Road Model Research Articles

Порівняльний аналіз засобів ліквідації наслідків надзвичайних ситуацій природного характеру

У статті наведено результати порівняльного аналізу тактико-технічних характеристик вітчизняних зразків дорожньої та землерийної техніки та існуючих зразків провідних країн світу, які використовуються для ліквідації наслідків природного характеру. На основі отриманих результатів обґрунтовані перспективні напрямки розвитку засобів даного типу.

Assessing the applicability of the highway safety manual to gravel roads: A case study of Wyoming

Gravel road safety is a crucial area of road safety since gravel roads represent a substantial proportion of the entirety of the nation’s roadway network. Also, gravel roads pose inherent hazards that are otherwise absent in paved roads. Nonetheless, research related to gravel road crash count prediction models, known as safety performance functions (SPFs), was rarely undertaken. SPFs are required for identifying high crash risk locations, or hot-spots, and assessing changes in crash counts before and after implementing safety countermeasures. This research offers a diagnosis of the applicability of the Highway Safety Manual (HSM) to gravel roads in Laramie County, Wyoming. Even though the HSM does not address gravel road safety, the most appropriate methodology, provided by the HSM, for predicting counts of crashes on gravel roads is that of rural two-lane highways. This methodology is applied to Laramie County’s conditions and, as per the results, it is interpreted that the methodology is not applicable to such conditions. Therefore, developing SPFs for Wyoming’s conditions are recommended even though this involves labor hours, expertise and costs. Also, including a chapter in the HSM, devoted to gravel road safety, is suggested.

ISSUES OF DESIGNING AND RESTRUCTURING THE ROUTE NETWORKS OF PUBLIC PASSENGER URBAN GROUND TRANSPORT

The urban passenger public transport as an important element of social infrastructure of megalopolises directly influences the quality of life of city residents, development of town-planning, social and economic potential. Efficiency of urban transport directly depends on the right choice and well-sought designing of its routes.The objective of the research was to develop based on the overview of existing methods for designing route networks of urban public passenger transport an updated technique allowing to restructure existing routes. The analysis of route network design methods permitted to reveal their advantages and disadvantages. An improved methodology for designing route networks is proposed, aimed at solving the problems of restructuring existing route networks and at practical implementation of the results considering existing constraints. The technique to design route networks of city districts and of small towns is based on the model of road and street network, shown as a detailed graph with subsequent consideration of the arrays of connections of all the vertices of the graph with several points of gravity. QGIS geoinformatics software used to build the graph allows to analyze, visualize, and facilitate the operations with the detailed graph of the transport network of a city district.Identifying of rational itineraries between points of departure and of gravity is executed by purposed selection of options by criterion of minimum travel time spending. Shaping out of routes is based on principles of integration of the most possible number of points (vertices of the graph) into the route.The application of an improved technique will allow to consider the changing demand of the population for transport services, make adjustments to the existing route network, thereby satisfying the population’s need for transportation and increasing the efficiency of urban transport networks and motor transport enterprises.

We Are on the Way: Analysis of On-Demand Ride-Hailing Systems

Problem definition : Recently, there has been a rapid rise of on-demand ride-hailing platforms, such as Uber and Didi, which allow passengers with smartphones to submit trip requests and match them to drivers based on their locations and drivers’ availability. This increased demand has raised questions about how such a new matching mechanism will affect the efficiency of the transportation system—in particular, whether it will help reduce passengers’ average waiting time compared with traditional street-hailing systems. Academic/practical relevance : The on-demand ride-hailing problem has gained much academic interest recently. The results we find in the ride-hailing system have a significant deviation from classic queueing theory where en route time does not play a role. Methodology : In this paper, we shed light on this question by building a stylized model of a circular road and comparing the average waiting times of passengers under various matching mechanisms. Results : We discover the inefficiency in the on-demand ride-hailing system when the en route time is long, which may result in nonmonotonicity of passengers’ average waiting time as the passenger arrival rate increases. After identifying key trade-offs between different mechanisms, we find that the on-demand matching mechanism could result in lower efficiency than the traditional street-hailing mechanism when the system utilization level is medium and the road length is long. Managerial implications : To overcome the disadvantage of both systems, we further propose adding response caps to the on-demand ride-hailing mechanism and develop a heuristic method to calculate a near-optimal cap. We also examine the impact of passenger abandonments, idle time strategies of taxis, and traffic congestion on the performance of the ride-hailing systems. The results of this research would be instrumental for understanding the trade-offs of the new service paradigm and thus enable policy makers to make more informed decisions when enacting regulations for this emerging service paradigm.

