• Korean Journal of Construction Engineering and Management
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• v.24 no.1
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• pp.31-39
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• 2023

To reduce facility management costs and safety concerns due to aging of facilities, it is important to estimate the future facilities' condition based on facility management data and utilize predictive information for management decision making. To this end, this study proposed a methodology to estimate facility elements' condition using XGBoost. To validate the proposed methodology, this study constructed sample data for road bridges and developed a model to estimate condition grades of major elements expected in the next inspection. As a result, the developed model showed satisfactory performance in estimating the condition grades of deck, girder, and abutment/pier (average F1 score 0.869). In addition, a testbed was established that provides data management function and element condition estimation function to demonstrate the practical applicability of the proposed methodology. It was confirmed that the facility management data and predictive information in this study could help managers in making facility management decisions.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.33-43
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• 2003

In South Korea, about 74% of total area is mountainous terrain It is therefore inevitable to make tunnel or cutting slope for road construction. According to a related survey, approximately 2,400 sites of cutting slopes were found from 24 different routes of roadway which is overall 900 km long, implying 2.7 slopes per 1km of roadway on average. Even though safety matter such as the slope failure prevention would be the most important consideration for the construction of cutting slopeslandscape of sloped face is nowadays becoming another important factor due to the growing demand for the driver-friendly road environment Various construction methods which attain this goal should therefore be considered in the design stage of the roadway. The objective of this study is to identify important factors in landscape of sloped-cut roadway using factor analysis. For this, 10 main treatment methods of sloped-cut fact were analyzed. This study employed the LISREL(structural analysis of common variance) model in order to capture the qualitative characteristics of the slope-cut road and examine the relationship between the suey error and the variable(s). As a result, more reasonable landscape evaluation model for the road design and construction was proposed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.395-402
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• 2010

The seriousness of a traffic accident appears relatively higher on the curve sections compared with the straight sections due to a change in speed caused by a change in the driver's sight. In particular, the visual distortion phenomenon, one of the dangerous factors taking place on the curve sections, appears different according to the road's geometric design. Although it is a genuinely principal design factor which should be necessarily considered in designing a road, the previous researches on establishing the design standards for it have been insufficiently conducted. As a result, the establishment of the road design standards for the curve sections considering the sight distortion phenomenon is desperately required. This research examined the previous researches on the driver's behaviors, the driver's sight characteristics and the perceived curve radius on the curve sections, and developed the theoretical model of perceived curve radius to which a mathematical technique is applied in consideration of the visual distortion phenomenon on the two-lane curve sections in a local area. In addition, after the theoretical visual distortion was calculated on the basis of the theoretical model of perceived curve radius, the range of error on the theoretical recognition radius model formula was verified through comparing it with the previous researches' experiential visual distortion level and analyzing both of them. As a result, it was observed that as the curve radius practically increases in the theoretical recognition curve radius, the range of error tends to go down, which reflects well the characteristics of the curve sections on the road. Based on this research, it is expected that this research will be helpful to eliminate the safety defects when designing the curve sections and contribute to develop the road design standards considering human factors in the future.

• International Journal of Highway Engineering
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• v.10 no.1
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• pp.97-104
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• 2008

Many atypical structures on the roadside are exposed to traffics unshielded posing great danger. One way to shield an atypical structure to secure the occupant safety is to stack energy absorbing material modules in front of the structure. This paper presents the analysis method of module type crash cushion made of EPS blocks using simple energy balance of the car and crash cushion and numerical examples for 0.9ton-500km/h, 0.9ton-60km/h and 0.9ton-70km/h impact are presented. This method gives simple estimation of maximum acceleration, time of crash, whether or not the vehicle stops completely before whole cushion is being crushed. However, since the acceleration and velocity data from the analysis is so crudely spaced that calculation of safety indices such is RA and OIV is not possible. Problem is overcome by using data interpolation. The spline and linear interpolation is introduce and safety analysis is made and the results are compared.

• Journal of Environmental Impact Assessment
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• v.33 no.2
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• pp.74-83
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• 2024

This study aims to estimate roadkill occurrences and investigate influential factors in Chungcheongnam-do, contributing to the establishment of roadkill prevention measures. By comprehensively considering weather, road, and environmental information, machine learning was utilized to estimate roadkill incidents and analyze the importance of each variable, deriving primary influencing factors. The Gradient Boosting Machine (GBM) exhibited the best performance, achieving an accuracy of 92.0%, a recall of 84.6%, an F1-score of 89.2%, and an AUC of 0.907. The key factors affecting roadkill included average local atmospheric pressure (hPa), average ground temperature (℃), month, average dew point temperature (℃), presence of median barriers, and average wind speed (m/s). These findings are anticipated to contribute to roadkill prevention strategies and enhance traffic safety, playing a crucial role in maintaining a balance between ecosystems and road development.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.37-46
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• 2021

