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Wyniki wyszukiwania dla: VEHICULAR ROADS
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Identification of transition curves in vehicular roads and railways
PublikacjaIn the paper attention is focused on the necessity to systematize the procedure for determining the shape of transition curves used in vehicular roads and railway routes. There has been presented a universal method of identifying curvature in transition curves by using differential equations. Curvature equations for such known forms of transition curves as clothoid, quartic parabola, the Bloss curve, cosinusoid and sinusoid, have...
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A Survey of Vehicular Network Systems for Road Traffic Management
PublikacjaIn this survey, we analyze the proposals of vehicular communication systems in the context of road traffic management. Starting with the definition of communications between vehicles (V2V), vehicles-to-infrastructure (V2I) and vehicles-to-everything (V2X), we first focus on the requirements and current standards for the Intelligent Transport Systems (ITS), including the maximum communication delay, the communication range and the...
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Vehicular Communication Environments
PublikacjaCommunication to and between road vehicles (cars, truck, buses, trains, etc.) are of growing interest. This is partly due to the attractive services that cooperative intelligent transport systems (C-ITSs) provides, mainly in the areas of traffic safety and traffic efficiency. An enabler for C-ITS is wireless vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, collectively referred to as vehicle-to-X (V2X)...
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Road safety strategy on national roads
PublikacjaMimo podejmowanych wielu działań w zakresie brd na sieci dróg krajowych w Polsce, rezultaty są dalekie od oczekiwań i zadań postawionych przez Krajowy Program BRD GAMBIT 2005. Można by to tłumaczyć dużym przyrostem liczby pojazdów i wzrostem pracy przewozowej szczególnie na drogach krajowych. Ale porównanie ryzyka występującego na sieci dróg krajowych w Polsce do ryzyka występującego na drogach krajowych najbliższych krajów europejskich...
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Cooperative Data Transmission in Wireless Vehicular Networks
PublikacjaThe paper presents issues related to the cooperative transmission in wireless vehicular networks. Cooperative transmission involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. The paper presents the methods used to implement cooperative transmission and the types of cooperative networks.
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Driver Fatigue and Road Safety on Poland's National Roads
PublikacjaThis paper presents an overview of factors causing driver fatigue as described in the literature. Next, a traffic crash database for 2003–2007 is used to identify the causes, circumstances and consequences of accidents caused by driver fatigue on Poland’s national roads. The results of the study were used to build a model showing the relationship between the concentration of road accidents and casualties, and the time of day. Finally,...
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Driver Fatigue and Road Safety on Poland’s National Roads
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Deep Learning-Based Intrusion System for Vehicular Ad Hoc Networks
PublikacjaThe increasing use of the Internet with vehicles has made travel more convenient. However, hackers can attack intelligent vehicles through various technical loopholes, resulting in a range of security issues. Due to these security issues, the safety protection technology of the in-vehicle system has become a focus of research. Using the advanced autoencoder network and recurrent neural network in deep learning, we investigated...
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Numerical Modeling and Simulation of Vehicular Crashes into Three-Bar Metal Bridge Rail
PublikacjaAdvanced finite element (FE) modeling and simulations were performed on vehicular crashes into a three-bar metal bridge rail (TMBR). The FE models of a sedan, a pickup truck, and a TMBR section were adopted in the crash simulations subject to Manual for Assessing Safety Hardware (MASH) Test Level 2 (TL-2) and Test Level 3 (TL-3) requirements. The test vehicle models were first validated using full-scale physical crash tests conducted...
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Roads safety programmes as an effective tool for developing system-based road safety policies
PublikacjaW sytuacji niskiego poziomu bezpieczeństwa ruchu drogowego w Polsce, dążąc do realizacji rekomendacji Unii Europejskiej, Polska przyjęła ambitny cel zmniejszenia liczby ofiar śmiertelnych wypadków drogowych o 50% w okresie 2003-2013. Osiągnięcie tego celu wymaga podjęcia skoordynowanych działań wskazanych we wcześniej przygotowanych programach bezpieczeństwa ruchu drogowego. W artykule scharakteryzowano przyjęte w tych programach...
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ON ESTIMATION OF OCCUPANT SAFETY IN VEHICULAR CRASHES INTO ROADSIDE OBSTACLES USING NON-LINEAR DYNAMIC ANALYSIS
PublikacjaThe article describes a comparison of two general methods of occupants safety estimation based on a numerical examples. The so-called direct method is mainly based on the Head Injury Criterion of a crash test dummy in a vehicle with passive safety system while the indirect method uses a European standards approach to estimate impact severity level. Numerical simulations in LS-DYNA have been conducted.
