scholarly journals The use of three-dimensional visualization tools to detect deficiencies in geometric roadway designs

2014 ◽  
Vol 20 (1) ◽  
pp. 54-69 ◽  
Author(s):  
Aurenice da Cruz Figueira ◽  
Ana Paula C. Larocca ◽  
José Alberto Quintanilha ◽  
Felipe Issa Kabbach Jr

The use of three-dimensional (3D) visualization technologies in the field of transportation sciences has contributed not only to the assessment of the impact of a road project on its surroundings but also to the development and study of elements of the geometric design itself. The present study aimed to assess the effectiveness of the use of 3D visualization tools in the detection of poor compatibility between the horizontal and vertical alignments of a road project. The assessment was performed by conducting tests with groups of participants who were students from a civil engineering course with no experience in the development of geometric roadway designs. These participants each assessed two road stretches: one stretch with unflawed coordination between the vertical and horizontal alignments of the road and another stretch in which this coordination had been intentionally distorted. It was used an application software for roadway geometric designs that allowed the creation of a video of the trajectory of the targeted road. Subsequently, the participants answered a questionnaire that aided the interpretation of the results regarding the design deficiencies in road layouts perceived from the 3D visualization of the roadways.

2000 ◽  
Vol 6 (S2) ◽  
pp. 282-283
Author(s):  
Matthew Dougherty ◽  
Wah Chiu

Sophisticated tools are needed to examine the results of cyro-microscopy. As the size and resolution of three dimensional macromolecular structures steadily improve, and the speed at with which they can be generated increases, researchers are finding they are inundated with larger datasets and at the same time are compelled to expediently evaluate these structures in unforeseen ways. Integration of EM data with other types of information is becoming necessary and routine; for example X-ray data, 3D EM reconstructions, and theoretical models, must be evaluated in concert to discount or propose hypothesis. To create such tools, the developer must take into account not only the empirical and theoretical possibilities, but also they must master the human factors and computational limits. During the last five years, the National Center for Macromolecular Imaging (NCMI) has progressed from a remedial 3D visualization capability to a collection of visualization tools allowing researchers to focus on the discovery phase of biological research.


2021 ◽  
Vol 10 (8) ◽  
pp. 557
Author(s):  
Qiuping Li ◽  
Haowen Luo ◽  
Xuechen Luan

Heavy rain causes the highest drop in travel speeds compared with light and moderate rain because it can easily induce flooding on road surfaces, which can continue to hinder urban transportation even after the rainfall is over. However, very few studies have specialized in researching the multistage impacts of the heavy rain process on urban roads, and the cumulative effects of heavy rain in road networks are often overlooked. In this study, the heavy rain process is divided into three consecutive stages, i.e., prepeak, peak, and postpeak. The impact of heavy rain on a road is represented by a three-dimensional traffic speed change ratio vector. Then, the k-means clustering method is implemented to reveal the distinct patterns of speed change ratio vectors. Finally, the characteristics of the links in each cluster are analyzed. An empirical study of Shenzhen, China suggests that there are three major impact patterns in links. The differences among links associated with the three impact patterns are related to the road category, travel speeds in no rain days, and the number of transportation facilities. The findings in this research can contribute to a more in-depth understanding of the relationship between the heavy rain process and the travel speeds of urban roads and provide valuable information for traffic management and personal travel in heavy rain weather.


Author(s):  
Viktor Gaidaichuk ◽  
Liudmyla Shevchuk ◽  
Olena Bilobrytska ◽  
Serhii Baran

