Road Elements Research Articles

Assessing Distraction Potential of Augmented Reality Head-Up Displays for Vehicle Drivers.

To develop a framework for quantifying the visual and cognitive distraction potential of augmented reality (AR) head-up displays (HUDs). AR HUDs promise to be less distractive than traditional in-vehicle displays because they project information onto the driver's forward-looking view of the road. However, AR graphics may direct the driver's attention away from critical road elements. Moreover, current in-vehicle device assessment methods, which are based on eyes-off-road time measures, cannot capture this unique challenge. This article proposes a new method for the assessment of AR HUDs by measuring driver gaze behavior, situation awareness, confidence, and workload. An experimental user study (n = 24) was conducted in a driving simulator to apply the proposed method for the assessment of two AR pedestrian collision warning (PCW) design alternatives. Only one of the two tested AR interfaces improved driver awareness of pedestrians without visually and cognitively distracting drivers from other road elements that were not augmented by the display but still critical for safe driving. Our initial human-subject experiment demonstrated the potential of the proposed method in quantifying both positive and negative consequences of AR HUDs on driver cognitive processes. More importantly, the study suggests that AR interfaces can be informative or distractive depending on the perceptual forms of graphical elements presented on the displays. The proposed methods can be applied by designers of in-vehicle AR HUD interfaces and be leveraged by designers of AR user interfaces in general.

Reproduction of experimental spatio-temporal structures in traffic flows using mathematical model based on cellular automata theory

The paper deals with mathematical modelling of traffic flows on urban road networks using cellular automata theory. Two versions of the model based on Nagel-Schreckenberg traffic flow model were created. They both are multilane, include complex driver behaviour algorithms and allow simulating traffic on various road elements and on road networks. One of the models is using “slow-to-start” concept that represents the fact that it takes drivers more time to accelerate when they just start moving in comparison with the situation when their speed is already above zero. The goal of the work was to reproduce experimental spatio-temporal patterns on traffic velocity diagrams with the created models and to research the difference between them and to determine the range of the applicability for each. Parallel algorithms of realisation for the models are created. Computations are carried out for each element of the road (T or X type intersection, on-ramp, road fragment with widening or bottleneck, straight road fragment, etc.) separately and in parallel, that allows performing calculations on various complex road networks. Different kinds of average characteristics (such as, for instance, the capacity of the crossroad) can be also obtained using the created program package. Computations show that the results obtained are in an agreement with experimental data and therefore can be used for practical traffic flow modelling in cities.

Influence of Calibration Factors on Crash Prediction on Rural Two-Lane Two-Way Roadway Segments

Calibration factors are applied in the Highway Safety Manual predictive method for rural two-lane, two-way roadway segments to adjust the estimate for local conditions. This research aims to evaluate and recommend improvements related to the estimation of these calibration factors. An aggregated and disaggregated analysis was performed to study the influence of different calibration factors on the prediction of the number of crashes in North Carolina. As a result, those calibration factors based on both types of road elements (horizontal curves and tangents) led to overestimating and underestimating the number of crashes on tangents and horizontal curves, respectively. Furthermore, the calibration factors based on fatal and injury crashes allowed a more accurate estimation of the predicted number of crashes than those calibrated considering all severity levels. Therefore, it is recommended to apply different calibration factors for each type of road element and each type of crash severity.

ГЕОМЕТРИЧЕСКОЕ МОДЕЛИРОВАНИЕ ПОВЕРХНОСТНЫХ ФОРМ ОТГОНА ВИРАЖА АВТОМОБИЛЬНОЙ ДОРОГИ НА ОСНОВЕ ЦИКЛОГРАФИЧЕСКОГО ОТОБРАЖЕНИЯ

Theoretical studies on highway design consider the road axis as a basic element that defines spatial forms of other road elements: the roadway, the roadside verge, and the slopes. Based on this principle of shaping of the road elements, mathematical models of shaping based on the cyclographic method of simulation of space and its objects are proposed in this article. Shaping of surface forms of road elements on its transition segment and on a curve essentially differs from shaping on a straightway section by a number of specific features that impede and complicate the process of theoretical and practical shaping. The article describes the possibility to construct mathematical models of shaping a superelevation attainment segment on the basis of cyclographic mapping of the road axis. An example with detailed analysis and visualization of each stage of shaping is given. Results of the work can be used for development of modern specialized CAD of highways.