Government agencies, such as police and local governments, strive to prevent traffic hazards and create a comfortable road environment by pormoting transportation and road facilities. To this end, roads and transportation facilities are enhanced and adjusted, and improvement projects in areas with frequent traffic accidents are carried out. Usually, improvement projects in areas with frequent traffic accidents vary by projects and region. Moreover, these projects are carried out under the supervision of a person in charge and related parties. Hence, civil complaints and subjectivity are reflected in deriving priorities for the improvement projects, limiting the efficiency of the project. To this end, a study was conducted to estimate the direction of improvement of the project target site. This study comprehensively considered road, traffic, and accident conditions of representative projects with high effectiveness in handling traffic accidents. The results of the study state that the accuracy of estimating the improvement project was around 88%. In addition, the study found that there was a strong relationship between traffic volume, accident rate, and accident severity in estimating the improvement direction.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.367-372
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• 2004

Highway have to be constructed under thorough investigation about function, economy, safety of the traffic and environment, because they are needing huge budget for construction and management as important facilities of the social overhead capital in the national economics. Initially the construction of roads becomes effective the plan, the design, construction phase. The design is foundation of accomplishment of the roads operation, the results of the design operation come to much effect a nation when using roads. Especially ancient design methods were not expected for visual effects as attaching weight to 2-dimensional drawing from flat. Therefore, it is difficult to recognize troubles happened during the work operation besides, many troubles are solved by modification of drawings as situations. For solving of those of the problems, it is emphasize on visual effect through introduction of 3-dimensional design from the initial phase. In case of national conditions, limited national land has caused increasing weight for construction of the roads through cities as the urban centered development. thereupon, citizens are increasing concern about the right of the light and the environmental effect, road designs and construction of the structures under agreement with local residents cause to make troubles. The analysis of 3-dimensional design is necessary as intermediation for decision making. In this study, Virtual reality techniques in 3-dimensional roads design are expected to visual effect on the publishing Internet Web, find problems in first phase and make decision between users and people having civil appeal.

• The Journal of Engineering Geology
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• v.30 no.1
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• pp.85-101
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• 2020

The estimation of strength parameters is very important for the stability analysis of rock slopes. Various methods for the determination of strength parameters were suggested by various researchers. The number of methods used for the estimation of strength parameters in the stability analysis of rock slopes were investigated based on literature reviews. The frequency of the method determining strength parameters were investigated with respect to failure types. The cohesion and friction angles of the rock and discontinuities are presented with RMR values. The cohesion shows wider range of values relative to those of friction angles according to current studies. Even though RMR does not show any correlation with cohesion values, RMR and the friction angle of the rock clearly shows a positive relationship. Proper methods should be utilized for the determination of strength parameters with consideration for failure types and be proved through literature reviews. The credibility of determining strength parameters is expected to improve if strength parameters data are accumulated from the back analysis performed for failed local rock slopes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.164-181
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• 2023

In a low speed limit environment, the speed limit tolerance of automated traffic enforcement devices is very high, which is one of the main factors for the low compliance rate. Therefore, in this study, we aimed to the improve the speed limit tolerance and to present a new standard. The effects of the operator and user errors that can cause speeding by drivers were analyzed. Based on the results of the analysis, an improvement of the tolerance was proposed by applying an error in the enforcement device and GPS speed. In addition, long-term expected safety effects such as the accident rate and severity were estimated from the operator's perspective when improving the tolerance. As a result of the estimation, the speed limit compliance rate, accident rate, and change rate of a number of severe accidents due to speed change, and pedestrian traffic accident mortality rate were all improved in all speed limit environments. The introduction of the proposed improvement is expected to improve road safety significantly.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.161-171
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• 2023

It is largely agreed that elderly drivers (over 64 years) are more likely to cause fatal crashes than other age groups. According to national road crash statistics 2021, the number of road fatalities per 10,000 drivers over 64 years old was 1.77, while that of drivers in their 30s was 0.55. This indicates a 2.67 times higher probability of causing crashes among the former than the latter. The current study estimates how rear-end crashes may be reduced by installing Automatic Emergency Braking Systems (AEBS), particularly for elderly drivers. We analyzed data from Samsung Fire & Marine Insurance. The results show that the Odds Ratio of rear-end crash occurrence between vehicles with AEBS and without AEBS is 0.75, implying there were lesser rear-end crashes in the vehicles installed with AEBS. The Odds Ratio of male drivers was determined to be 0.78, which was lesser than the 0.81 Odds Ratio obtained for female drivers. Elderly drivers who had installed AEBS in their vehicles showed an Odds Ratio of 0.76, implying crash reduction. In particular, the Odds Ratio of male elderly drivers was found to be the lowest at 0.49. We believe incentivizing by giving discounted insurance premiums to the elderly who drive vehicles installed with AEBS will help reduce rear-end crashes.