The article presents the results of a computer analysis of the stress-strain state of a multilayer asphalt pavement under the influence of traffic loads. Based on the finite-element model of coating deformation, a study was made of the mechanical behavior of the system considered for various structural schemes for the existence of vertical cracks in various layers of the structure under the action of vertical transport loads. The effects of stress concentration in the system due to high-gradient deformation fields and structural imperfections of the multilayer coating were found. Multi-layer asphalt roads are one of the most common construction projects. Based on a review of the tasks of science about their strength and durability, these structures can be attributed to significantly complex types of building systems. This is primarily due to the multi-parameter nature of the factors that determine their design, material properties, types of loads and the impact on them, as well as their operating conditions. Therefore, designers of road structures and specialists who are involved in the theoretical modeling of the mechanical behavior of layered massifs during operation have to take into account many additional factors that complicate their work. These include the most important design and operational features of these systems, which significantly affect the nature of the distribution of stress and strain fields, as well as their intensity. First of all, they include special structural schemes of the road and pavement. It is a multilayer three-dimensional package having disproportionately different sizes along each direction. Hidden (as well as obvious) vertical cracks and horizontal delamination of the structure, sometimes permissible under operating conditions, can be added to the design model of a structure. Such violations of the continuity of the system also lead to discontinuity of the displacement functions, which further worsens the system’s performance and complicates the task of its modeling. The materials of the coating layers, which include asphalt concrete, cement, crushed stone, sand, soil, and others, also bring particular specificity to the work of the road structure. All of them differently resist tensile, compression and shear, and asphalt concrete is also elastic-viscous - plastic material, whose properties are largely dependent on temperature.


2019 ◽  
Vol 11 (22) ◽  
pp. 2625 ◽  
Author(s):  
Luis Iglesias ◽  
César De Santos-Berbel ◽  
Valero Pascual ◽  
María Castro

The safe and efficient operation of highways largely depends on the adequate provision of sight distance. Small unmanned aerial vehicles (UAVs) can be utilized to efficiently complete data acquisition very soon after identifying an issue when searching for potential highway safety risks. A double grid flight is proposed to obtain an adequate three-dimensional (3D) recreation of the road environment, ensuring an unbiased sight distance output. Then, a dense cloud point is derived through a Structure from Motion Multi-View Stereo process. The point cloud is classified to produce both a terrain model, characterized by its resolution, and a 3D-object model, characterized by the maximum edge length of the entities. The resulting road environment model is utilized to calculate sight distance in a geographic information system. The results enabled the detection of accident-prone locations caused by sight distance limitations. Moreover, the impact of the 3D modeling parameters on the results was assessed.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2493 ◽  
Author(s):  
Huawen Yan ◽  
Weigong Zhang ◽  
Dong Wang

Automobile proving ground is important for the research of vehicles which are used for vehicle dynamics, durability testing, braking testing, etc. However, the road in automobile proving grounds will inevitably be damaged with the extension of the service life. In most previous research, equipment similar to a laser profilometer was used to detect the quality of the road, the principle of which is to reflect the quality of the road by measuring the roughness of the pavement. This method ignores the elastic deformation of the road itself when the vehicle is traveling and it is difficult to compensate for the error. Therefore, this paper presents a new method based on a force sensor to reduce the impact of elastic deformation, such as tire deformation, pavement deformation, and wheel rim deformation. In this study, force sensors mounted on the wheels collect the three-dimensional dynamic force of the wheel. The presented method has been tested with two sets of cobblestone road loads, and the result shows that the load intensities imposed by the test vehicle on the target road are 88.3%, 91.0%, and 92.05% of the intensity of the load imposed by the test vehicle on a standard road in three respective dimensions. It is clear that the proposed method has strong potential effectiveness to be applied for wear detection and analysis of a special road.


Designs ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 40
Author(s):  
Kareem Othman

Over the last few years, autonomous vehicles (AVs) have witnessed tremendous worldwide interest. Although AVs have been extensively studied in the literature regarding their benefits, implications, and public acceptance, research on the physical infrastructure requirements for autonomous vehicles is still in the infancy stage. For the road infrastructure, AVs can be very promising; however, AVs might introduce new risks and challenges. This paper investigates the impact of AVs on the physical infrastructure with the objective of revealing the infrastructure changes and challenges in the era of AVs. In AVs, the human factor, which is the major factor that influences the geometric design, will not be a concern anymore so the geometric design requirements can be relaxed. On the other hand, the decrease in the wheel wander, because of the lane-keeping system, and the increase in the lane capacity, because of the elimination of the human factor, will bring an accelerated rutting potential and will quickly deteriorate the pavement condition. Additionally, the existing structural design methods for bridges are not safe to support autonomous truck platoons. For parking lots, AVs have the potential to significantly increase the capacity of parking lots using the blocking strategy. However, the implementation of this parking strategy faces multiple issues such as the inconsistent marking system. Finally, AVs will need new infrastructure facilities such as safe harbor areas.