Optimization of structural elements of transport vehicles in order to reduce weight and fuel consumption

In global competition manufacturing companies have to produce modern, new constructions from advanced materials in order to increase competitiveness. The aim of my research was to develop a new composite cellular plate structure, which can be primarily used for structural elements of road, rail, water and air transport vehicles (e.g. vehicle bodies, ship floors). The new structure is novel and innovative, because all materials of the components of the newly developed structure are composites (laminated Carbon Fiber Reinforced Plastic (CFRP) deck plates with pultruded Glass Fiber Reinforced Plastic (GFRP) stiffeners), furthermore combines the characteristics of sandwich and cellular plate structures. The material of the structure is much more advantageous than traditional steel materials, due mainly to its low density, resulting in weight savings, causing lower fuel consumption and less environmental damage. In the study the optimal construction of a given geometry of a structural element of a road truck trailer body was defined by single- and multi-objective optimization (minimal cost and weight). During the single-objective optimization the Flexible Tolerance Optimization method, while during the multi-objective optimization the Particle Swarm Optimization method were used. Seven design constraints were considered: maximum deflection of the structure, buckling of the composite plates, buckling of the stiffeners, stress in the composite plates, stress in the stiffeners, eigenfrequency of the structure, size constraint for design variables. It was confirmed that the developed structure can be used principally as structural elements of transport vehicles and unit load devices (containers) and can be applied also in building construction.

Hierarchical Merging & Generalization Method of Three-Dimension City Model Group Based on the Theory of Spatial Visual Cognition

In order to simplify the three-dimensional building group model, this paper proposes a clustering generalization method based on visual cognitive theory. The method uses road elements to roughly divide scenes, and then uses spatial cognitive elements such as direction, area, height and their topological constraints to classify them precisely, so as to make them conform to the urban morphological characteristics. Delaunay triangulation network and boundary tracking synthesis algorithm are used to merge and summarize the models, and the models are stored hierarchically. The proposed algorithm should be verified experimentally with a typical urban complex model. The experimental results show that the efficiency of the method used in this paper is at least 20% higher than that of previous one, and with the growth of test data, the higher efficiency is improved. The classification results conform to human cognitive habits, and the generalization levels of different models can be relatively unified by adaptive control of each threshold in the clustering generalization process.

Macroscopic fundamental diagram in simple street networks

Macroscopic fundamental diagrams (MFDs) on simple street networks are studied analytically and numerically. We consider nonlinear circuit model that consists of road elements with piecewise linear fundamental diagram. We find that MFDs of the model are discontinuous and sawtooth like. Meanwhile, simulations of optimal velocity model on the same street networks yield continuous MFDs, that are observed in real urban traffic.

The new generation electrical railway drives

The safe realization of railway traffic requires a safe railway route. The intersection of railway tracks, which is one of the railway road elements is operated by railway drive. Therefore, the article has been devoted to modern railway drives, which take a significant role in the realization of safe railway transport. The evolution of further technical solutions of railway drives is forced by a continuous increase of expectations in relation to ensuring the safety and railway transport quality.

