Road Orientation Research Articles

Comparison of Urban Environment Factors for Solar-Powered Vehicles

Abstract. Urban areas face significant environmental challenges, including high CO2 emissions largely attributed to the transportation sector. Introducing solar-powered vehicles (SPVs) presents a promising solution to reduce urban carbon footprints. However, in dense urban settings, the effectiveness of SPVs is often compromised by shading from buildings, which significantly diminishes solar power generation. This study explores the impact of shading on urban roads, aiming to identify roads with substantial shadow variations that affect solar energy harvesting. Using Geographic Information Systems (GIS) and hillshade analysis, the study examines how nearby buildings and road orientation influence shadow variability. The findings reveal considerable variability in shadow throughout the year, with significant fluctuations during transitional months like February, August, October, and November. These results highlight the importance of considering shadow patterns in urban planning and vehicle routing to optimise the use of solar energy in urban settings.

Energy, environmental and economic performance of bi-facial photovoltaic noise barrier applied in city scale

Solar energy in transportation reduces fossil fuel consumption and supports carbon neutrality. Photovoltaic noise barriers (PVNB) are used globally to harness renewable energy along roads. This study's novelty lies in the detailed consideration of road orientation and the application of bifacial photovoltaic technology when assessing the potential for large-scale deployment of PVNB. Bifacial PV technology captures solar radiation from both sides, enhancing energy efficiency. A mathematical model was established and validated to predict PVNB power output at 5° azimuth intervals. Geographic information system (GIS) technology was used to quantify trunk roads, motorways, and RNB in Shenzhen, China. Accordingly, the electricity generation potentials of PVNB, as well as the economic and environmental benefits were calculated. The installed capacity and power generation of PVNB in Shenzhen are 432.29 MW and 313.37 GWh, respectively. The levelized cost of electricity is 0.4781 CNY/kWh. Compared to a 600 MW coal-fired unit, 9119.09 tce of fossil fuel can be saved, with lifecycle carbon reduction of 3.80 Tg and net carbon reduction of 3.05 Tg.

Towards multi-variable tsunami damage modeling for coastal roads: Insights from the application of explainable machine learning to the 2011 Great East Japan Event

The accurate assessment of tsunami-induced damage to coastal roads is crucial for effective disaster risk management. Traditional approaches, reliant on univariate fragility functions, often fail to capture the complex interplay of variables influencing road damage during tsunami events. This study addresses this limitation by employing machine learning techniques on an extensive dataset compiled after the 2011 Great East Japan tsunami. The dataset, enriched with additional explicative variables accounting for the hydraulic features of the event and the physical characteristics at roads’ location, enables a comprehensive analysis of road damage mechanisms. Results indicate that while inundation depth remains a significant predictor, factors such as wave approach angle, road orientation and potential overflow from inland watercourses also play critical roles.

Study on the Morphological Analysis and Evolution of the Street Network in the Historic Urban Area of Changsha City from 1872–2023

This study focuses on the streets and spatial networks of the historic urban area in Changsha, the capital of Hunan Province, China, by mainly investigating the evolution of their geometric and topological characteristics. It draws on the theories and methods of urban morphology and space syntax, combines the digital historical maps at different times, and uses methods such as historical map spatial interpretation, geographic information system (GIS), sDNA tools, and urban morphological parameter analysis to explore and sort out the evolutionary process of the street and alley network in Changsha from the early modern period to the present. The paper constructs a parameter system for analyzing the street and alley network of historic urban areas from a geometric and topological perspective. It introduces the indicators of road density, road orientation, intersection density, and approaches such as closeness, betweenness, and intelligibility in space syntax into the parameter analysis framework of street and alley network morphology and spatial characteristics evolution. By comparing the changes in various parameters at different spatial scales, the process of the spatial order evolution of the street and alley network in the historic urban area is analyzed, and the evolutionary rules of the various periods’ morphological characteristics are extracted.