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Roads unsafety - social costs
PublikacjaThe condition of road safety has a significant impact on the quality of citizens' life. Yearly, one in a hundred families in Poland suffers because of road accidents. It is affected by them not only in material terms but first and foremost in moral terms. Road accidents are one of the main causes of degradation in the quality of life. In Poland we hardly know anything about the fate of the road traffic victims, their life problems...
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On analysis of double-impact test of 1500-kg vehicle into w-beam guardrail system
PublikacjaEvery day on roads many scenarios of accidents may occur. One of the measures to minimize their consequences is road safety barriers. Finite Element analyses are being increasingly used to support the physical testing of these devices. The paper addresses the issue of a secondary impact into the previously damaged w-beam guardrail system. This situation belongs to one of the most dangerous which can happen on roads and may cause...
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Poroelastic Material for Urban Roads Wearing Courses
PublikacjaConventional road materials used for producing wearing courses of roads are based on mineral aggregate and bituminous or Portland cement binders. The road materials must be optimized for different properties, including skid resistance, durability, rolling resistance and tire/road noise. Unfortunately, it seems that within classic technologies it is very difficult to achieve further reduction of tire/road noise. Innovative porous...
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Experiences and Challenges in Fatality Reduction on Polish Roads
PublikacjaAccording to the UN, road safety is the key to achieving sustainable development goals, yet the complexity of how road accidents happen makes this a difficult challenge leaving many countries struggling with the problem. For years, Poland has infamously been one of the EU’s top countries for road-accident fatality rates. Despite that, it has made significant progress in the last thirty years with a fatality reduction of more than...
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Poroelastic Material for Urban Roads Wearing Courses
PublikacjaConventional road materials used for producing wearing courses of roads are based on mineral aggregate and bituminous or Portland cement binders. The road materials must be optimized for different properties, including skid resistance, durability, rolling resistance and tire/road noise. Unfortunately, it seems that within classic technologies it is very difficult to achieve further reduction of tire/road noise. Innovative porous...
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The effect of trees in the road crown on road safety
PublikacjaW referacie przedstawiono problem występowania wypadków związanych z najechaniem na drzewo. Problem ten występuje w Polsce głównie w województwach północnych i zachodnich, co jest związane ze specyficznymi cechami sieci drogowej tego obszaru. Referat przedstawia negatywny wpływ drzew rosnących w koronie drogi na bezpieczeństwo ruchu drogowego oraz określa metody zapobiegania wypadkom związanym z najechaniem na drzewo. Ze względu...
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Effect of the Road Environment on Road Safety in Poland
PublikacjaRun-off-road accidents tend to be very severe because when a vehicle leaves the road, it will often crash into a solid obstacle (tree, pole, supports, front wall of a culvert, barrier). A statistical analysis of the data shows that Poland's main roadside hazard is trees and the severity of vehicles striking a tree in a run-off-road crash. The risks are particularly high in north-west Poland with many of the roads lined up with...
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An analysis of valuation principles of the properties intended for public roads
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Roads to the development of improved pertussis vaccines paved by immunology
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Risks associated with the transportation of hazardous materials on public roads
PublikacjaA significant proportion of the transport of hazardous materials is carried out on public roads. Therefore, the safety of such transport is becoming increasingly important. Every catastrophe involving hazardous materials has a negative impact on direct road users and the surrounding environment, becauses its range is mostly not local. It follows that in the event of such catastrophe, its effects should be minimized. This is possible...
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Mobile satellite measurements in designing and exploitation of rail roads
PublikacjaThe article presents a summary of several years (2009-2015) of studies on the application of mobile satellite Global Navigation Satellite Systems (GNSS) measurements in the field of designing and operation of railways. These studies have been conducted by an interdisciplinary research team from the Gdansk University of Technology and the Gdynia Maritime University. Mobile satellite GNSS measurements are taken during a ride (through...
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Comparison of road and laboratory measurements of tyre/road noise
PublikacjaTyre/road noise is one of the major environmental problems related to road traffic. There are several measuring methods of tyre/road noise that may be carried out on the road (for example Coast-down and Close Proximity Method) or in the laboratory (Drum Method). Road measurements are preferred for evaluations of pavement properties while laboratory methods are mostly used to evaluate tyres. One of the biggest problems associated...
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Tyre/road noise reduction by a poroelastic road surface
PublikacjaLow noise road surfaces of existing types may in favourable cases and in new conditions provide up to 7 dB of noise reduction. For higher noise reductions, innovative solutions must be sought. Poroelastic road surfaces (PERS) may be such a solution, which currently is studied in the EU project PERSUADE. This paper presents results of trials with a PERS version prefabricated by one of the project partners. Tests were made in a laboratory...