GEOTECHNICAL INFLUENCE OF UNDERLYING SOILS TO PAVEMENT FAILURE IN SOUTHWESTERN PART OF NIGERIA

Roads in Nigeria are usually constructed without in-depth knowledge of the subsoil that serves as the foundation for the road elements. Road failures are often associated to poor construction materials or inadequate design without cognisance of the underlying soils. Engineering properties of ten bulk soil samples collected from the subgrade of Arigidi/Oke-Agbe highway were investigated to determine their suitability for highway pavement. Results show that all the subgrade soils below the failed locations have higher plasticity indices, which is an indication of their high swelling potential, and they are classified as A-7-6 clayey soils with high-water adsorption capability (16.1 – 22.4%) compared to subgrade soils from the stable locations. Low compacted density (1325 – 1928 Kg/m3), extremely poor CBR values; 8 – 31% (unsoaked) and 3 – 8% (soaked) which indicate percentage reduction in strength of the soils up to 77% on exposure to excessive moisture and the predominance of fines (> 59%) in the soils are responsible for the degree of instability. Furthermore, soft to low stiffness (49 – 131 kN/m2) and poor permeability of the subgrade materials underlying the pavement result to the failure characteristics witnessed. This study shows that the suitability and behaviour of subgrade soil is dependent on its engineering properties.

Calibration of the inertial consistency index to assess road safety on horizontal curves of two-lane rural roads

One of every four road fatalities occurs on horizontal curves of two-lane rural roads. To this regard, many studies have been undertaken to analyze the crash risk on this road element. Most of them were based on the concept of geometric design consistency, which can be defined as how drivers’ expectancies and road behavior relate. However, none of these studies included a variable which represents and estimates drivers’ expectancies.This research presents a new local consistency model based on the Inertial Consistency Index (ICI). This consistency parameter is defined as the difference between the inertial operating speed, which represents drivers’ expectations, and the operating speed, which represents road behavior. The inertial operating speed was defined as the weighted average operating speed of the preceding road section. In this way, different lengths, periods of time, and weighting distributions were studied to identify how the inertial operating speed should be calculated.As a result, drivers’ expectancies should be estimated considering 15 s along the segment and a linear weighting distribution. This was consistent with drivers’ expectancies acquirement process, which is closely related to Short-Term Memory.A Safety Performance Function was proposed to predict the number of crashes on a horizontal curve and consistency thresholds were defined based on the ICI. To this regard, the crash rate increased as the ICI increased.Finally, the proposed consistency model was compared with previous models. As a conclusion, the new Inertial Consistency Index allowed a more accurate estimation of the number of crashes and a better assessment of the consistency level on horizontal curves.Therefore, highway engineers have a new tool to identify where road crashes are more likely to occur during the design stage of both new two-lane rural roads and improvements of existing highways.

Study of Driving Behavior in Ilioupolis, Athens According to the Environmental Affordances Theory

The urban space is characterized by specific qualities that may contribute to, or mitigate the social life. These qualities were described by James Gibson as “environmental affordances”. But beyond social life, such environmental affordances can affect other human behaviors, such as driving behavior. Such an approach can be particularly useful, since the objective in most European cities is to regain the social character of roads and streets and thus to reduce the speeds on the roads and the number of cars. Through this research, conclusions can be drawn related to road elements that contribute to the development of high traffic speeds to prevent their use during urban planning while encouraging the use of other qualities that will support the maintenance of low speeds of cars. In the light of the above, the specific research focuses on a neighborhood of the southern suburbs of Athens, Ilioupolsi. Through observations and an electronic survey, conclusions are drawn on the behavior of drivers in Ilioupolis. Finally, an attempt is made to generalize the effects of the specific physical characteristics in order to optimize the design of cities where the roads will be social spaces in addition to vehicle traffic channels.

Effect of Adverse Weather Conditions on Vehicle Braking Distance of Highways

The effect of adverse weather conditions on the safety of vehicles moving on different types of roads and measuring its margin of safety have always been a major research issue of highways. Determining the exact value of friction coefficient between the wheels of the vehicle and the surface of the pavement (usually Asphalt Concrete) in different weather conditions is assumed as a major factor in design process. An appropriate method is analyzing the dynamic motion of the vehicle and its interactions with geometrical elements of road using dynamic simulation of vehicles. In this paper the effect of changes of friction coefficient caused by the weather conditions on the dynamic responses of three types of vehicles: including Sedan, Bus, and Truck based on the results of Adams/car Simulator are investigated. The studies conducted on this issue for different weather conditions suggest values ranging from 0.04 to 1.25. The results obtained from simulation based on Adams/car represent that the friction coefficient in values of 0.9, 0.8, 0.7, 0.6 do not effect on braking distance significantly and it is possible to attribute them all to dry weather condition. However, as it was anticipated the values of 0.5, 0.4, 0.28 and 0.18 have significant differences in braking distance. Hence, the values of 0.5, 0.4, 0.28 and 0.18 can be attributed to wet, rainy, snowy and icy conditions respectively.

