A Semi-Automatic Method for Identifying Defects on Road Surfaces

This paper reviews techniques on identification of road distress. The main key of this paper is to identify road distress and types of road distress. A literature reviews on the types of distress, detection techniques and methods used to identify road distress are presented. Hence, the advantages and disadvantages of current techniques such as laser scan, mobile mapping, stereo camera and uses of UAV used for road distress identification were to be out and gap in their techniques was identified. For many years, broad research has been conducted on road distress detection in order to maintain road surface to a high standard. Quick and accurate detection is required to maintain the road maintenance. A method using 2D images with supported 3D information is one of the best ways to get accurate results on identifying road distress. To keep up with the current technology, UAV with mounted camera is recommended to be used in order to provide quick and effective data capturing.

A review of monitoring systems of pavement condition in paved and unpaved roads

Like many provincial and municipal agencies, the British Columbia Ministry of Transportation (BCMoT) contracts out the collection of pavement surface condition data. Because BCMoT is committed to contracts with multiple private contractors, quality assurance (QA) plays a critical role in ensuring that the data are collected accurately and repeatably from year to year. Comprehensive QA testing procedures for surface distress data have been developed and implemented since the data collection has been based on visual ratings with event boards. Control sites that are manually surveyed are used to evaluate whether the contractor is correctly applying the BCMoT pavement surface distress rating system. To date, the QA testing has been based on a composite-index–based criterion for assessing the level of agreement and supplemented with the detailed severity and density rating data. However, the use of a composite index presents some limitations related to the model formulation and weightings assigned to particular distress types. Although the detailed ratings are useful as a diagnostic tool to pinpoint discrepancies, in the disaggregated format, they are not conducive as acceptance criteria for QA testing. Not widely used in the field of engineering, Cohen’s weighted kappa statistic has been applied since the 1960s in other areas to assess the level of agreement beyond chance among raters. The statistic was therefore identified as a possible solution for improving the ministry’s QA surface distress testing process by providing an overall measure of the level of agreement between the detailed manual benchmark survey and the contractor severity and density ratings. The application is described of Cohen’s weighted kappa statistic for visual surface distress survey QA testing using the BCMoT survey and testing procedures as a case study.

The asphaltic pavement is often subjected to various types of distress during the service life caused by excessive load, construction practices, deficient materials, and environmental conditions. A lot of pavements may occur due to moisture damage because of the presence of water on the pavement's surface, which affects the pavement's service life. It needs periodic maintenance, which requires materials and money. So many countries take the economic side by reusing old, damaged pavement and mixed with new materials in addition to its sustainable benefits, the old material called reclaimed asphalt pavement (RAP). This study examines the effect of adding RAP on durability indicators, including tensile strength ratio, retained Marshall Stability, and durability Index, in addition to prediction statistical models for reclaimed asphalt pavement mixtures in terms of durability indicators. To achieve the goals of this study, the asphalt mixtures are designed according to the superpave system; the samples are compacted by a superpave gyratory compactor with a diameter of 100 mm and prepared with (6%, 13%, 19%, and 25%) RAP content with three conditioning periods of (1, 3, and 7) days and two aging periods (short term aging for loose mixture at 135˚C for 4 hours long term aging for 120 hours at 85˚C), and two testing temperature of 25˚C and 60˚C. The results indicated that stability increased as the RAP content increased compared to the control mix, and indirect tensile strength increased with RAP addition for both aging periods. Also, results illustrated that the tensile strength ratio for specimens tested at 25˚C is higher than that tested at 60˚C temperature.