Development of a Simplified Agency Life-Cycle Costing Tool for Gravel Roads

Understanding how roads behave is necessary both for their design and also to make sure that suitable and appropriate maintenance is programmed and carried out effectively. The problem is that this is not an easy task because there are many variables that affect road performance, and these differ from place to place. This is true of both paved and unpaved roads. Most countries have a large network of rural unpaved roads that require regular maintenance at relatively high total cost over many years. If the performance of such roads can be improved, especially in whole life terms, their costs can be reduced. Decision support tools such as the highway development and management system have been developed based on several studies in different countries. The performance models developed as a result of these studies often contain many variables and require extensive data collection before they can be used. This is often beyond the resources available. To improve this situation and to develop better understanding of the performance of gravel roads, this study was undertaken in six countries. It was found that two material characteristics, namely plasticity product and grading modulus, had a major effect on the performance of gravel roads, and were found to predict the performance of gravel roads to an acceptable level of accuracy. The results of the study were used to develop a simple life-cycle costing model for gravel roads that allows engineers to improve the performance of gravel roads and to reduce whole life costs.

Iterative Method for Predicting Uneven Bridge Approach Settlement (BAS) Caused by Vehicle Loads

With the development of the transportation, the bridge approach settlement (BAS) received great attention which can result in structure deterioration of the bridge and road, costly maintenance, and hazardous driving conditions. Therefore, accurate prediction of BAS is important. In this paper, a methodology using the iterative procedure is presented to predict the long-term BAS. In this method, the dynamic deviator stress is obtained by a 3D finite element road model and the settlement is calculated by an empirical model with the dynamic deviator stress. Then, the settlement is used as the excitation of the vehicle model for updating the load in the 3D road model. After several iterative calculations, the long-term BAS can be obtained. The comparison between the iterative method and the empirical method is presented. Also the parametric study of the empirical equation is performed. A simplified equation considering the iterative procedure is proposed for engineering practice. Computed results showed that the permanent settlement predicted by the iterative method is larger than that calculated by the empirical method. Also, the parameters of the empirical equation have great effects on the settlement prediction. The applicability of the new empirical equation is also proved.

Interacting multiple model-based adaptive control system for stable steering of distributed driver electric vehicle under various road excitations

Distributed driver electric vehicle (DDEV) works under various road excitations in practice, which may cause the changes in steering performance significantly. However, the various road excitations are not a priority for stable steering problem of DDEV, and this possibly leads to unstable steering performance, particularly oversteer or tail flick. To solve this problem, an interacting multiple model-based adaptive control system (IMM-ACS) is presented in this work. The proposed IMM-ACS integrates an interacting multiple model controller (IMMC) and a stable steering controller (SSC). The IMMC is designed to establish an adaptive vehicle model based on four typical road models, and to improve the adaptability of control system to various road excitations by the model interaction method. The SSC is designed to guarantee the yaw and longitudinal stability based on the adaptive vehicle model, by the active steering and torque distribution, and the SSC is realized by the model predictive controller (MPC). Besides, this work establishes a Carsim-Matlab co-simulation platform, where the simulation is designed and the results show that the proposed IMM-ACS can achieve excellent steering performance for DDEV with the adaptive capacity.

Integrating three-dimensional road design and pavement structure analysis based on BIM

While many studies have investigated the application of BIM in helping the integration of architectural, construction or manufacturing projects, however, it has been barely used in road engineering due to the lack of pavement structure analysis in the present Road-BIM products. The aim of this research is to develop a framework for the integration of BIM and structure verification to improve the application of BIM in road engineering and thus reduce the mistake and repetition in pavement design. Relying on the capabilities of Dynamo, a three-dimensional road model with pavement controllable parameters was first established. Successful implementation of this step can facilitate the designer with more flexible and convenient needs in design process. Secondly, a subroutine is developed based on Python to combine Dynamo with the Mechanistic-Empirical Pavement Design Guide (MEPDG) which provides the pavement structure analysis. As a response to long-term development between BIM and road engineering, this paper contributes by offering innovative and practical solutions for integration of road design and pavement analysis, which effectively solves the long-existing defect that the pavement structure cannot be analyzed in the environment of BIM, and thus, will significantly promote the further application of BIM technology in the road industry.

