전 세계적으로 지하도로의 건설이 활발히 이루어지고 있지만, 지하도로에서의 운전자 행태에 대한 연구는 여전히 부족한 실정이다. 또한 현재 지하도로 설계기준은 주로 지상도로나 터널 기준을 준용하고 있어, 지하 특유의 환경적 요인을 충분히 반영하지 못하고 있 다. 이에 따라, 지하도로에서의 운전자 행태를 분석하고 이를 반영한 설계기준 마련이 필요하다. 본 연구는 지하도로에서 운전자가 차로 변경을 어떻게 수행하는지 분석하고, 정보 제공 방식이 운전자 행태에 미치는 영향을 평가 하는 것을 목적으로 한다. 이를 통해, 향후 지하도로 설계 및 운영에 필요한 개선 사항을 제안하고자 하였다. 이를 위해 본 연구에서 는 소형차 전용도로의 설계 재원을 기준으로한 VR 기반 주행시뮬레이터 맵을 구성하였고 34명의 피실험자를 모집하여 주행시뮬레이 터 실험을 수행하였다. 첫 번째로 차로변경 행태를 살펴보기 위하여 현행 차로 변경 허용 구간 기준인 400m와 대안으로 차로 변경 허용 구간 2km로 비교하 여 운전자의 차로변경 행태에 대해 분석을 수행하였다. 두 번째로는 현행 정보제공 체계 기준인 분기전 2km, 1km, 150m 전 정보안내 대안과 대안으로 추가 500m 지점에 정보를 제공하는 방안에 대해 주행시뮬레이터 실험을 수행하고 대안별 효과를 비교하였다. 실험결과를 검토한 결과, 지상 도로보다 지하 도로에서 운전자들은 차로 변경을 더 어려워하는 경향이 있었다. 두 번째로 운전자들은 차로 변경 허용구간에 따른 주행패턴의 유의미한 변화는 존재하지 않는 것으로 나타났으며, 평소의 주행 습관에 따라 차로 변경을 하 는 것으로 나타났다. 세 번째로는 정보 제공 횟수를 늘릴 경우 운전자들은 차로 변경과 진출 지점을 더 빨리 결정하며, 차로 변경 지 점의 분포가 작아지는 현상이 관찰되었다. 이는 많은 운전자들이 비슷한 지점에서 차로 변경을 하게 되어 상충 구간이 줄어들고, 그에 따라 교통 안전성이 증가할 수 있음을 의미한다.

PURPOSES : As evaluation methods for road paving materials become increasingly complex, there is a need for a method that combines computational science and informatics for new material development. This study aimed to develop a rational methodology for applying molecular dynamics and AI-based material development techniques to the development of additives for asphalt mixtures. METHODS : This study reviewed relevant literature to analyze various molecular models, evaluation methods, and metrics for asphalt binders. It examined the molecular structures and conditions required for calculations using molecular dynamics and evaluated methods for assessing the interactions between additives and asphalt binders, as well as properties such as the density, viscosity, and glass transition temperature. Key evaluation indicators included the concept and application of interaction energy, work of adhesion, cohesive energy density, solubility parameters, radial distribution function, energy barriers, elastic modulus, viscosity, and stress-strain curves. RESULTS : The study identified key factors and conditions for effectively evaluating the physical properties of asphalt binders and additives. It proposed selective application methods and ranges for the layer structure, temperature conditions, and evaluation metrics, considering the actual conditions in which asphalt binders were used. Additional elements and conditions considered in the literature may be further explored, considering the computational demands. CONCLUSIONS : This study devised a methodology for evaluating the physical properties of asphalt binders considering temperature and aging. It reviewed and selected useful indicators for assessing the interaction between asphalt binders, additives, and modified asphalt binders and aggregates under various environmental conditions. By applying the proposed methods and linking the results with informatics, the interaction between asphalt binders and additives could be efficiently evaluated, serving as a reliable method for new material development.

