roof greening. In the urban canopy (90.5 m), as the Z-axis height increases, the higher the green roof ratio, the higher the wind speed. To improve the overall urban wind below 100% of the total greening balance of walls and roofs, it is recommended that wall greening be 50–75% and roof greening be 25–50%. Full article

A significant number of new metered parking systems have been introduced in recent years by the local authorities of various spa towns in Poland in connection with home zone conversion projects. The traffic signs posted in these locations were limited to the beginning and end of the demarcated parking area. Traffic circle (TC) is an example of a traffic calming measure (TCM) used in home zones to slow down the traffic (case study—home zone in a small spa village). This article presents the results of a study investigating the speed reductions obtained within a home zone and a traffic circle used as traffic calming measure. The indispensable speed surveys were carried out in relation to this study in two periods: in summer when the streets are crowded with tourists and in September with little pedestrian traffic. Two research hypotheses were formulated as part of the speed data analysis to verify the slowing effect of the traffic circle and the relevance of the traffic circle’s design parameters and location, road function and the surrounding streetscape. For each hypothesis, statistical analyses were carried out using two nonparametric tests: two-sample Kolmogorov–Smirnov test and median test. The third research hypothesis formulated in this study was related to sustainable development factors related to fuel consumption and traffic-related air pollution, including carbon dioxide, carbon monoxide, nitrogen oxide and hydrocarbons. This hypothesis was verified by estimating the amount of air pollution in the home zone under analysis in three different situations (scenarios): in summer with the travel speed reduced by pedestrian traffic to ca. 8–10 km/h, in September with a small number of pedestrians and 20–25 km/h resulting speed between traffic circles, reduced at the traffic circle, and in a theoretical 30 km/h zone with 25–30 km/h assumed speed between traffic circles, dropping at the traffic circle. These analyses confirmed the appropriateness of the traffic circle as a home zone traffic calming measure, as long as its design is based on a detailed analysis of the relevant factors, including location, road function and the surrounding streetscape. Full article

Demographic and economic shrinkage has become a common trend in the current urbanisation environment, especially for small cities in developed countries. The desired socio-economic redevelopment of these cities has been significantly affected by the functional, organisational, financial, and professional constraints caused by both shrinkage and city size. Paradoxically, this slow development has enabled better preservation of their historic cores, urban heritage, and traditional culture. Nevertheless, the aforementioned local constraints have a profound impact on sustainable urban regeneration, and successful examples are still quite rare. This research presents an inspiring case—a small museum quarter in Sombor, Serbia. Museum quarters are a relatively new concept in culture-led urban regeneration; all known examples are located in big cities. Hence, this research tries to create an innovative methodological link between two theoretical fundaments: the role of cultural heritage in shrinking small cities and its expression through a museum quarter as one of the concepts of culture-led urban regeneration. An analytical framework for the aforementioned single case study is derived by forming this link. The main findings underline that the museum quarters in shrinking small cities should be developed in a micro-format to rationally address and the limited local resources. Furthermore, in contrast to museum quarters in big cities, they should be physically detached from the main retail street to enhance their separate identity and should be internally balanced in both spatial and functional aspects, meaning that the key museum/cultural institutions are equally dispersed throughout the quarter and clearly interconnected by a pedestrian-friendly open public space. Full article

Recent critical events brought attention to the increasing exposure of urban environments to both slow and rapid onset disasters, which arise from both anthropogenic and natural causes. These events have particularly severe effects on historic centres, which are characterized by high levels of vulnerability and valuable assets exposed to risk. To minimize the impact on tangible and intangible cultural heritage values, especially in outdoor public areas such as squares and streets, it is crucial to establish coherent mitigative and adaptive solutions for different types of hazards. This research presents a methodology aimed at defining levels of multi-vulnerabilities in historic districts in the Apulia Region (Italy), considering the recurrent hazards to which the latter is prone. It uses a multi-step process based on structured and non-structured methodologies and tools for single risks, examined in combination, to determine the main properties characterizing the vulnerability assessment. The dataset was analyzed in a GIS environment to evaluate the selected Apulian case study (Molfetta) in Multi-Asynchronous Hazard scenarios, showing the compounded levels of criticalities for open areas and streets. This information is intended to support authority and emergency managers in identifying priority interventions and increasing the resilience of the outdoor public places. Full article