Research on Deterioration Model of Concrete Road in Cold Area

Based on the concrete damage data under the interaction of fatigue loads and freeze-thaw cycles, a concrete freeze-thaw cycle deterioration model and a fatigue damage deterioration model are established respectively. Based on the concrete fatigue damage deterioration model, a freeze-thaw influence factor is introduced, and a freeze-thaw The model of concrete degradation under fatigue and fatigue, and the relationship between freeze-thaw damage, fatigue damage and time are discussed separately, so as to study the remaining life of concrete roads.

Chassis trafficability simulation and experiment of a LY1352JP forest tracked vehicle

Based on the analysis of complex terrains and current forest transportation equipment, a forest tracked vehicle prototype LY1352JP was developed. The road model and the virtual prototype of the chassis were constructed using dynamic simulation software RecurDyn. The optimal tension of the vehicle as well as its capabilities for crossing trenches, climbing vertical walls, uphill and downhill slopes were simulated. The simulation results showed that the optimum tension force of the chassis of the vehicle was 63 kN (kilonewton), accounting for 45% of the total vehicle weight. The maximum trench crossing width and vertical obstacle climbing height were 1.35 m and 0.45 m, respectively. The maximum uphill and downhill angles were 50° and 45°, respectively. Tests on the prototype capacity for crossing trenches, and uphill and downhill driving were carried out. The test results were in agreement with the simulation results. A cross-country performance of a fire truck based on the tracked vehicle chassis was conducted in an old-growth forest. Tests verified that the vehicle has a strong forest trafficability performance and can meet the needs for forest transportation.

Heating performance enhancement for a road unit by using sectorial-finned pipe

This study proposes a sectorial-finned pipe in the hydronic road heating system with a three-dimensional road model to enhance the road heating performance. Three primary fin parameters, including sectorial fin angle, height, and spacing, were analyzed. The range analysis and ANOVA (analysis of variance) of the final average road surface temperature (Tasf), the maximum temperature difference of road surface (Tds), and the overall utility (Ut) were conducted through the orthogonal test method. The results showed that compared with the bare pipe, Tasf and Tds of the finned pipe increased by 0.63–1.37 K and 0.27–0.66 K, respectively, and ts0 of the finned pipe decreased by 0.22–0.44 h when the fin parameters were changed in specific ranges at the average air temperature of 258.15 K. The fin angle of 210° had the most suitable performances for road heating in terms of the thermal and economic targets. The range analysis revealed that the ranks of influence degree for Tasf, Tds, and Ut were height > spacing > angle, height > spacing > angle, and angle > spacing > height, respectively. ANOVA indicated that the parameters of height, spacing, and angle contributed Tasf in proportions of 80.56%, 10.25%, and 9.19%, those contributed Tds in proportions of 98.58%, 1.29%, and 0.13%, and those contributed Ut in proportions of 60.06%, 36.20%, and 3.74%, respectively. The optimum parameter combination for Ut was 210°, 20 mm, and 45 mm for the fin angle, height, and spacing, respectively. The results can provide a good guide for the design of sectorial-finned pipes in the hydronic road heating system.

Impact of regional versus local resolution air quality modeling on particulate matter exposure health impact assessment

As much of the population lives in close proximity to high-traffic roads, there is the potential for health impact assessments based on regional air quality modeling to underpredict health impacts. We compare the estimated health impacts from fine particulate matter (PM2.5) using local (0.04 × 0.04 km upscaled to census block group resolution) compared to regional (12 × 12 km resolution) modeled concentrations for three locations in Connecticut: Hartford, New Haven, and Willimantic. We use concentration estimates from the Comprehensive Air Quality Model with Extensions (CAMx) regional model and a hybrid model combining CAMx with a near road model (HYCAMR) in the Environmental Benefits Mapping and Analysis Program—Community Edition (BenMAP-CE) to calculate the difference in estimated human health impacts using different resolution air quality estimates from PM2.5 exposure including mortality, emergency room visits, hospitalizations, and asthma exacerbation. This provides an estimate of the potential underprediction of health impacts resulting from not accounting for the sharp concentration gradients in near road environments in urban areas. The fine-scale estimates capture the elevated concentrations near the roadways leading to increased estimates of overall mortality and morbidity in the population. We find an increase in the estimated likelihood of emergency department visits and mortality in the urban core. We also compare the impact of model resolution on the health impact estimates for different demographic groups. Of the locations investigated, we see the largest differences between demographic groups in Willimantic, CT. Our results indicate that using regional air pollutant concentrations may lead to an underprediction of human health impacts from air pollution exposure.

