Search Results (12)

Street view imagery has become a vital tool for assessing urban street greenery, with the Green View Index (GVI) serving as the predominant metric. However, while GVI effectively quantifies overall greenery, it fails to capture the nuanced, human-scale experience of urban greenery. This study introduces the Front-Facing Green View Index (FFGVI), a metric designed to reflect the perspective of pedestrians traversing urban streets. The FFGVI computation involves three key steps: (1) calculating azimuths for road points, (2) retrieving front-facing street view images, and (3) applying semantic segmentation to identify green pixels in street view imagery. Building on this, this study proposes the Street Canyon Green View Index (SCGVI), a novel approach for identifying boulevards that evoke perceptions of comfort, spaciousness, and aesthetic quality akin to room-like streetscapes. Applying these indices to a case study in Nanjing, China, this study shows that (1) FFGVI exhibited a strong correlation with GVI (R = 0.88), whereas the association between SCGVI and GVI was marginally weaker (R = 0.78). GVI tends to overestimate perceived greenery due to the influence of lateral views dominated by side-facing vegetation; (2) FFGVI provides a more human-centered perspective, mitigating biases introduced by sampling point locations and obstructions such as large vehicles; and (3) SCGVI effectively identifies prominent boulevards that contribute to a positive urban experience. These findings suggest that FFGVI and SCGVI are valuable metrics for informing urban planning, enhancing urban tourism, and supporting greening strategies at the street level. Full article

Urban street comfort is a crucial measure of street environmental quality. However, traditional evaluations primarily focus on physical elements, often neglecting pedestrian perceptions. In this study, considering five core evaluation dimensions—safety, mobility, aesthetics, perceptibility, and convenience—an innovative quantitative evaluation model is proposed to assess pedestrian-perceived comfort on urban streets by integrating physical environmental factors and subjective experiences. This analysis comprises two steps: evaluation indicator extraction and weight application. Indicators are extracted from multi-source data (street-view images, real-time traffic data, points of interest, and pedestrian surveys) using a deep learning method. A comprehensive weighting method combining entropy weight and the analytic hierarchy process is used to determine the relative importance of each factor. This study focuses on Nanjing as a case study, and the results reveal significant variations across the five dimensions and their 11 secondary indicators. Street environment safety (0.143) is critical for street safety, while the degree of street traffic congestion (0.121) dominates street mobility. Street aesthetics is primarily influenced by building enclosure (0.105), and street convenience is strongly affected by the number of surrounding bus stops (0.260). Spatial analysis indicates higher comfort levels in urban centers due to well-developed infrastructure, whereas peripheral areas face challenges from inadequate facilities. Notably, areas around parks demonstrate elevated pedestrian-perceived comfort levels, highlighting the importance of green spaces. Overall, the proposed evaluation system provides new insights from the perspective of pedestrian experience and offers valuable guidance for urban planning and policy. Full article

Safety and crime prevention are significant concerns in both urban and rural areas. Crime Prevention Through Environmental Design (CPTED) guidelines provide an architectural strategy to deter criminal activities by implementing strategic design plans, particularly through effective lighting schemes in urban settings. These measures aim to reduce the fear of crime and enhance the overall quality of life. Enhanced street lighting plays a crucial role in environmental crime prevention by lowering both actual crime rates and the perceived risk of criminal activity in built environments. Current recommendations emphasize installing lighting in poorly lit areas for safety; however, assessing road surface luminance solely based on existing streetlights is insufficient. The research underscores that well-illuminated streets with uniform lighting and higher illuminance levels enhance pedestrian safety and comfort. In addition, this study proposes standardized illumination levels specifically for outdoor facial recognition to aid in identifying potential offenders. It outlines the critical vertical illuminance range and Color Rendering Index (CRI) values necessary for this purpose. Furthermore, metrics like the Brightness Index and Safety Index were developed to enhance night-time security and illustrate their correlation with crime rates. Ultimately, this research introduces quantitative lighting standards to enhance the effectiveness of CPTED guidelines, contributing to efforts to reduce crime incidence. Full article

One significant and simultaneously interesting problem in urban mobility has to do with the study of shared spaces where various categories of users coexist and act together. This paper aims to examine the behavior and preferences of pedestrians and cyclists, who both coexist in a shared space infrastructure along the seafront (which has a length of around 4.0 km) of the city of Thessaloniki, Greece. Furthermore, the problems caused by the coexistence, such as at the locations where there are pedestrian crossings on the bicycle lane, are recorded and evaluated. Traffic calming measures aimed at improving the existing situation in terms of safety and comfort for both pedestrians and cyclists are also explored. Data were collected through a web-based questionnaire survey, which was distributed via email to students and employees of Aristotle University of Thessaloniki. A total of 1194 questionnaires were collected in the framework of the survey during the year 2021, including responses from both pedestrians and cyclists. The questionnaires were analyzed through the use of descriptive and inferential statistics; the latter method suggested several significant differences in how each group of users (pedestrians or cyclists) perceived their behavior compared with the other. Latent variable and path models were estimated to investigate the behavior and attitude of users towards the crossings, examined as a function of their perception towards the other group; perception about the benefits of the infrastructure; preference for additional interventions; and overall opinion about the quality of the shared space area. The results suggest that forms of aggressive behavior, preference towards using the crossings, and the perceived safety are affected by the aforementioned factors. The results of this study can inform decision takers and decision makers in the area of land use regarding policy recommendations for facilitating interactions between pedestrians and cyclists in shared spaces. Full article