PURPOSES : The aim of this study is to develop a road fog information system based on the geostationary meteorological satellite (GK2A) for road weather services on highways. METHODS : Three threshold values sensitive to fog intensity in the GK2A fog algorithm were optimized using multi-class receiver operating characteristic analysis to produce road fog information depending on day and night. The developed a GK2A road fog algorithm that can detect three levels of road fog based on the visibility distance criteria (1km, 500m, and 200m). Furthermore, the GK2A road fog product was not only substituted with visibility objective analysis data in unknown and cloud-covered areas of satellite data, but also integrated with visibility distance data obtained from visibility gauges and CCTV image analysis to improve the accuracy of road fog information. RESULTS : The developed road fog algorithm based on meteorological satellite data provides real-time road fog information categorized into three levels (attention, caution, and danger) based on the visibility distance, with a spatial resolution of 1km × 1km and temporal resolution of 5 minutes. The road fog algorithm successfully detected road fog in five out of seven fog-related traffic accidents reported by Korean media outlets from 2020 to 2022, resulting in a detection success rate of 71.4%. The Korea Meteorological Administration is currently in the process of installing additional visibility gauges on 26 highways until 2025, and the next high-resolution meteorological satellite (GK5) is planned to be launched in 2031. We look forward to significantly improving the accuracy of the road fog hazard information service in the near future. CONCLUSIONS : The road fog information test service was initiated on the middle inner highway on July 27, 2023, and this service is accessible to all T-map and Kakao-map users through car navigation systems free of charge. After 2025, all drivers on the 26 Korean highways will have access to real-time road fog information services through their navigation systems.

본 연구에서는 운전 시뮬레이션을 사용하여 자율주행 환경을 구현한 후 3-수준 자율주행 조건에서 자율주행 차량 (automated vehicle: AV)으로부터 운전자에게 전달되는 제어권 인수 요구(takeover request: TOR) 정보의 양상(시각, 청각 및 시각+청각) 및 도로 형태(직선도로와 곡선도로)에 따라 운전자의 제어권 인수 시간(takeover time: TOT) 및 정신적 작업부하(제어권 인수 이후에 운전자들이 경험한 주관적 작업부하와 심장박동수에서의 변화)가 어떻게 차별 화되는지 분석하였다. 본 연구의 결과를 요약하면 다음과 같다. 먼저, AV로부터 TOR이 제시된 이후 실험참가자들 이 보인 TOT에 대한 분석 결과, TOR 정보양상의 측면에서는 시각 정보가 가장 빠른 TOT를 이끌어 낸 반면 청각 정보 조건에서 가장 느렸고, 도로 형태 측면에서는 직선도로 조건에 비해 곡선도로 조건에서의 TOT가 유의하게 더 느렸으며, 특히 청각 정보 조건에서 도로 형태에 따른 TOT에서의 차이가 가장 컸다. 둘째, 정신적 작업부하에 대한 분석 결과, TOR 정보가 시각 혹은 시각+청각적으로 제시된 조건에 비해 청각적으로 제시된 조건에서 주관적 작업부 하 측정치와 심장박동수 변화 크기 모두 전반적으로 더 낮았고 특히, 심장박동수 변화의 경우 이러한 경향은 곡선도 로 조건에서만 관찰되었다. 이러한 결과는 TOR 정보의 양상과 도로 형태에 따라 운전자의 TOT와 정신적 작업부하 수준이 달라질 수 있고, 특히 TOT가 빠를수록 정신적 작업부하 수준은 상대적으로 더 높아질 수 있음을 시사한다.

PURPOSES : This study aims to examine actual cases of providing detour information in accidental situations such as traffic accidents and road construction through a VMS installed on national highways in metropolitan areas with alternative routes, as well as cases of simultaneously providing travel time information on parallel paths such as national and regular highways. For each case, we analyzed whether the provision of VMS traffic information leads to route changes and substantial effects. METHODS : To analyze traffic changes on the main and detour roads based on the detour information provided on traffic accidents in actual cases, the traffic volume and speed on the accident day were compared with those on the same days and at the same time of the day (regular days) based on the VDS data of the main and detour roads. Cases providing more detour information on road construction were investigated by examining three time periods: one week from construction initiation and one week before and after the construction period (regular days). The traffic volume and speed on the main road were compared based on the VDS data, and those on the detour road were compared based on data made available by private entities. Regarding the cases of simultaneously providing drivers with comparative information on travel time over parallel sections of national and regular highways, traffic situation changes in highways were analyzed in the following special traffic control periods (New Year's Day, NY Day), during which congestion is expected due to heavy traffic: before and after the provision of comparative information for 2015 New Year's Day and 2016 NY Day. RESULTS : The detour rate related to route changes based on the detour information for traffic accidents was 35%. On the detour route, the traffic volume increases as traffic from the main road is absorbed. However, the average travel speeds did not differ significantly. When further detour information regarding a road construction project was provided, the detour rate from the main road was 21%. The travel speeds were similar, except on the first day of construction. Almost no changes were observed in the first section of the detour. The speed slightly decreased in the second section but did not significantly hinder the traffic flow. When comparative traffic time information on parallel routes (national highways and expressways) was provided, the traffic volume increased to some extent after the report was provided for every case. However, the data frequency rate in the 5-min unit, which was still under the congestion speed standard (40 km/h), decreased. This indicates that traffic congestion was significantly relieved. CONCLUSIONS : Previous studies on detour rates or route changes based on VMS traffic information have focused on VMS instruments on expressways. Although their estimates were based on simulated situations, this study used actual VMS installed on national highways. In addition, this study utilizes the existing case records of national highway ITS centers, covering traffic situation monitoring, measures for accidental situations, etc., in regular times or special traffic control periods, as well as statistical data, including ITS real-time traffic information. The analysis results of this study accurately represent situations on actual roads and can be utilized to analyze future ITS operation and installation project effects.