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Assessing the Effects of the Road Surface and Weather Conditions on Road Safety
PublikacjaWhen transport is analysed for its safe delivery the focus is mainly on assessing the safety of roads and the risk of undesired events. These include road accidents, an occurrence which is relatively rare and random. Randomness means that accidents depend on several factors which are partly deterministic (can be controlled) and partly stochastic (random and unpredictable). The set of crash contributing factors can be classified...
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Construction of Public Roads at the Meeting Point of Different Legislation Systems
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The Study of Geometry of the Selected Transition Curves in the Design of Circular Roads
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Transition curve with smoothed curvature at its ends for railway roads
PublikacjaIn the paper, in view of a railway ballasted track, a new concept of transition curve of linear form of curvature along its length and smoothed extreme regions is presented. For this purpose use has been made of an original, universal method for identifying transition curves by means of differential equations. Some general curvature equations for three regions investigated have been determined to be followed by appropriate parametric...
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Analysis of Factors Influencing the Density of Fatalities on National Roads in Poland
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The application of risk analysis in the assessment and management of road safety in road tunnels
PublikacjaTunele drogowe są najbardziej wrażliwymi za zakłócenia, spowodowane wypadkami drogowymi, elementami sieci drogowej. Najpoważniejszymi wypadkami w tych obiektach są zdarzenia z udziałem samochodów ciężarowych przewożących materiały niebezpieczne. Od kilku lat zatem rozwijane są w Europie metody analizy ryzyka i budowane narzedzia do zarządzania ryzykiem w tunelach drogowych. W Polsce zaczyna się budować tunele drogowe, a problem...
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Tyre/road noise reduction of poroelastic road surface tested in a laboratory
PublikacjaA so-called poroelastic road surface (PERS) is being developed in Europe. This contains a large percentage of rubber particles mixed with hard aggregate (stone and sand) and bound with polyurethane. This gives high air void content (around 30 %), high elasticity and smooth texture, all of which should give low noise properties. Inthis experiment anominally 30 mm thick sample of PERS was mounted on a steel drum. Various car tyres...
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Road safety inspection as a tool for road safety management – the polish experience
PublikacjaIn Poland, road inspections were implemented in June 2014 on all national roads. Previously conducted traffic surveys mainly related to the technical condition of roads, signs and markings; other safety issues were overlooked. The main problem that occurs during inspection is an inspector’s subjective qualitative assessment which affects the classification of the sources of hazard on the road.. The paper presents an analysis of...
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Tire/Road Noise On Poroelastic Road Surfaces - Results Of Laboratory Measurements
PublikacjaTire/road noise is the most important part of traffic noise for medium and high speed driving both in the case of passenger cars and trucks. The potential to make modification of tires that significantly reduce tire/road noise in nearly over, at least for conventional tires so the only promising action is to improve road pavements. One of the innovative solutions is poroelastic road pavement (PERS) that reduces airflow related...
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The effect of road restraint systems on the level of road safety - Polish experience
PublikacjaRoadside accidents happen when a vehicle runs off the road. The majority of these accidents are very severe because leaving the road is usually followed by hitting a solid obstacle (tree, pole, support, culvert front wall, barrier). Roadsides are some of the most important issues of road safety. They have been studied for years to identify roadside hazards and the effectiveness of road safety measures such as restraint systems....
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Poroelastic Road Surface – a Promising Road Traffic Noise Abatement Solution
PublikacjaRoad surfaces have a direct impact on the generation of noise by rolling tyres, the main and dominant source of noise of moving vehicles, as well as may affect propagation of noise emitted by all noise sources of a vehicle. Thus there is no doubt that pavement should be considered as one of the major potential road traffic noise abatement measure. Low noise pavements of existing types may in new conditions provide up to 8 dB of...
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The Application of Risk Analysis in the Assessment and Management of Road Safety in Road Tunnels
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External loads for multihull watercraft
PublikacjaDla jednostek pływających wielokadłubowych sformułowano ogólne różniczkowe równania ruchu związane z możliwymi ruchami konstrukcji oceanotechnicznej. Są to ruchy związane ze stopniami swobody konstrukcji na sfalowanej powierzchni morza. Dla możliwych ruchów konstrukcji podano ogólne wzory na obciążenia zewnętrzne związane z reakcjami hydrodynamicznymi, siłami tłumienia oraz reakcjami hydrostatycznymi.
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Pedestrian Safety at Midblock Crossings on Dual Carriageway Roads in Polish Cities
PublikacjaRoad crossings across two or more lanes in one direction are particularly dangerous due to limited sight distance and high vehicle speeds. To improve their safety, road authorities should provide safety treatments. These may include additional measures to reduce speed and narrow the road cross-section and the introduction of active pedestrian crossings. Equipped with flashing lights activated automatically when a pedestrian is...