Study of the influence of impact velocity and angle of impact against a motorcyclists´ protection systems design and neural damage sustained using numerical methods

ABSTRACTMPS (Motorcyclists´ protection systems) play an essential role in the reduction of fatalities and morbidity involved in motorbike and moped accidents, since they offer protection from impact against road elements such as guardrail posts and nearby elements such as traffic signs, trees, etc. For the standardisation of such elements, different regulations have been developed which, by means of experimental tests, allow the simulation of those accidents through tests at a specific velocity and angle. Nevertheless, there is the possibility that, under different angles and velocity, those systems fail to be safe. To assess this, a series of accidents involving diverse angles and velocities have been studied through virtual tests by using numerical models and the finite elements method with a view to obtaining data on head acceleration and neural damage sustained in the event of collision against MPS. In addition, the accidentology for this type of vehicles has been studied in order to break accidents down according to impact angle and velocity impact range as well as age category and gender of those sustaining injuries. To that aim, homologated commercial MPS have been analysed in order to get the variation of the main biomechanical indexes depending on the impact angle and velocity; the results thus obtained have allowed us to determine the real security level of the MPS studied. This information has been extrapolated to determine the level of security provided by MPS. Finally some modifications in the homologation regulations to improve safety of MPS have been suggested.

Методологічні аспекти створення геоінформаційної системи лісових автодоріг

Здійснено аналіз тенденцій розвитку геоінформаційних систем (ГІС) в лісовій галузі та міжнародних вимог стосовно запровадження природозберігаючих технологій на базі оптимальної транспортної мережі як передумови для реального запровадження принципів сталого ведення лісового господарства. Обґрунтовано необхідність наявності об’єктивних даних про транспортну мережу лісових підприємств. Подано методичні підходи до створення ГІС лісових автодоріг, які передбачають подання інформації про лісові автодороги як лінійні об'єкти з відомими координатами вздовж дороги та наявністю певної кількості каліброваних точок, тобто коректно розташованої лінії, що відображає дорогу, і відомостей про неї у вигляді таблиць та фото (креслень), які відображають її технічні та експлуатаційні характеристики. Також висвітлено особливості структури і порядку роботи та операційні можливості дослідної ГІС лісових автодоріг, розробленої для ДП «Осмолодське лісове господарство».

Assessment of sulfur concrete properties for use in civil engineering

Sulfur concrete is a material that was introduced to the civil engineering industry as a substitute of a typical concrete in which cement is a binder. Sulfur concrete properties are provided by a sulfur polymer produced in the process of synthesis of the ordinary sulfur with modifiers that prevent a process of crystallization of sulfur what results in stabilizing sulfur polymer structure. The purpose of this investigation was to evaluate characteristics of sulfur concrete, which was designed with combustion products. It was established that mechanical parameters of sulfur concrete should correspond with properties of a cement concrete used in production processes of prefabricated elements of road and construction industry. Accurateness of parameters of a designed mixture was confirmed and rated by a series of tests of hardened concrete – physical, mechanical (compression strength), durability in harsh environment. The test results confirmed low water absorption, high resistance to wear abrasion, high freeze-thaw scaling resistance (surface weathering) in a salty environment and high compressive and tensile strength of individual compositions. However, due to the internal structural damage, the freeze-thaw-attack cube tests did not prove the freeze-thaw resistance of the sulfur concrete specimens. The reason was low freeze-thaw-attack resistance of sulfur binders.

Multilane Traffic Flow Modeling Using Cellular Automata Theory

The paper deals with the mathematical modeling of traffic flows on urban road networks using microscopic approach. The model is based on the cellular automata theory and presents a generalization of the Nagel-Schreckenberg model to a multilane case. The created program package allows to simulate traffic on various types of road fragments (T or X type intersection, strait road elements, etc.) and on road networks that consist of these elements. Besides that, it allows to predict the consequences of various decisions regarding road infrastructure changes, such as: number of lanes increasing/decreasing, putting new traffic lights into operation, building new roads, entrances/exits, road junctions.