PURPOSES : This study focuses on advance traffic information to prevent secondary traffic accidents on express highways. The purpose of this study is to analysis the optimal scenario by evaluating the effect of each advance traffic information scenarios using virtual driving simulation. METHODS : By designing traffic information scenarios and services with a combination of VMS and mobile PUSH notifications, driver behavior in the event of a traffic accident was analyzed. For this, a simulation environment was designed through engineering analysis. Through virtual driving simulation, the driver's deceleration point and the perception-reaction time are analyzed. RESULTS : Four scenarios were designed and reviewed so that VMS and mobile PUSH notification can be provided simultaneously after the driver drove for 5 km. As a result of driving with 30 drivers, the drivers reacted fastest when VMS was installed, followed by mobile PUSH notification, VMS+mobile PUSH notification, and NOTHING. CONCLUSIONS : When designing traffic information service, it was observed that providing information through VMS alone is more efficient than providing two services of traffic information. Therefore, it can be used as basic data for preventing secondary accidents on express highway.

PURPOSES : Since the 1990s, underground utility projects have been conducted to solve the problem of aerial communication cables. The purpose of this study is to derive optimal measures for preventing collisions with existing underground utilities and for future maintenance in the implementation of the utilities undergrounding projects. This study considered the identifier sensor and tested the optimal sensor performance for more accurate and systematic management. METHODS : In this study, three representative technologies were selected from identifier sensors generally used in air and the possibility for their use in soil and asphalt was confirmed by simulating the environment via a test construction. Three identifier sensors were selected: BLE (Bluetooth low energy) beacon, ultra-high frequency radio frequency identification (UHF RFID), and a geomagnetic recognizer. The long-term recognition performance of each identifier sensor was tested using the underground depth as a variable and the results were analyzed for comparison. RESULTS : The results of the test under limited conditions and environment demonstrated that the BLE Beacon had advantages in equipment composition, recognition range, and speed but exhibited problems with batteries in winter. The geomagnetic recognizer did not show the exact location and its influence on the surrounding environment was a disadvantage. CONCLUSIONS : Although the performance of UHF RFID has been demonstrated to be relatively suitable under these test conditions, it seems that the impact of the more diverse installation depth or medium should be reviewed for actual commercialization.

PURPOSES : The purpose of this study is to contribute to the utilization of standards while considering the possible upgrade of a local system as a subject of the application. Therefore, this study aims to explore the possible application of LandInfra for a local road management (maintenance) system in the context of enabling the basis of 3D geospatial road information management in Korea. METHODS : Based on a review of related literature and international standards, an analysis of the current system is performed. After reviewing the LandInfra standard, an examination of corresponding classes between each data model (HMS and LandInfra) is performed for the mapping process. After the mapping process, a data model of the LandInfra-based HMS pavement data model is proposed. RESULTS : To apply the LandInfa to the HMS pavement part, an examination of each data model is performed. After this procedure, a LandInfra-based HMS pavement database schema is proposed in the context of enabling 3D geospatial road information management and maintenance, particularly for pavement management information. CONCLUSIONS : This paper presents how the LandInfra international open geospatial standard can be applied to the local road management system (HMS pavement part). As a result of this study, the LandInfra standard could be applied to the HMS; however, an encoding of the standard is required for conformance. Thus, further studies would be the encoding of the proposed data model for conformance with InfaGML encoding standards. In addition, a system prototype may be needed for complete application.