A traffic state prediction method based on spatial–temporal data mining of floating car data by using autoformer architecture

AbstractFloating car data (FCD), characterized by wide spatiotemporal coverage, low collection cost, and immunity to adverse weather conditions, are one of the key approaches for intelligent transportation systems to obtain real‐time urban road network traffic information. The research aims to utilize GPS data from taxis in Shanghai and vector geographic information data of the road network, with urban expressways as the research focus. Based on the different driving characteristics of expressways and the vehicles on the ramps below, a clustering analysis is employed to determine all floating vehicles traveling on the target road. Furthermore, an adaptive buffer zone consistent with the road orientation is established based on road vector geographic data. This allows for the extraction of FCD within segmented areas, and the average vehicle speed for that road segment is obtained through weighted calculations. This method fully exploits the natural characteristics of taxis in urban areas with a wide spatiotemporal distribution. The data effectiveness and coverage reach 90.2% and 85.7%, respectively, significantly surpassing the traditional grid‐based extraction method for FCD. Additionally, to capture the long‐term spatiotemporal dependencies of road network traffic states, a spatial–temporal autoformer (STAF) network based on spatial–temporal sequence autocorrelation is employed for traffic state prediction. The results indicate that the STAF method demonstrates good performance in medium‐ and long‐term prediction. We believe that the proposed FCD mining method in this paper provides a new approach for efficiently extracting large‐scale road network traffic states and conducting medium‐ to long‐term predictions.

The photovoltaic potential for electric vehicle charging along highways: A Dutch case study

AbstractThe large‐scale deployment of photovoltaics (PVs) along highways has the potential for the generation of clean electricity without competing for land use or burdening the power grid since energy for electric vehicles (EVs) can be generated locally on wastelands along highways near service stations. An analysis was carried out to evaluate the feasibility of integrating vertical bifacial solar modules into noise barriers. The approach involved integrating geospatial data with PV potential data using geographic information systems (GIS) technology. The results show a potential of around 200 GWh/year if all current noise barriers along highways in the Netherlands are considered suitable for PV module integration. Three case studies have been analysed regarding specific service stations for specific road orientations. It is shown that solar energy can charge more than 300 vehicles per day by combining bifacial PV noise barriers and standard mono‐facial PV modules on publicly available land along the highway in all three case studies, which is sufficient to meet 80% of the expected EV charging demand along highways in 2030.

Green infrastructure modelling for UHI control to urban thermal comfort: a case study of Temanggung urban area

ABSTRACT The Temanggung urban area in Central Java (Indonesia) already has considerable urban Green Infrastructure (GI), but the phenomenon of Urban Heat Island (UHI) has expanded to 268% in the last seven years. This study explores the theoretical gaps related to urban thermal comfort by combining tree management modelling as the independent variable and existing urban morphology as the dependent variable to identify the right place for the right tree using ENVI-met v5 simulations. We use the Universal Thermal Climate Index (UTCI) to determine urban thermal comfort, and our results showed a temperature decrease from 37°C (strong heat stress) to 32.5°C–35.5°C (moderate heat stress) and an average decrease of 1°C–3.5°C. These results were obtained by simulating the placement pattern of substations, land use zoning, tree size composition, paying attention to the type of road surface material, wind direction and speed and direction of road orientation, average air temperature, and location of building masses. This study provides a basis for consideration to assist local governments and researchers in managing GI in Temanggung Urban Area to create comfortable urban thermal comfort for their residents.

Investigation of heat stress on urban roadways for commuting children and mitigation strategies from the perspective of urban design

Rapid urbanization and global warming have triggered frequent heat waves that pose a threat to human survival, with a marked increase in childhood morbidity. While previous studies have explored the thermal environment of children's public activity places, only limited studies have focused on the commute of school children, which is a regular activity causing potential risk of heat stress. From an urban design perspective, this study systematically investigated the influence of building shade, road orientation and tree species on the thermal environment of commuting roads. The simulation results indicated that, regarding the reduction of road heat stress, the building shade has a greater impact that can reduce the mean radiant temperature by 3.22 °C to 21.25 °C, compared to the effect of tree shade (0.02–6.04 °C). Furthermore, planting street trees in a flexible manner to add building shade areas can enhance thermal safety. For road orientations, increasing shade areas of north-south road generates more benefits in heat stress mitigation (in the northern hemisphere). Finally, from the perspective of urban design/management and school children, a set of heat stress mitigation strategies are proposed to promote the thermal safety of school children and stimulate the development of a sustainable and healthy urban environment.