An Integrated Framework for Road Detection in Dense Urban Area from High-Resolution Satellite Imagery and Lidar Data

Automatic road detection, in dense urban areas, is a challenging application in the remote sensing community. This is mainly because of physical and geometrical variations of road pixels, their spectral similarity to other features such as buildings, parking lots and sidewalks, and the obstruction by vehicles and trees. These problems are real obstacles in precise detection and identification of urban roads from high-resolution satellite imagery. One of the promising strategies to deal with this problem is using multi-sensors data to reduce the uncertainties of detection. In this paper, an integrated object-based analysis framework was developed for detecting and extracting various types of urban roads from high-resolution optical images and Lidar data. The proposed method is designed and implemented using a rule-oriented approach based on a masking strategy. The overall accuracy (OA) of the final road map was 89.2%, and the kappa coefficient of agreement was 0.83, which show the efficiency and performance of the method in different conditions and interclass noises. The results also demonstrate the high capability of this object-based method in simultaneous identification of a wide variety of road elements in complex urban areas using both high-resolution satellite images and Lidar data.

Monitoring geometric properties of an existing forest road using airborne Lidar data

Accurate information about geometric properties of a forest road is essential for the sustainable forestry and transportation safety. In this study the ability of airborne Lidar in detecting vertical and horizontal profiles and cross section elements of a forest road was investigated in a deciduous forest of Hyrcanian zone. Moreover, Lidar-derived road data was compared with field surveyed data by Leica Total Station device. The results indicated that the average error of Lidar in assessing vertical and horizontal profiles of the existing road was 0.57 m and 4.9°, respectively. The average error of Lidar in detecting the roadbed was 0.78 m. Lidar had an average error of 1.36% in assessing the longitudinal gradient. Based on findings of this study it was concluded that geometric properties of existing forest roads can be monitored rapidly under dense tree canopy using high-resolution Lidar data and without field survey.

A New Approach to Energy Calculation of Road Accidents against Fixed Small Section Elements Based on Close-Range Photogrammetry

This paper presents a new approach for energetic analyses of traffic accidents against fixed road elements using close-range photogrammetry. The main contributions of the developed approach are related to the quality of the 3D photogrammetric models, which enable objective and accurate energetic analyses through the in-house tool CRASHMAP. As a result, security forces can reconstruct the accident in a simple and comprehensive way without requiring spreadsheets or external tools, and thus avoid the subjectivity and imprecisions of the traditional protocol. The tool has already been validated, and is being used by the Local Police of Salamanca (Salamanca, Spain) for the resolution of numerous accidents. In this paper, a real accident of a car against a fixed metallic pole is analysed, and significant discrepancies are obtained between the new approach and the traditional protocol of data acquisition regarding collision speed and absorbed energy.

Building and Climbing based Visual Navigation Framework for Self-Driving Cars

This paper proposes a visual navigation strategy for self-driving car running on a constant-width road. The task is to process road image with multiple elements information for planing path and providing the basis for acceleration and deceleration. Common road elements are straight, bend, ramp and crossroad. We propose a novel navigation framework (BCVN) that explicitly decomposes the visual navigation task into navigation line extraction, deviation calculation and curvature calculation. The core idea of navigation line extraction is Building-Climbing. Building is to build foundations with a small number of consecutive points. Climbing is to climb points on the basis of the foundations. Building and Climbing are both used in search of bilateral edges. Deviation calculation use the method of dynamic weighting for self-driving car to control steering. Curvature calculation is to obtain a suitable value for self-driving car to achieve acceleration and deceleration control. We use least squares algorithm to assist in bilateral edges search and curvature calculation. We describe our real-time implementation of the BCVN framework, the method of dynamic weight and Building-Climbing. We test the strategy on the self-driving car platform, which shows strong adaptability and high efficiency.