PURPOSES : The Ministry of Land, Infrastructure and Transport (MOLIT) and its subordinate agencies have recently established various policies for the application of BIM and are implementing these policies, and are increasing project orders with the application of BIM. Developed countries where they have earlier adopted BIM provide BIM standards and guidelines at the national level to support BIM implementation by private-sector constructors. Domestic BIM standards and guidelines, however, have been lacking details on upper-level standards that have to be presented by ordering agencies, thereby limiting the practical application thereof. This study aims to provide BIM practice manual development measures to ensure the facilitation of the writing of BIM outputs and their delivery in the road sector. METHODS: This study first analyzed domestic BIM standards and guidelines, and examined BIM processes in the existing BIM guidelines to determine the major works required in each stage of the implementation of road construction projects. Further, the study determined those matters that were required in working BIM but were not specified in existing BIM guidelines. Those derived contents have been reflected in the definition of the configuration system in the table of contents of the BIM practice manual, and in the contents on the road sector, and the details of each configuration system have been specified. RESULTS : The proposed BIM practice manual for the road sector is a technical guide on BIM guidelines published by public ordering agencies, and provides the basic requirements and methods required for the writing of BIM models. Further, the manual provides working procedures and detailed methods for writing BIM to enable working-level staffers on BIM projects to construct BIM data. The proposed BIM practice manual was configured with considerations for domestic civil-sector BIM technology levels and will be further developed and improved according to the development of domestic BIM technology. CONCLUSIONS : In an effort to respond to the changing domestic construction technology environment, and to apply and activate BIM, this study analyzed domestic BIM standards and guidelines, and defined a working BIM manual configuration system and its detailed configuration method. The findings and improvements are presented as a BIM practice manual on development measures in the road sector. This manual is expected to minimize the repetitive trials and errors and design errors in the construction of road-sector BIM models, to improve the productivity and efficiency in the creation of BIM outputs and their delivery, and to enhance the quality and utilization of the outputs. Further, the proposed manual is expected to provide and share information on the practical cases for BIM, to bolster the capabilities of design engineering, to ensure the linkage with relevant agencies, and thus to expand the diffusion of BIM in a virtuous cycle.

PURPOSES : With the recent change to domestic and overseas construction technologies, which led to the adoption and application of threedimensional building information management (BIM), a BIM output delivery operation system is needed for the civil engineering infrastructure category. This study analyzes the domestic and overseas BIM-order placement, BIM-related guidelines/guides, and the BIM output delivery system for the road construction project category to present guideline development measures for BIM output writing and delivery. METHODS: This study surveys and analyzes the domestic BIM-related research trends to examine the domestic-infrastructure BIM-order placement situations in public ordering agencies. Additionally, it analyzes the domestic BIM-related guides and guidelines and existing twodimensional electronic delivery systems and the domestic and overseas BIM output delivery systems. This study defines the guideline composition system and direction to present criteria for BIM output writing, delivery, management, and utilization in the road category. Furthermore, it presents guideline composition measures for BIM output writing and delivery to propose detailed criteria, output-list composition, and output inspection procedures. RESULTS : This study presented BIM output guideline development measures for planning BIM output writing and delivery and management/utilization measures in the road category. To that end, it determined the domestic and overseas BIM guide and guideline composition systems, BIM ordering criteria, BIM data writing and delivery criteria, BIM output management and utilization measures, and a common BIM output list to present suitable detailed criteria. CONCLUSIONS: This study sought to respond to changes to the domestic and overseas construction environment and to present output writing/delivery guidelines as activation measures supporting the adoption and application of BIM. To that end, we analyzed the domestic and overseas BIM guidelines and guides, task instructions, bid information, etc. to define the appropriate composition system and to give it direction. We defined the contents of tables and detailed descriptions to present guideline development measures for BIM output writing/delivery guidelines in the road category. This is expected to improve work efficiency for BIM and to enhance output quality and utilization. Furthermore, the adoption of BIM in the road category will provide an infrastructure environment with which to exchange BIM information with related agencies. We plant to further develop verification tools for the Ministry of Land, Infrastructure, and Transport's BIM model projects, for their output writing and delivery, and for an integrated BIM platform that will continue to improve the proposed criteria.