2011 ◽  
Vol 261-263 ◽  
pp. 1119-1123
Author(s):  
Zi Jian Wang ◽  
Sheng Xie Xiao

This article in a typical road slope model as an example, through large-scale general-purpose finite element simulation software ANSYS/LS-DYNA rockfall on the slope of the roadbed impact for three-dimensional dynamic analysis in the roadbed, slope geological parameters and falling stone initial state is not at the same time on the roadbed impact the results of comparative analysis. The result is the mountain slope of the road construction project provides reference.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiao Yan ◽  
Hongwei Zhang ◽  
Bing Hui

The water accumulated in the rutted road sections poses a threat to the safety of vehicles. Water-filled ruts will cause partial or complete loss of the friction between tires and the road surface, leading to driving safety hazards such as hydroplaning and sliding. At present, the maximum water depth of left and right ruts is mostly adopted to analyze the safety of water-filled ruts, ignoring the uneven change of ruts in the driving direction and the cross-section direction, which cannot fully reflect the actual impact of asymmetric or uneven longitudinal ruts on the vehicle. In order to explore the impact of water-filled ruts on driving safety, a three-dimensional (3D) tire-road finite element model is established in this paper to calculate the adhesion coefficient between the tire and the road surface. Moreover, a model of the 3D water-filled rut-adhesion coefficient vehicle is established and simulated by the dynamics software CarSim. In addition, the influence of the water depth difference between the left and right ruts on the driving safety is quantitatively analyzed, and a safety prediction model for the water-filled rut is established. The results of the case study show that (1) the length of dangerous road sections based on vehicle skidding is longer than that based on hydroplaning, and the length of dangerous road sections based on hydroplaning is underestimated by 9.4%–100%; (2) as the vehicle speed drops from 120 km/h to 80 km/h, the length of dangerous road sections obtained based on vehicle sliding analysis is reduced by 93.8%. Therefore, in order to ensure driving safety, the speed limit is controlled within 80 km/h to ensure that the vehicle will not skid. The proposed method provides a good foundation for the vehicles to actively respond to the situation of the water-filled road section.


Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 117
Author(s):  
Christian Weich ◽  
Manfred M. Vieten ◽  
Randall L. Jensen

While training and competing as a runner, athletes often sense an unsteady feeling during the first meters on the road. This sensation, termed as transient effect, disappears after a short period as the runners approach their individual running rhythm. The foundation of this work focuses on the detection and quantification of this phenomenon. Thirty athletes ran two sessions over 60 min on a treadmill at moderate speed. Three-dimensional acceleration data were collected using two MEMS sensors attached to the lower limbs. By using the attractor method and Fourier transforms, the transient effect was isolated from noise and further components of human cyclic motion. A substantial transient effect was detected in 81% of all measured runs. On average, the transient effect lasted 5.25 min with a range of less than one minute to a maximum of 31 min. A link to performance data such as running level, experience and weekly training hours could not be found. The presented work provides the methodological basis to detect and quantify the transient effect at moderate running speeds. The acquisition of further physical or metabolic performance data could provide more detailed information about the impact of the transient effect on athletic performance.


2021 ◽  
Author(s):  
C. Jayalath ◽  
◽  
K.K.G.P Somarathna ◽  

Scope creep has been a day-to-day occurrence in almost every major road project causing a considerable cost overrun with no early dimple. This paper offers a critical appraisal on the dominant causes behind scope creep in the road projects. A comprehensive literature survey was undertaken to explore the factors specifically contributing scope creep and various control measures that are adopted, among other purposes, in at least reducing the impact due to scope creep in the final delivery of road projects. The study included interviews with 15 experts to identify major issues and add their hands-on experience. A questionnaire survey was subsequently administered among 100 industrial personnel having a cost management background in order to evaluate the effectiveness of the key performance indicators (KPIs) in terms of taming scope creep. Results from the study showed that concomitant client instructions on additional features, unclear scope and incremental changes cause scope creep throughout the project. Among 53 KPIs identified, the most effective KPI that enables adequate control of scope creep in road projects is the cost efficiency ratio. The results enable comprehending the causes of scope creep and its resultant net effect on cost control.


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