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Speed management on local government managed roads – research, recommendations and guidelines
PublikacjaCommissioned by the National Road Safety Council Secretariat, the project “Guidelines for speed management on local government managed roads” studied car driver be haviour when subjected to selected speed management measures such a local speed restrictions, surveillance, traffic calming and restricted speed areas. In addition, analyses were conducted on the impact of selected me asures...
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State of Development of Intelligent Transport Systems Services on National Roads in Poland
PublikacjaIn recent years we can see intensifying implementation of Intelligent Transport System (ITS) measures in Polish cities and on national roads. The architecture of the National Traffic Management System (KSZR) will enable the implementation of a uniform, integrated and intelligent ICT system to launch ITS systems that are the most important for drivers and the General Directorate for National Roads and Motorways (GDDKiA). This paper...
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Analysis and design improvement of high class roads’ arched sections in Poland
PublikacjaAlthough Polish road network standards, in particular higher classes of roads are improving dynamically the number of fatalities on the network is still higher that EU’s average. Ensuring road safety and high maintaining standards is a complex issue and one that poses a major challenge for all road authorities. Road accidents at high speed roads characterize specially serious material and social consequences, thus research into...
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Pedestrian on footbridges, vertical loads and response
PublikacjaThe paper is a synthesis of the experimental and theoretical investigations on dynamics of pedestrian bridges under vertical load The subject is divided into four issues.1) The pedestrian as a vertical dynamic load on footbridges, theoretic load function for walking and crouching.2) Crowd walking on the footbridge - pedestrian flow.3) Vertical lock-in effect.4) Response of the footbridge - numeric and side test results, -...
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Identifying the Effects of Selected Road and Roadside Parameters on Road Safety Using Geodetic Techniques
PublikacjaThe paper will present techniques that can be used to obtain data on road alignment and profile including the roadside. In-the-field and simulation studies have helped to develop mathematical models that integrate vehicle position data. The experiments were conducted in a virtual environment using the software ArcGIS that reflects the actual roadside conditions. The site tests were made using a purpose-built device which integrates...
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Temperature influence on tyre/road noise on poroelastic road surface based on laboratory measurements
PublikacjaThe temperature effect on measured tyre/road noise is very important phenomena as it may lead to significant errors in measurement results due to substantial influence of this parameter on the obtained values. It depends mainly on the particular tyre-road combination. It is different for dense and porous as well as for bituminous and cement concrete pavements. It differs also depending on tested tyre. The correction procedure for...
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Road safety system in Poland
PublikacjaCelem niniejszego artykułu jest przedstawienie kluczowych dla poprawy brd elementów diagnozy stanu i systemu bezpieczeństwa w Polsce, które jednocześnie mogłyby wejść w zakres działań objętych Projektem ZEUS. Ocenę diagnozy wykonano poprzez porównanie z wzorcami z tych krajów, które od lat uważa się za liderów w zakresie bezpieczeństwa.
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Monitoring system of the road embankment
PublikacjaThe paper presents the monitoring system of the embankment supported on concrete columns and overlaid by a load transfer platform (LTP) with the embedded steel grid. This field investigation was to study the complex inter-action between the columns, the LTP layer, and steel reinforcement via full-scale in situ measurements during erection of the embankment. The study was focused on the behaviour of steel reinforcement and the behaviour...
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MONITORING SYSTEM OF THE ROAD EMBANKMENT
PublikacjaThe paper presents the analysis of the monitoring system of the embankment supported on concrete columns and overlaid by a load transfer platform with the embedded steel grid. This field investigation was to study the complex interaction among the columns, the load transfer platform layer, and steel grid via in situ measurements during erection and live loading of the embankment. The study was focused on the behaviour of steel...
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The searchlight problem for road networks
PublikacjaWe consider the problem of searching for a mobile intruder hiding in a road network given as the union of two or more lines, or two or more line segments, in the plane. Some of the intersections of the road network are occupied by stationary guards equipped with a number of searchlights, each of which can emit a single ray of light in any direction along the lines (or line segments) it is on. The goal is to detect the intruder,...
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Tyre/road noise of passenger car tyres, including tyres for electric vehicles - road measurements
PublikacjaThe paper presents the results from CPX measurements of tyre/road noise performed for selected passenger car tyres, including the tyres especially designed for electric vehicles. The tyres have been measured when rolling on several typical road surfaces in Norway and in Poland. In addition, the tyres have been measured on some very low noise road surfaces, such as a the poroelastic road surface (PERS). The measurement results...
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Numerical studies on the influence of selected construction features and road conditions on the performance of road cable barriers
PublikacjaCable barriers are commonly used on Polish roads, including motorways and local roads. Their main elements are pre-stressed wire ropes, which are usually anchored at two ends in concrete blocks buried in the soil. In this work numerical studies concerning the influence of selected construction features and parameters of the vehicle motion on the performance of cable barriers were performed. Numerical simulations are a useful tool...