Environmental perception studies have long been constrained by research scales due to the difficulties in obtaining users’ perceptive data and constructing their relation to environmental attributes. With the help of big data from street view images, this study compares the visual comfort of streets across four Chinese megacities with evidently distinct geographical characteristics. A multi-method approach involving traditional comfort measurements, image analysis based on deep learning algorithms and spatial mapping using geographic information systems was used to investigate the visual components of urban streets at the city scale and their influential mechanisms. In general, the four cities ranked by visual comfort were Beijing first, then Shenzhen, Shanghai and Guangzhou. The results also suggested that the spatial distribution of the four cities’ street visual comfort is obviously different. In Shanghai and Beijing, streets with a higher comfort level are mostly concentrated within the central city, while the highly comfort streets are mostly distributed along the coast and rivers in Shenzhen and Guangzhou. Thus, it is reasonable to speculate that the streets’ visual comfort relates significantly to their urban planning and construction process. Moreover, seven indicators have been identified as influential to street comfort, among which ‘vegetation’, ‘terrain’ and ‘rider’ are positive indicators, while ‘architecture’, ‘pedestrians’, ‘motorcycles’ and ‘bicycles’ have negative influences. Comparing street comfort indicators of the four case study cities, it was observed that ‘vegetation’ and ‘terrain’ have the most consistent positive influences across cities, while the high visibility of ‘building’ on streets is most likely to lead to a low level of perceived comfort. The research outcomes provide applicable cues for large-scale street evaluation research and illustrate an efficient street design approach that can both respond to local characteristics and human perceptive needs. Full article

The improvement of the urban microclimate in the densely-built central areas of Mediterranean cities should be a key objective of integrated urban and transport planning and design in accordance with the UN Sustainable Development Goals on energy, sustainable cities, and climate action. The urban climate of cities in warm regions, already burdened by the urban heat island effect, is expected to worsen further due to the global climate crisis. This study investigates the performance of common environmental street design strategies on microclimate, thermal comfort, and air quality under extreme heat conditions in the Mediterranean city of Thessaloniki, Greece. A typology of streets was selected using criteria such as road functional classification and orientation, land uses, building height/street width ratio, the sky view factor, and the continuity/discontinuity of buildings. A conservative scenario (use of cool/photocatalytic and porous materials for sidewalks, lighter pavements, additional tree planting, installations of green roofs) and a radical scenario (pedestrianization and total traffic prohibition) of environmental design interventions were simulated using the ENVI-met 5.1 software. The research findings demonstrated that the car-free interventions combined with the use of environmentally friendly materials in the public realm could significantly reduce the heat island effect and mitigate gaseous pollutants. The perceived air temperature (Physiological Equivalent Temperature—PET index) can decrease by up to 15 °C in well-shaded locations and near building corners, while nitrogen oxides can be reduced by up to 87% when considering a more radical pedestrianization scenario. The standardization of environmental interventions following a typology of urban streets could support planners and decision-makers in detecting the appropriate solutions for improving the urban microclimate. Full article

The COVID-19 pandemic has considerably impacted pedestrians’ perceived comfort in a public setting. The virus’s transmissibility and social distancing restrictions have resulted in a shift in pedestrians’ perceived comfort, with more pedestrians becoming more conscious of other pedestrians and the distance between pedestrians. The changes in pedestrians’ perception have resulted in the Pedestrian Level Of Service (PLOS) models becoming outdated. The models may not accurately portray the actual status of pedestrians’ Level Of Service (LOS) according to the pedestrian needs during a pandemic, which generally lasts for a couple of years. These pandemics will happen in the future; hence, their impact on pedestrian comfort on sidewalks is worth considering. This research aims to analyse the effect of COVID-19 on PLOS by compiling data using a face-to-face questionnaire survey in the Melbourne Central Business District (CBD). From the 445 completed surveys, 72% of respondents extensively considered social distancing due to COVID-19 when commuting in the CBD, and 49% preferred a 1–1.5 m distance between pedestrians. In conjunction with an in-depth analysis of the data, an ordinal regression model has been used to analyse the factors that influence the perceived comfort of the pedestrians and estimate the PLOS. The model results show that pedestrian density, COVID-19 social distancing, continuous footpath, and pedestrian flow in opposite directions on the sidewalk greatly impacted the walking comfort of pedestrians during the pandemic. Full article