PURPOSES: This research aims to estimate the occurrence of hydroplaning on roads based on the road alignment types and rainfall intensity in Seoul.METHODS: Three types of data were used for estimation of hydroplaning in this study. The Inner Circulation Road (12.5 km) to the Bukbu Expressway (7.4 km) in Seoul was selected as the test road and data was collected for road information using a probe-vehicle. Precipitation was observed from Automatic Weather System in Seoul. These data were interpolated by applying Inverse Distance Weighted Methodology for hydroplaning estimation. Finally, the water depth information of the roads was observed using an RCM411 device.RESULTS : This study demonstrated that the cross slope with small-angle-tilt or vertical section with large-angle-tilt are the primary factors causing hydroplaning on the roads. The flow velocity on steep slope is high; however, large drainage lengths result in hydroplaning on the roads.CONCLUSIONS : This result can contribute towards the reduction of car accidents on rainy days. Furthermore, information regarding hydroplaning can be delivered to drivers more rapidly and precisely in the future.

PURPOSES: The density in uninterrupted traffic flow facilities plays an important role in representing the current status of traffic flow. For example, the density is used for the primary measures of effectiveness in the capacity analysis for freeway facilities. Therefore, the estimation of density has been a long and tough task for traffic engineers for a long time. This study was initiated to evaluate the performance of density values that were estimated using VDS data and two traditional methods, including a method using traffic flow theory and another method using occupancy by comparing the density values estimated using vehicular trajectory data generated from a radar detector. METHODS: In this study, a radar detector which can generate very accurate vehicular trajectory within the range of 250 m on the Joongbu expressway near to Dongseoul tollgate, where two VDS were already installed. The first task was to estimate densities using different data and methods. Thus, the density values were estimated using two traditional methods and the VDS data on the Joongbu expressway. The density values were compared with those estimated using the vehicular trajectory data in order to evaluate the quality of density estimation. Then, the relationship between the space mean speed and density were drawn using two sets of densities and speeds based on the VDS data and one set of those using the radar detector data. CONCLUSIONS: As a result, the three sets of density showed minor differences when the density values were under 20 vehicles per km per lane. However, as the density values become greater than 20 vehicles per km per lane, the three methods showed a significant difference among on another. The density using the vehicular trajectory data showed the lowest values in general. Based on the in-depth study, it was found out that the space mean speed plays a critical role in the calculation of density. The speed estimated from the VDS data was higher than that from the radar detector. In order to validate the difference in the speed data, the traffic flow models using the relationships between the space mean speed and the density were carefully examined in this study. Conclusively, the traffic flow models generated using the radar data seems to be more realistic.

PURPOSES: While road networks are becoming increasingly complex, traffic signs are being indiscriminately installed and operated, which makes drivers who depend on traffic signs to reach their destination confused and unable to understand road information efficiently. In order to promptly and exactly guide road users to their destinations, traffic signs should be able to satisfy the functions of connectivity, visibility, and location suitability. However, the results of a site survey shows that most of the traffic signs currently installed in the Jeollanam-do Province do not satisfy these functions. METHODS: This study analyzed the problems of traffic signs after an actual site survey and focused on a total on 9,353 traffic signs and 70 road routes in Jeollanam-do Province. RESULTS : This study analyzed the problems of traffic signs based on their required functions (connectivity, visibility, suitability) and suggested improvements by establishing a guide system that considered the problems found in the study. CONCLUSIONS : The guide system can be utilized as a basic material that provides efficient road information for future installation and maintenance of traffic signs in Jeollanam-do Province.

PURPOSES : Expressways experience chronic and recurring congestion, especially during weekends and holidays, because of the increased demands for leisure-related travel. The alternatives to solve chronic and recurring congestion may be three-fold: (1) physical expansion of expressway capacities, (2) road pricing, and (3) temporal and spatial distribution of traffic demands. Among these, the third alternative may be the most cost-effective method for the Korea Expressway Corporation (KEC) that can be achieved by using the existing ITS infrastructure. METHODS : KEC initiated a pilot study in which the traffic on congested expressways was managed by providing traffic condition information (i.e., travel times) of neighboring national highways for taking detours via variable message signs (VMS). This study aimed to estimate the detour rate, and the two pilot studies on Seohaean and Yeongdong expressways yielded many benefits. RESULTS: It was revealed that the total length of congestion segments decreased by 7.8 km, and the average travel speed increased by 5.3 km/h. CONCLUSIONS: Based on these findings, it was concluded that the propagation of detour information via VMSs during congestion hours can help reduce congestion on expressways and increase the benefits of the entire network.