In this thesis, concepts for developing Spatial Data Infrastructures with an emphasis on visualizing 3D landscape and city models in distributed environments are discussed. Spatial Data Infrastructures are important for public authorities in order to perform tasks on a daily basis, and serve as research topic in geo-informatics. Joint initiatives at national and international level exist for harmonizing procedures and technologies. Interoperability is an important aspect in this context - as enabling technology for sharing, distributing, and connecting geospatial data and services. The Open Geospatial Consortium is the main driver for developing international standards in this sector and includes government agencies, universities and private companies in a consensus process. 
\n3D city models are becoming increasingly popular not only in desktop Virtual Reality applications but also for being used in professional purposes by public authorities. Spatial Data Infrastructures focus so far on the storage and exchange of 3D building and elevation data. For efficient streaming and visualization of spatial 3D data in distributed network environments such as the internet, concepts from the area of real time 3D Computer Graphics must be applied and combined with Geographic Information Systems (GIS). For example, scene graph data structures are commonly used for creating complex and dynamic 3D environments for computer games and Virtual Reality applications, but have not been introduced in GIS so far. 
\nIn this thesis, several aspects of how to create interoperable and service-based environments for 3D spatial data are addressed. These aspects are covered by publications in journals and conference proceedings. The introductory chapter provides a logic succession from geometrical operations for processing raw data, to data integration patterns, to system designs of single components, to service interface descriptions and workflows, and finally to an architecture of a complete distributed service network.
\nDigital Elevation Models are very important in 3D geo-visualization systems. Data structures, methods and processes are described for making them available in service based infrastructures. A specific mesh reduction method is used for generating lower levels of detail from very large point data sets. An integration technique is presented that allows the combination with 2D GIS data such as roads and land use areas. This approach allows using another optimization technique that greatly improves the usability for immersive 3D applications such as pedestrian navigation: flattening road and water surfaces. It is a geometric operation, which uses data structures and algorithms found in numerical simulation software implementing Finite Element Methods. 
\n3D Routing is presented as a typical application scenario for detailed 3D city models. Specific problems such as bridges, overpasses and multilevel networks are addressed and possible solutions described. The integration of routing capabilities in service infrastructures can be accomplished with standards of the Open Geospatial Consortium. An additional service is described for creating 3D networks and for generating 3D routes on the fly. Visualization of indoor routes requires different representation techniques.
\nAs server interface for providing access to all 3D data, the Web 3D Service has been used and further developed. Integrating and handling scene graph data is described in order to create rich virtual environments. Coordinate transformations of scene graphs are described in detail, which is an important aspect for ensuring interoperability between systems using different spatial reference systems. The Web 3D Service plays a central part in nearly all experiments that have been carried out. It does not only provide the means for interactive web-visualizations, but also for performing further analyses, accessing detailed feature information, and for automatic content discovery.
\nOpenStreetMap and other worldwide available datasets are used for developing a complete architecture demonstrating the scalability of 3D Spatial Data Infrastructures. Its suitability for creating 3D city models is analyzed, according to requirements set by international standards. A full virtual globe system has been developed based on OpenStreetMap including data processing, database storage, web streaming and a visualization client.
\nResults are discussed and compared to similar approaches within geo-informatics research, clarifying in which application scenarios and under which requirements the approaches in this thesis can be applied.
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Measurement and Rate Correction of the QT Interval

Jugular Venous Flow Quantification Using Doppler Sonography

Preservation, maintenance and rehabilitation of pavements need continuous information through monitoring for their assessment. The deterioration rate of the pavement surfaces in developing countries like India is more due to a sudden rise in the automation industry which was not thought of during the planning stage of the road network. Increase in motorized vehicles has led to early failure of the roads which need to be properly maintained by carrying out the maintenance work to have a longer service life. Pavement Information System (PIS) is a valuable tool for evaluating the rapid deterioration of roads. PIS stores and compiles a large amount of data that are frequently collected on a timely basis. The new era of the pavement information system is utilizing the Remote Sensing and Geographical Information System. The present study analyzes the major pavements in Nagpur city. For these selected roads, the different types of distress conditions on the roads were collected and were represented on the high-resolution satellite map. From these data sets, a Spatial Pavement Information System (SPIS) was developed for Nagpur road network using ArcGIS software. The management system involved the development of distress indices which were calculated based on the frequency and types of distress. The different pavements were then prioritized based on distress indices for maintenance scheduling. This research paper provides a spatial method which helps prioritize pavements for maintenance and rehabilitation to improve Level of Service of the road.

Asphalt pavements form an integral part of any transportation system. The structural capacity of the hot mix asphalt concrete layers depends on many factors including its temperature. Moreover, temperature can be a major contributor to several types of distresses. Therefore, temperature is a significant factor that affects the performance and life span of a pavement. The Libyan road network expanded at a phenomenal pace from approximately 1500 km of paved roads in 1970 to morethan 100,000 km in 2008. Brak region is located on the southern east of Libya at latitude (27°31'N) in the desert. With the recent SHRP and LTTP research findings, it was necessary to investigate the applicability of the models developed from these research studies to Brak's environmental conditions and more generally to the rest of Libyan desert reigions. This paper presents the research undertaken to develop models to predict high and low asphalt pavement temperatures in the Brak region . A pavement monitoring station was set-up in Brak to monitor air and pavement temperatures in different depth, wind speed and solar radiation. Data were collected for 365days. Daily minimum and maximum temperatures were recorded. A regression analysis was used to develop the minimum and maximum pavement temperature models, using air temperature, wind speed and solar radiation. This paper presents a new model for predicting maximum and minimum surface pavement temperature based on data collected by installed pavement monitoring station set-up at the Brak region.