Application of AHP to Road Selection

The analytic hierarchy process (AHP), a decision-making method, allows the relative prioritization and assessment of alternatives under multiple criteria contexts. This method is also well suited for road selection. The method for road selection based on AHP involves four steps: (i) Points of Interest (POIs), the point-like representations of the facilities and habitations in maps, are used to describe and build the contextual characteristic indicator of roads; (ii) form an AHP model of roads with topological, geometrical, and contextual characteristic indicators to calculate their importance; (iii) select roads based on their importance and the adaptive thresholds of their constituent density partitions; and (iv) maintain the global connectivity of the selected network. The generalized result at a scale of 1:200,000 by AHP-based methods better preserved the structure of the original road network compared with other methods. Our method also gives preference to roads with relatively significant contextual characteristics without interfering with the structure of the road network. Furthermore, the result of our method largely agrees with that of the manual method.

IRI Performance Models for Flexible Pavements in Two-Lane Roads until First Maintenance and/or Rehabilitation Work

Pavement performance models play a vital role in any pavement management system. The Regional Government of Biscay (RGB) (Spain) manages a 1200 km road network and conducts pavement data collections, including the International Roughness Index (IRI) values. The aim of the paper is to develop an IRI performance model for two-lane roads with flexible pavement until the first maintenance and/or rehabilitation activity is performed. Due to the huge amount of available information, a deterministic model was selected. A literature review of deterministic models showed that, apart from age and traffic volumes, the pavement structure is a key factor. Therefore, it was decided to analyze the only road stretches whose entire pavement section was known (surface layer + base + subbase). Various variables related to age, traffic volumes and employed materials were introduced as possible factors. The multiple linear regression model with the highest coefficient of determination and all the variables significant included the real pavement age, the cumulated heavy traffic and the total thickness of bituminous layers. As the material employed in the surface layer could affect roughness progression, a qualitative variable was introduced to consider various surface materials. The model improved its accuracy, indicating that the surface layer material is also an influencing factor on IRI evolution.

Navigation Control of Cargo Transportation in the North of Russia

To develop the northern territories and ensure a normal life for people working there, significant quantities of construction materials, fuel, machinery, equipment, food and other goods are needed, a significant part of which must be transported to these territories. The peculiarity of the processes of transportation of goods to the Northern regions by road is that most of the transportation process is carried out using temporary roads which are called winter (or snow) roads [1, 2].Unlike permanent paved roads with corresponding infrastructure maintenance elements, winter roads have a traffic track representing a snow-cleared lane without specially prepared layers of pavement. The track has temporary landmarks [3, 4]. However, in bad weather, sudden changes in temperature, the route can be «lost», which negatively affects reliability and safety of the transportation process. Geoinformatics tools allow to create a virtual spatial model of a temporary road, which can be shown on an electronic map [5–7]. Satellite navigation tools form actual navigation data, which are « linked» to the route by means of geoinformatics. The current location of a vehicle on a winter road track can be displayed using an electronic terrain map on a display screen of an on-board telematic unit [8–10]. The objective of the article is to consider the main tasks that are solved by the supervisory control system when monitoring movement of vehicles on temporary winter roads. Using mathematical methods and special methods of analysis and planning of road transportation, a methodological basis has been developed to increase the level of automation of basic functions of the dispatch control of road transportation of goods in mixed multimodal traffic based on the use of information generated by GLONASS global navigation system. It is shown that the use of geoinformatics, mobile communications and satellite navigation will significantly improve reliability and safety of the processes of cargo transportation in the North of Russia. According to experts, the use of the proposed methodology allows reducing time for cargo handling by an average of 30 % and decision-making time by 50 %, as well as increasing the efficiency of using vehicles by reducing by 95 % the number of deviations from the planned schedule.