Large-scale road extraction from high-resolution remote sensing images based on a weakly-supervised structural and orientational consistency constraint network

Fully supervised road segmentation neural networks from remote sensing images rely on a large number of densely labeled road samples, limiting their potential in large-scale applications. In this paper, a weakly-supervised road segmentation network based on structural and orientational consistency (SOC-RoadNet) is proposed to learn road surface from open-source road maps, thus supporting high-quality large-scale road extraction. The open-source road maps can be made with scribble-labels to train the weakly-supervised SOC-RoadNet. However, these scribble-labels that represent the approximate location of road centerlines with only one-pixel width cannot provide supervision for road boundaries, leading to low road surface segmentation accuracy using scribble-supervised methods. Existing weakly-supervised road extraction networks deploy complex scribble-label propagation procedures to generate pseudo labels to train models and exploit image edge maps to refine road boundaries. Nevertheless, road edges in images are blurry due to occlusions and spectral-confusing backgrounds, limiting reliability when processing complex scenes. The proposed SOC-RoadNet is designed as a one-stage end-to-end architecture that directly learns road surface features from scribble-labels without extra label propagation procedures. Instead of using unreliable edge maps to regularize road boundaries, a structural consistency loss function is introduced to evaluate the structural similarity between road surface segmentation results and the input images for improved road boundary accuracy. Considering that roads are elongated targets with local directional consistency, orientation learning is integrated to SOC-RoadNet to improve road integrity. A road refining module was designed to aggregate the road surface features and road orientation features to further refine the road extraction results. The reference road orientation maps are generated from the scribble labels; thus, the results of orientation learning are supervised without extra input. Extensive experimental results on the public Deep Globe Road Dataset and four city-scale images confirm the effectiveness of our SOC-RoadNet in large-scale road extraction tasks.

The influence of spatiotemporal radial road on the outdoor thermal environment

The urban planning of squares with open space and the radioactive road is often seen in many cities. It forms a particular type of landscape and affects the traffic system and urban microclimate. However, the influence of city square spatial morphological indicators on the thermal environment at pedestrian height has not been studied well. This study took the most representative Zhongshan Square of Dalian as the case, the city with the most squares in China. The measurement analysis found that the central air temperature of the square is severe higher than the fixed points 250 m away, with a difference between 4.5 °C and 1.7 °C. The road location in the same orientation was the primary factor affecting the air temperature by 1.0 °C in the 500 m range by mobile measurement. The air temperature in the east-west was higher than in the north-south. The simulation results within 500 m proved that road orientation also affects air temperature. In the same direction, three types of roads with a significant height difference of buildings, broad streets, and straight roads will be conducive to ventilating and create a better thermal environment. This work contributes to urban planning development and decision-making around similar city squares with road networks.

Road extraction from satellite images with iterative cross-task feature enhancement

Recent study has shown that road orientation information is highly beneficial to the road extraction task. However, most existing approaches that integrate road extraction with orientation prediction in a naïve multi-task learning framework fail to explore their correlations, leading to unsatisfactory results with severe road discontinuity issues. In order to take full advantages of road orientation information to facilitate accurate road extraction, we propose an iterative cross-task feature enhancement network, which jointly optimizes the deep features for both road extraction and orientation prediction tasks in a mutually beneficial manner. To this end, we present two unique designs, namely, the semantic guided feature enhancement (SGFE) module and the orientation-aware feature aggregation (OAFA) module. The SGFE module is used to refine orientation prediction features by incorporating the semantic information of road extraction feature. Meanwhile, the OAFA module is able to enhance road extraction feature by adaptively deforming its receptive field according to the predicted road orientations. Our proposed network recursively alternates between these modules, permitting the extracted features to be collaboratively improved through cross-task information flow. We set new state of the art on two widely adopted benchmarks (67.00 road IoU on DeepGlobe [5] and 80.06 mIoU on Massachusetts [18]), which verifies the superiority of our method.11Our code is publicly available at:https://github.com/YinWeiling/Road-Extraction.

