Equipment Condition for Zebra Crossing Night-Time Safety Performance in Latvia

According to road traffic accident (hereinafter referred to as RTA) statistics, the vulnerable road users are pedestrians in Latvia. The aim of this study is to investigate and analyse technical equipment used on non-signalled pedestrian crossings (zebra crossings) in Latvia and to make suggestions for measures that would increase road traffic safety on zebra crossings. RTAs involving collisions with pedestrians were filtered from the Ministry of the Interior database for a three-year period from 2016 to 2018. Thirty-two zebra crossings with a higher number of accidents with pedestrians were observed on the spot during the daylight and at night in several cities of Latvia. The main emphasis during the observation was placed on traffic signs and zebra road marking performance. Pedestrian crossings were observed from car driver’s view by taking photographs during day-time and night-time observations. Most attention was paid to road sign and road marking visibility from driver’s seat position. Retroreflection coefficient R’ was measured for each pedestrian crossing road sign. It was found that the condition and performance of traffic organisation equipment were not maintained on a regular basis and the life cycle of some traffic signs had well expired. Many road signs do not comply with minimum requirements, and road markings have weak visibility during wet weather conditions. It is recommended to improve visibility of pedestrian crossings from driver’s view in the urban areas by increasing rain vision for road markings and higher retroreflection class for traffic signs.

CHARACTERISATION OF LUMINESCENT ROAD MARKINGS

Photoluminescent paints for road marking have been evaluated through laboratory measurements and visibility computations. The luminance decay in the dark was measured after constant excitation during at least six hours. To study the effect of night-time lighting conditions, luminance was also measured under a constant low illumination simulating moon and light pollution, and a periodic lighting simulating automotive traffic. Measurements were also carried out on luminescent road markings applied in a full scale mock up. Then, possible uses and limits of photoluminescent road markings were investigated through visibility computations based on the COST 331 model. Findings suggest that luminescent road markings could strengthen the visual guidance of drivers on the road with traffic by increasing the visibility distance beyond the range of the headlamps during the first few hours of the night, but it depends on the night-time illumination level.

Camera-Based Lane Detection—Can Yellow Road Markings Facilitate Automated Driving in Snow?

Road markings are beneficial to human drivers, advanced driver assistance systems (ADAS), and automated driving systems (ADS); on the contrary, snow coverage on roads poses a challenge to all three of these groups with respect to lane detection, as white road markings are difficult to distinguish from snow. Indeed, yellow road markings provide a visual contrast to snow that can increase a human drivers’ visibility. Yet, in spite of this fact, yellow road markings are becoming increasingly rare in Europe due to the high costs of painting and maintaining two road marking colors. More importantly, in conjunction with our increased reliance on automated driving, the question of whether yellow road markings are of value to automatic lane detection functions arises. To answer this question, images from snowy conditions are assessed to see how different representations of colors in images (color spaces) affect the visibility levels of white and yellow road markings. The results presented in this paper suggest that yellow markings provide a certain number of benefits for automated driving, offering recommendations as to what the most appropriate color spaces are for detecting lanes in snowy conditions. To obtain the safest and most cost-efficient roads in the future, both human and automated drivers’ actions must be considered. Road authorities and car manufacturers also have a shared interest in discovering how road infrastructure design, including road marking, can be adapted to support automated driving.

Research of algorithms for road marking recognition in the lane departure warning system

The way to improve the safety of vehicles using ADAS systems has successfully proved itself in practice. The use of ADAS systems in vehicles is mandatory in many countries of the world and is accepted at the state level. One of the most widely used ADAS systems is the Lane Departure Warning System (LDWS). The paper describes the principles of operation of existing LDWS in the segment of light commercial vehicles (LCV). The algorithm and structure of the developed LDWS for the GAZelle Next vehicle are presented. The description and analysis of algorithms for recognition of road markings are given. The results and comparative analysis of virtual and road tests of the LDWS are presented. Conclusions are given on the operation of the system and the algorithm for recognizing road markings.

ANALYSIS OF TECHNICAL REQUIREMENTS AND TEST METHODS FOR ROAD MARKING MATERIALS ACCORDING TO UKRAINIAN AND EUROPEAN STANDARDS

Introduction. The current stage of the road sector development is characterized by the increased demand in the road marking. For the arrangement of road marking, various materials are used: paint, retroreflective glass beads, plastics of cold and hot application, polymer strips, prefabricated items, etc. Each material has its own set of unique characteristics related to durability, retroreflectivity, cost of application and life cycle. Problem statement. Due to the expansion of the production range of road marking materials, their choice becomes a difficult task and it should be carried out while taking into account the following requirements: normative distances of visibility must be ensured in all weather conditions 24 hours a day; long-term preservation (resistance to environmental impacts); road marking must not interfere with the vehicles movement, it should foster gliding. In order to properly select the road marking materials, the road traffic level and the predicted operation life cycle should be taken into account. For optimal selection, it is primarily necessary to review the quality characteristics of the materials through the testing of their physical, mechanical, technological and functional characteristics. Commonly, the roads owners require the quality requirements for the materials in accordance with the European standards. Objective. To compare technical requirements and methods of testing materials for road marking in accordance with the European standards. Materials and methods. Analysis of current Ukrainian and European standards for technical requirements and methods of testing the road marking materials. Results. Technical requirements for road marking materials and methods of their testing which are lacking in the Ukrainian standards are considered. A list of equipment for the required tests according to the European standards is given. Conclusions. Basing on the analysis results, it can be noted that in order to ensure the compliance of the Ukrainian laboratories abilities to check the quality of technical characteristics of materials according to the European standards, the new equipment should be provided (Tregers device, Stormer videometer, X-ray fluorescence analyzer, wear test bench and others) as well as mastering the new testing methods. Due to the high cost of the devices and equipment (for example, of the wear test bench), it is necessary to build the test sites on the roads or establish contacts with the European laboratories on the possibility of transferring the samples of materials to them for testing.

Study of Relaxation Processes in Biopolymers Using the Example of Rosin

Rosin, or colophony, and composite materials, which consist of components based on rosin and rosin products, are extensively used in various industries, in particular, as one of the main components of the composite materials for road marking. At the same time, little research has been done to study of the physicomechanical and associated physicochemical characteristics of these materials, the influence on these characteristics of the internal bounding surface of the components in wide temperature ranges and in the dynamic mode of external deforming effects.