Comparing of Data Collection for Network Level Pavement Management of Urban Roads and Highways

Pavement condition data are collected by agencies to support pavement management system (PMS) for decision-making purpose as well as to construct performance model. The cost of pavement data collection increases with the increase of survey frequencies. However, a lower monitoring frequency could lead to unreliable maintenance decisions. It is necessary to understand the influence of monitoring frequencies on maintenance decision by considering the reliability of performance prediction models. Because of different maintenance conditions of urban roads and highways, their performance show different trends. In this paper, the influence of pavement monitoring frequency on the pavement performance models was investigated. The results indicate that low collection frequencies may result in delay in maintenance action by overestimating pavement performance. The collection frequency for Pavement Condition Index (PCI) can be reduced without compromising the accuracy of performance model, more work should be done to ensure the PCI data quality, thus to guarantee the rationality of maintenance decisions. Effect of frequency reduction on pavement performance (IRI) models of urban roads seems greater than on pavement performance (IRI) models of highways, which may lead to heavier monitoring work for urban roads management. This paper provided an example which demonstrated how a comparative analysis can be performed to determine whether the current data collection plan can provide sufficient data for time series analysis.

Investigation of the suspension of vehicles moving on stone roads

The paper studies the problem of traffic on mountain roads of natural origin. A mathematical model of a natural stone road is presented, the paper demonstrates also diagrams of “floodplain surface vs. support bed slope” correlation function. The calculation of the ride comfort of vehicles utilizes a four-mass model. Calculation results are demonstrated for a GAZ-3308 truck, as well as for a vehicle with half the suspension rate. The result obtained shows 30-50% reduction of the vibration load at a suspension rate reduction by 50%, dependent on the road type. The travel speed can be increased by 45% dependent on the road type and driver’s work time.

Research on the optimal design of municipal roads based on genetic algorithms

In order to improve the rationality of the design of municipal roads and realise the optimal planning and design of municipal roads, an empirical road optimisation design method based on genetic algorithm is proposed. In the sample of remote sensing image of municipal road, by solving the zero uniform ergodic characteristic and logical difference variable scale characteristic of objective function, the analysis and design of complex urban road pattern is realised, according to the principle of pixel correlation, genetic algorithm is used to optimise the design of municipal roads, and the image merging planning analysis model of municipal roads is constructed. The feature classification of municipal roads is carried out by genetic method, and the cross edge contour feature segmentation method of municipal roads is adopted. Optimise planning and network design of municipal roads. The simulation results show that this method can improve the rational layout of municipal road planning and improve the spatial planning capacity and traffic capacity of municipal roads.

Research on the optimal design of municipal roads based on genetic algorithms

In order to improve the rationality of the design of municipal roads and realise the optimal planning and design of municipal roads, an empirical road optimisation design method based on genetic algorithm is proposed. In the sample of remote sensing image of municipal road, by solving the zero uniform ergodic characteristic and logical difference variable scale characteristic of objective function, the analysis and design of complex urban road pattern is realised, according to the principle of pixel correlation, genetic algorithm is used to optimise the design of municipal roads, and the image merging planning analysis model of municipal roads is constructed. The feature classification of municipal roads is carried out by genetic method, and the cross edge contour feature segmentation method of municipal roads is adopted. Optimise planning and network design of municipal roads. The simulation results show that this method can improve the rational layout of municipal road planning and improve the spatial planning capacity and traffic capacity of municipal roads.

Ichthyosis: A Road Model for Skin Research.

The understanding of monogenetic disorders of cornification, including the group of diseases called ichthyoses, has expanded greatly in recent years. Studies of the aetiology of more than 50 types of ichthyosis have almost invariably uncovered errors in the biosynthesis of epidermal lipids or structural proteins essential for normal skin barrier function. The barrier abnormality per se may elicit epidermal inflammation, hyperproliferation and hyperkeratosis, potentially contributing to the patient’s skin symptoms. Despite this and other new knowledge about pathomechanisms, treatment of ichthyosis often remains unsatisfactory. This review highlights a series of approaches used to elucidate the pathobiology and clinical consequences of different types of ichthyosis, and related diseases with the ultimate goal of finding new and better treatments.