Simulation and Analysis of Influencing Factors of Pavement Thermal Environments in Guangzhou

Pavements are closely related to the livelihoods of urban residents as an important part of the urban road system. Based on the early field measurements of our team, we found that plant spacing, pavement orientation, and pavement material influence the pavement thermal environment. Our objective was to quantitatively evaluate the influence of various factors on pavements in Guangzhou along West Zhonghuan Road, Guangzhou University. Based on our team’s previous research, environment-met (ENVI-MET) numerical simulation software was used to simulate pavements under different road orientations, underlying surface materials, and plant distances. Quantitative analysis of the effects of different factor combinations on the temperature, humidity, wind speed, physiological equivalent temperature (PET), and radiant temperature (Tmrt) was performed. The results show that among the various factors affecting the thermal environment of pavement, street tree spacing was found to have the greatest effect on the thermal environment of pavement. The effect of direction is negligible; however, it has a significant effect on the wind speed. There was no significant difference in the air temperature and relative humidity between concrete and asphalt. The average air temperature of red floor tile was slightly lower than that of asphalt and concrete. Reducing the spacing of street trees can effectively reduce the penetration of direct solar radiation, physiological equivalent temperature (PET), and temperature (Tmrt) and improve pedestrian walking comfort. The results can serve as a reference for pavement design in Guangzhou and improve the wellbeing of citizens and promote environmental sustainability.

Road orientation affects the impact of roads on wildlife

Context Understanding the factors determining the impacts of roads and how they fragment landscapes limiting the movement of animals, is key to implement efficient mitigation measures. Aims Here we investigate if road orientation in relation to limiting resources, a largely overlooked factor on road impact assessments, can influence the movement of animals within a landscape where water resources are spatially clustered. Methods We evaluated movement by monitoring animal tracks on unpaved roads: two with a North–South orientation and two with an East–West orientation. Key results Animals were more likely to follow roads leading to limiting resources (i.e. East–West orientation), confirming human linear structures can facilitate wildlife movements. Carnivores were more likely to follow roads with any orientation and for longer compared to ungulates, whereas ungulates followed roads mainly in the orientation of limiting resources. Conclusions Road orientation affects how roads influence the movement of animals in landscapes where resources are distributed along a spatial gradient with different effects for ungulates and carnivores. Implications The key implications of this work affect the planning and implementation of mitigation strategies and safety measures. Our results suggest road-crossing infrastructure and fences will be most important in roads traversing a gradient to allow wildlife movement while preventing collisions. For roads along a gradient, crossing structures may be less important, but fences or appropriate signage could be useful to prevent or warn drivers of animals travelling on the road.

Evolutionary artificial intelligence algorithms for the one-way road orientation planning problem with multiple venues: An example of evacuation planning in Taiwan.

In large-scale events such as concerts and sports competitions, participants often leave the venue at the same time to return to their respective destinations. Improper traffic planning and traffic light operation usually lead to traffic congestion and road chaos near the sites. Rapid evacuation of participants has become an important issue. In this work, a one-way road orientation planning problem with multiple venues is studied in which all roads near the venues are to be scheduled into a one-way orientation with strong connectivity to increase the evacuation efficiency of participants. In accordance with Robbins' theorem and a random sequence of integers, an encoding scheme based on module operator is presented to construct a strongly connected graph and plan a one-way orientation for all roads. The proposed encoding scheme is further embedded into four artificial intelligence approaches, namely, grey wolf optimization, immune algorithm, genetic algorithm, and particle swarm optimization, to solve the one-way road orientation planning problem such that the total distance of all vehicles from venues to their destinations is minimized. Numerical results of test problems with multiple venues in Taiwan are provided and analyzed. As shown, all four algorithms can obtain the best solution for the test problems. The new presented encoding scheme with four algorithms can be used to effectively solve the one-way road orientation planning problem for the evacuation of participants. Moreover, grey wolf optimization is superior to the other three algorithms and particle swarm optimization is faster than the other three algorithms.