Ice formation on roads leads to a higher incidence of accidents and increases winter de-icing/anti-icing costs. This study analyzed 3 years (2019–2021) of Road Weather Information System (RWIS) sub-hourly measurements collected by the Montana Department of Transportation (MDT) to understand the first-order factors of road ice formation and its mechanisms. First, road ice is formed only when the road pavement surface temperature is equal to or below the freezing point (i.e., 32 °F (i.e., 0 °C)), while the corresponding 2 m air temperature could be above 32 °F. Nevertheless, when the road pavement was below 32 °F ice often did not form on the roads. Therefore, one challenge is to know under what conditions road ice forms. Second, the pavement surface temperature is critical for road ice formation. The clear road (i.e., with no ice or snow) surface pavement temperature is generally warmer than the air temperature during both day and night. This feature is different from a natural land surface, where the land skin temperature is lower than the air temperature on cloud-free nights due to radiative cooling. Third, subsurface temperature, measured using a RWIS subsurface sensor below a road surface, did not vary as much as the pavement temperature and, thus, may not be a good index for road ice formation. Fourth, urban heat island effects lead to black ice formation more frequently than roads located in other regions. Fifth, evaporative cooling from the water surface near a road segment further reduces the outlying air temperature, a mechanism that increases heat loss for bridges or lake-side roads in addition to radiative cooling. Additionally, mechanical lifting via mountains and hills is also an efficient mechanism that makes the air condense and, consequently, form ice on the roads. Forecasting road ice formation is in high demand for road safety. These observed features may help to develop a road ice physical model consisting of functions of hyper-local weather conditions, local domain knowledge, the road texture, and geographical environment.

The driving mechanism of cement hydrated products leaching on as-built cement concrete bridge deck pavements

고속도로 이용차량의 증가와 함께 차량의 대형화와 고속화로 인해 고속도로 교통 소음레벨이 높아지고 있으며 저소음 포장노면 및 방음시설 설치 요청도 급격하게 증가하고 있다. 따라서 고속도로 교통소음으로 인한 민원예방과 함께 효율적이고 경제적인 소음저감 대책을 수립하기 위해서는 정확한 소음 예측 기술 마련이 필요하다. 본 연구에서는 시험도로에 포설된 다양한 포장노면에 대해서 CPX(Close Proximity Test) 및 Pass-by 소음 계측 방법을 혼용한 소음 계측 데이터를 이용하였고 차종별 단독 주행 시험을 실시하여 차량 및 노면별 음향파워레벨 산정식이 마련된 데이터를 이용하였다. 아울러, 상기 산정식의 정확성을 검증하기 위하여 고속도로 12개 지점에 대한 총 38회의 소음 계측한 데이터를 이용하여 해당 지점에 대한 소음 예측 모델을 구성하여 측정값과 예측값을 비교 평가하였다. 최종적으로 3차원 GUI 기능을 지원하는 도로교통 소음 예측 프로그램 KRON(Korea Road Noise)을 개발하였다. 이와 더불어 각 포장형태별 및 차종별에 따른 소음특성을 분석하였다. Domestic economic development, industrialization, and urbanization have brought along not only increased highway traffic but also elevated traffic noise levels. Thus, it is necessary to accurately predict the traffic noise levels in order to address the public demand of alleviating the noise levels in urban areas. In this study, the method of evaluating the sound power level of road traffic was investigated in terms of considering the types of road surface and vehicle, based on previous researches. Regarding CPX (Close Proximity Test) and Pass-by test, the measured noise data of Test Road of Korea Highway Corporation were utilized in order to construct the database of sound power levels of various vehicles. Specifically, the 38 noise measurement and analysis in 1/1-octave band frequencies at 12 pre-selected sites were carried out, considering topography and road surface. Finally, the comparison study was conducted between predicted and measured data in terms of traffic noise. The traffic noise prediction was based on the KRON (Korea Road Noise) program, which was developed being equipped wit 3-dimensional GUI. In addition, the traffic noise characteristics were evaluated in terms of vehicle types and pavement surface conditions.

The purpose of this study is to investigate the validity of slide-friction measurement on winter roads by the MASS vehicle from joint tests using a slide friction-measurement bus with an instrument-embedded wheel mounted to its body (5th wheel bus) and to investigate the effect of physical properties of the snow/ice on a road surface on the sliding friction coefficient.It is concluded that the sliding friction coefficient by the MASS vehicle agrees with that by the 5th wheel bus on horizontal roads, and that the effect of road inclination on the sliding friction coefficient is negligible for the MASS vehicle but significant for the 5th wheel bus. Moreover, it is found from an indoor experiment and the present field tests that the value of sliding friction coefficient depends on the height of the sherbet layer on a road surface. In case of the no contact of tires and pavement surface because of a deep sherbet layer, the sliding friction coefficient decreases with the increment of the mass ice content in the sherbet.

Preliminary study on the correlation between two-dimension surface texture and friction

Current road lighting standards and recommendations are based on luminance levels and luminance distributions on the road surface. The luminance of the road surface depends on the amount of light falling on it and the reflection properties of the road surface. Using light aggregate for road surface pavements, significant energy savings in road lighting could be achieved due to significantly higher reflectance properties of the surface. In this study several experimental pavement samples with light surface characteristics were manufactured and their reflection properties were measured. The results indicate that lighter pavement materials result in higher average road surface luminance values and lower average lighting energy usage costs per kilometer.