Urbanization has rapidly increased, leading to a wide range of significant disruptions to the global ecosystem. Road construction has emerged as the primary catalyst for such ecological degradation. As a result, it is imperative to develop efficient technological approaches for quantifying and tracking alterations in the ecological environment. Additionally, it is crucial to delve deeper into the spatial correlation between the quality of the ecosystem and the urban road network. This is of crucial importance in promoting sustainable development within the region. In this study, the research area selected was the Minjiang River Basin (MRB). We made optimal use of the Google Earth Engine (GEE) cloud platform to create a long-term series of remote sensing ecological index (RSEI) data in order to assess the quality of the ecological environment in the area. Additionally, we integrated digital elevation data (DEM) and OpenStreetMap (OSM) road network data to investigate the response mechanisms of RSEI with regard to elevation, slope, and the road network. The findings were as follows: (1) There were two distinct phases observed in the average value of RSEI: a slow-rising phase (2000–2010) with a growth rate of 1.09% and a rapidly rising phase (2010–2020) with a growth rate of 5.36%; the overall 20-year variation range fell between 0.575 and 0.808. (2) During the period of 2000 to 2010, approximately 41.6% of the area exhibited enhanced ecological quality, whereas 17.9% experienced degradation. Subsequently, from 2010 to 2020, the proportion of the region with improved ecological quality rose to 54.0%, while the percentage of degraded areas declined to 3.8%. (3) With increasing elevation and slope, the average value of RSEI initially rose and then declined. Specifically, the regions with the highest ecological quality were found in the areas with elevations ranging from 1200 to 1500 m and slopes ranging from 40 to 50°. In contrast, areas with an elevation below 300 meters or a slope of less than 10° had the poorest ecological quality. (4) The RSEI values exhibited a rapid ascent within the 1200 m buffer along the road network, while beyond this threshold, the increase in RSEI values became more subdued. (5) The bivariate analysis found a negative correlation between road network kernel density estimation (KDE) and RSEI, which grew stronger with larger scales. Spatial distribution patterns primarily comprised High–Low and Low–High clusters, in addition to non-significant clusters. The southeastern region contained concentrated High–Low clusters which covered approximately 10% of the study area, while Low–High clusters accounted for around 20% and were predominantly found in the western region. Analyzing the annual changes from 2000 to 2020, the southeastern region experienced a decrease in the number of High–Low clusters and an increase in the number of High–High clusters, whereas the northwestern region showed a decline in the number of Low–High clusters and an increase in the number of non-significant clusters. This study addresses a research gap by investigating the spatial correlation between road distribution and RSEI, which is vital for comprehending the interplay between human activities and ecosystem services within the basin system. Full article

The need for safe pedestrian movement implies subtracting and modifying space dedicated to vehicles, especially in urban areas. Traffic control measures aim to reduce or modify the width of the carriageway and force the correct use of the space by pedestrians through two approaches: the former is hard and includes physical barriers and the latter is soft and induces psychological fashion effects on the drivers. This paper presents vertical and horizontal devices integrated by landscaping, planting, or other similar works to slow motor vehicle speed, narrow traffic lanes, and/or create smaller distances for pedestrian crossings. Mobility and boundary issues are considered to discuss their warrants and potential impacts. Indeed, the effects of speed or volume treatments should be investigated through a comprehensive multicriteria analysis without overlooking pedestrian level of service, access and connectivity to residents and emergency vehicles, drainage and snow issues, loss of on-street parking lots, and environmental goals in terms of noise and emissions to air reduction. Full article

City densification and greening are two priority urban-policy objectives, for the coming years, aimed at making cities more resilient to climate change, slowing the spread of urbanization and improving the quality of life in cities. These are sometimes contradictory objectives that require fine and deep analysis to create approaches and methods that combine them. The most recent research has presented so-called small urban green spaces (SUGSs) as a viable alternative to achieve this double objective. This was the starting point of this research, which used GIS digital analysis and microscale fieldwork to study the possibilities of greening an excessively dense and low-quality urban space in the city of Pamplona (Spain). The results thereof showed that the urban structure of this neighbourhood contains a large number of small spaces with no specific use or function—residual, surface and vertical spaces—and that are simply undefined remnants between buildings and streets, or party walls that were never built. Only these surface spaces occupy a total area that is twice the size of the existing green spaces. Based on these results, this work explores the possibility of increasing the green areas of the neighbourhood through new SUGSs and the creation of a green corridor that increases environmental and social connectivity and the quality of life in the studied space. Full article

Slow-moving landslides are widespread natural hazards that can affect social and economic activities, causing damage to structures and infrastructures. This paper aims at proposing a procedure to analyze road damage induced by slow-moving landslides based on the joint use of landslide susceptibility maps, a road-damage database developed using Google Street View images and ground-displacement measurements derived from the interferometric processing of satellite SAR images. The procedure is applied to the municipalities of Vaglio Basilicata and Trivigno in the Basilicata region (southern Italy) following a matrix-based approach. First, a susceptibility analysis is carried out at the municipal scale, using data from landslide inventories and thematic information available over the entire municipalities. Then, the susceptibility index, the class of movement and the level of damage are calculated for the territorial units corresponding to the road corridors under investigation. Finally, the road networks are divided into stretches, each one characterized by a specific level of risk (or attention required) following the aggregation of the information provided by the performed analyses. The results highlight the importance of integrating all of these different approaches and data for obtaining quantitative information on the spatial and temporal behavior of slow-moving landslides affecting road networks. Full article