Study of the thermal environment of sidewalks within varied urban road structures

Vehicle-oriented transportation has been dominating road design for decades and worsening the urban outdoor thermal environment. Introducing the concept of human-oriented design in road reconstruction, this study considered road orientation, number of planting strips, and leaf area index (LAI) of trees when developing alternative road structures that aims to provide pedestrians a more satisfying walking experience. The ENVI-met V4 model, was used to simulate the thermal environment of sidewalks within the scenarios. Results demonstrated that road orientation had significant but time-varied effects on mean radiant temperature (Tmrt) and physiological equivalent temperature (PET). Two Tmrt and PET peaks were noticed in East-West (EW) oriented roads; but only one peak was found in North-South (NS) roads due to that the aisle buildings on NS roads shaded sidewalks and reduced the solar radiation received in the morning.Changing tree’s LAI from low to high on EW and NS roads can reduce the mean Tmrt by 5.5 and 3.0 °C, and the mean PET by 3.2 and 1.7 °C, respectively. Simulation results also showed that adding one more planting strip in the middle of roads did not reduce the mean Tmrt (all cases less than 1.7 °C) and mean PET (all cases less than 1.2 °C) much. A significant synergistic cooling effect from road orientation, number of planting strips, and LAI of trees on the sidewalks’ Tmrt and PET was observed. Thus, the number of planting strips and LAI of trees could be more precisely applied while considering road orientation. These results provide quantitative and alternative information for designers to create a better walking experience for pedestrians.

Hydrological effects of resource-access road crossings on boreal forested peatlands

Resource-access road crossings are expected to alter peatland hydrological properties by obstructing surface and sub-surface water flows. We conducted a multi-year study at two boreal peatlands – a forested bog and a shrubby rich fen near Peace River, Alberta – to study the impacts of resource access roads on the hydrology of adjacent peatland. Field measurements (bi-weekly depth to water table and hydraulic head, one-time hydraulic conductivity) during the growing seasons (May-August) of 2016 and 2017 were taken from sampling plots representing: 1) sides of the road (upstream and downstream); 2) distance from the road (obstruction); and 3) distance from culverts. Compared to the growing season average precipitation for the region of 1.8 mm d−1, the study period had very wet conditions in 2016 (3.7 mm d−1) and dry conditions in 2017 (1.1 mm d−1).In contrast to our assumptions, resource access road disturbed the surface and sub-surface water flow at the bog, but the effect was minimal at the fen as the road orientation was nearly parallel to the flow direction at the latter. At the bog, the shallowest depth to water table position was observed at upstream areas closer to the road, when culverts were located >20 m distance from transects. In contrast, when culverts were present <2 m from the transects, variation in hydrological conditions between upstream and downstream areas were greatly reduced. Our work shows road effects on peatland hydrology could be minimized by aligning roads parallel to the water flow direction when possible. If water flow is perpendicular to the road, adequate spacing and installation of culverts could help to reduce flow obstruction.

Effects of Roadside Trees and Road Orientation on Thermal Environment in a Tropical City

Emerging tropical cities are experiencing rapid population growth and development, which can greatly affect the thermal environments. The effects of roadside trees and road orientation on the outdoor thermal environment were investigated on four different roads in Kuala Lumpur, Malaysia. Field measurements were conducted to assess outdoor thermal environments, where the selection of sites was based on different roadside tree morphological features and road orientations. Outdoor air temperature (Ta), relative humidity (RH), globe temperature (Tg), wind speed (WS), and wind direction (WD) were measured. Absolute humidity (AH) was estimated based on relative humidity and air temperature. Planting dense canopy trees with an average sky view factor (SVF) of 0.07 reduced the mean radiant temperature (Tmrt) by 35% and the physiological equivalent temperature (PET) by 25%. East–West (E–W) and Northwest–Southeast (NW–SE) oriented roads had high PET values of 41 °C and 43 °C, respectively. North–South (N–S) and Northeast–Southwest (NE–SW) orientated roads had lower PET values (37 °C), providing improved outdoor microclimate. Roadside trees provided greater cooling potential in E–W and NW–SE oriented roads. The findings are useful for urban road design in tropical cities in order to improve the outdoor thermal environment and pedestrian comfort.

Road orientation of housing subdivision in Majlis Bandaraya Iskandar Puteri, Malaysia

Street network is a city crucial element. The current guidelines of road design generally include road width, cross-sections and street hierarchy which are to be taken into consideration during the design phase of the network. Research have shown that road orientation affects the quality of a housing subdivision. However, there are limited studies on street orientation with most of them concentrating on the effects of the orientation on housing subdivision rather than the factors which give rise to its orientation. This research aims to analyse the street network of housing subdivisions located within Majlis Bandaraya Iskandar Puteri (MBIP) to identify the aspects which influence its orientation. Street networks of 71 housing subdivisions under the administration of MBIP were extracted using the OS Mnx Python programming tool to visualize the street networks in terms of polar charts. The findings of the study imply that the size of a housing subdivision does not affect the manner of streets within it are designed. Street pattern is associated with the time of development and the socioeconomic status of the community within the housing subdivision. Such findings contribute to better understanding of street orientation and can assist urban planners to create a better living environment.