Strategies to mitigate urban heat islands are a recent issue in the Austrian capital, Vienna. In this study, the uhiSolver-v2106-0.21 software was used to evaluate the summer cooling effects and humidity production of small-scale facade greening and a green pergola located in two schools within the city. Based on on-site measurement data, the study revealed that small-scale greening measures are not able to substantially reduce ambient air temperature. On a hot summer day, at 3 p.m. local time (CEST), the maximum decrease amounted to 0.3 °C at 0.1 m from the facade greening as well as inside the green pergola. As for the apparent (perceived) temperature, a reduction of up to 4 °C was observed under the green pergola compared to the unshaded roof terrace. Hence, the simulation results show that, within urban areas, a significant improvement of thermal comfort in summer can only be achieved through large-scale greenery that provides shade for pedestrians. Full article

The perceived quality of street lighting influences pedestrians’ perceptions of safety and visual comfort, as well as outdoors activities at night. This study explores the association between street lighting attributes, such as illuminance and wavelength, and pedestrians’ feeling of safety (FoS) and perceived lighting quality (PLQ) in eight residential districts in Dalian, China. To achieve this goal, we combine remote sensing technology with ground investigation. The ground research includes physical measurements of lighting attributes, such as intensity, color temperature, and glare, as well as survey evaluations of pedestrians’ perceptions of safety and visual comfort. We also analyze the influence of several environmental factors, such as traffic volumes and vegetation, while accounting for personal characteristics of the observers, such as gender and age. Findings from the remote sensing reveal that Dalian’s residential districts differ substantially by their nighttime light emissions, with high concentration of strong red band (i.e., long wavelength) emissions occurring in Zhongshan and Jinzhou, and strong blue band (i.e., short wavelength) emissions found in central Zhongshan. Results from the ground surveys further indicate that a satisfactory level of FoS reaches at the illumination levels of 5–17 lx, and that people feel safer if nighttime light is warm and uniform. From a multiple regression analysis, it is also found that illuminance and uniformity are the main factors affecting PLQ under conditions of low or high illuminance, while glare and color temperature play a more significant role under high illuminance. In addition, a satisfactory level of PLQ is found at illuminance levels of 25–35 lx and light color temperature of 4000 K–5500 K. Full article

Computer games are considered a useful tool for educational purposes. Alternative media applications such as serious games combine edification with challenge and entertainment. Thus, learning becomes enjoyable, more comfortable, and more efficient. The paper presents the implementation of an educational computer game regarding traffic behavior awareness through the main stages of analysis, design, development, and evaluation, aiming at investigating the contribution of gamification in traffic safety. The game was developed as an advanced media education approach in Unreal Engine, encompassing various adventures. The game hero’s tasks are to move into the virtual city to complete a mission, follow road safety rules, and experience the adventures either as a pedestrian or as a vehicle driver. Research hypotheses/questions are tested concerning the gaming impact and the audience engagement through first-person storytelling to communicate and perceive traffic regulations. The results reveal that a properly developed educational game could become more engaging, amusing, and efficient. It could also enhance traffic awareness through experiential and mediated learning, also fostering social responsibility. Full article

Walking is an important transport mode for sustainable cities, but the usability of pedestrian environments for people with impaired vision is very limited after dark. This study compares the usability of a walkway, operationalized in terms of (i) the pedestrian’s ability to orient themselves and detect infrastructure elements, and (ii) the perceived quality of lighting in the environment (evaluated in terms of the perceived strength quality and perceived comfort quality). The study was performed in a city in southern Sweden, along a pedestrian route where observations and structured interviews had previously been conducted and after an intervention involving installing new lighting systems with LED lights. A mixed method analysis involving participants with impaired vision (N=14) showed that the intervention generally improved the walkway’s usability: observations indicated that the participants’ ability to orientate themselves and detect infrastructure elements increased, and the interviews showed that the intervention increased the perceived strength quality of the lighting along the walkway. However, the effects on the perceived comfort quality were unclear. It is therefore important to carefully evaluate new lighting systems to reduce the risk of creating an inappropriate lighting design that will limit walking after dark by people with impaired vision. Full article

Two types of methods are used to evaluate pedestrian comfort: pedestrian wind comfort and outdoor thermal comfort. To accurately ascertain the outdoor wind environment, wind speed is the only parameter considered. However, pedestrians may still feel discomfort when the perceived temperature is low, even though the wind comfort criterion has been satisfactorily fulfilled. The purpose of this study is, therefore, to investigate pedestrian comfort when the perceived temperature is low, especially in winter conditions. To achieve this, a pedestrian survey was conducted, and 588 respondents completed a questionnaire. The results show that pedestrians feel discomfort when the WCET (Wind Chill Equivalent Temperature) is low, with almost 40 percent of respondents answering that they feel discomfort in these conditions. In conclusion, the threshold wind speed of the winter season could be determined to be lower than that of the existing comfort criteria by applying the WCET. Full article