Spatial differentiation characteristics and influencing factors of urban and rural settlements in Tibet, China

Located in the hinterland of the Qinghai-Tibet Plateau, Tibet has very limited space sui-table for human living. The spatial distribution of settlements in Tibet is restricted by multiple factors. To reveal the spatial distribution characteristics and explore the main influencing factors of settlements in Tibet, we extracted patch data from the high-resolution images of urban and rural settlements in Tibet based on visual interpretation. Methods such as the kernel density analysis, space hotspot detection, Geodetector and others were applied to analyze the spatial differentiation characteristics and influencing factors, with the aim to provide reference for future settlements selection and formulation of relevant policies on regional economic development in the plateau region. The results showed that urban and rural settlements in Tibet had a clustering pattern, with different overall density distribution. Lhasa was a high-density core, and Ngari Prefecture, Qamdo, and Nyingchi were the "core-edge" structures with low-density edges. The settlement density of Lhasa was as high as 220 ind·km-2, while that of Ngari Prefecture, Qamdo and Nyingchi was only 5.7 ind·km-2. The gap between the two regions was more than 43 times. The clustering of high and low value clusters in urban and rural settlements was remarkable. The number of high-value of large plaques was rare, and the number of low-values of small plaques was dominant. The area of high-value cluster accounted for only 3.7%, concentrated in Lhasa and Lhoka. The proportion of low value cluster area reached 67.2%, mainly distributed in Ngari Prefecture and Nagqu on the Qiangtang Plateau. There were six types of urban and rural settlements in Tibet, which formed two circle structures in the "One River and Two Streams" basin and the "Three Rivers" basin. From the inside to the outside, the large plaque-dominated type, medium-density and cluster-like type, high-density and point-scattered type, low-density and point-scattered type and high-altitude and uninhabited type was successively distributed. Lhasa was dominated by medium-density and cluster-like type, accounting for 31%. Lhoka was dominated by low-density and point-scattered type, accounting for 38%. Qamdo was mainly low-density and point-scattered type, accounting for 51%. The Ngari Prefecture, Nagqu and Shigatse were dominated by high-altitude and uninhabited type, and the proportion of the Ngari Prefecture was as high as 64%. The effects of different factors on the spatial distribution of urban and rural settlements in Tibet were distinctly different. The population and GDP were highly decisive for the distribution of urban and rural settlements. In addition, urban settlements showed strong road orientation, while rural settlements were more characterized by river orientation.

Crack damage investigation of paved highway embankment in the Tibetan Plateau permafrost environments

Field surveys focusing on the crack damages in paved embankment of the Qinghai-Tibet Highway were carried out at 17 sections. Some severe cracks were found in the road embankment constructed on the permafrost ground affecting the smooth operation of the highway. Road orientation, thaw settlement, crack width and length were measured at the typical crack sections. Besides, embankment slope surface temperatures were monitored at two road sections, and the temperature difference as high as 10 °C was observed in the cold winter time. Three scenarios were employed in the numerical modeling to assess the impact of climate warming, embankment slope surface temperature, and embankment itself on the underlying permafrost evolution process. Thereafter, a method was introduced to obtain the thaw settlement of the road embankment according to the simulated thawing front depth. The results indicate that the thaw settlement difference across the road embankment width is the main cause results in the crack damages. This uneven thaw settlement can be amplified due to the presence of the original ground slope. Additionally, climate warming intensified the underlying permafrost degradation and accelerated the thawing front penetrating into the subgrade permafrost. In summary, road orientation, original ground slope, climate warming, and underlying permafrost type are major but not the sole causes for the crack damages of the paved embankment in the Tibetan permafrost environments. It is recommended that steep slope and ice-rich permafrost ground should be avoided in the early design of the highway embankment.