• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.54-62
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• 2010

The scientific analysis of car-pedestrian accidents is not an easy task because of the characteristic of the accidents itself. Since the analysis involved human being, there were few experimental data that could be used for the analysis. The coefficient of friction of human body was the one of crucial data for accident analysis, but no field experiment report was available for various roadway conditions. This study intends to measure the coefficient of friction of human body through field studies. Results showed that the coefficient of friction of human body for dry asphalt pavement conditions was 0.59~0.62, and for dry concrete pavement conditions was 0.59~0.61. In addition, the coefficients for wet asphalt pavement and for wet concrete pavement conditions were 0.56~0.59 and 0.51~0.54 respectively, indicating 5.0% and 8.3% reduction compared to the dry conditions. The deduced coefficients were validated using the simulation program. It has been confirmed that the experiment values were close to the simulation results.

• Journal of the Korean Society of Safety
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• v.26 no.4
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• pp.127-134
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• 2011

A traffic accident which happens in Expressway during dense fog is more likely to cause the sequential accidents and high death rate. So, the preventive measures shall be taken at dangerous areas to enhance the efficiency of roads and minimize the accidents and the resultant damages. So, it is necessary to find out the characteristics of freeway zone which has high risk of fog occurrence and to establish the comprehensive safety strategy on installation and operation of the safety equipment. In this study, I developed a fog forecasting model by using the freeway fog data. This model can be used as the fog forecasting model in dealing with fog problems when new road is planned. The model was developed by using a statistical analysis technique or the regression analysis, focusing on the variables such as geographical features and regional conditions, distances to water sources and the area of water source. I have segmented the models by classifying the area into inland area and coastal area. The distance to water source and area of the water source located around the freeway were found to be main factors causing fog.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.75-82
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• 2016

PURPOSES : This study was initiated to estimate the benefits from the campaign to prevent drowsy driving crashes on expressways. The study was conducted by the Korea Expressway Corporation using a contingent valuation method. METHODS : First, a questionnaire was designed for a preliminary survey. From the survey's results, the initial willingness to pay for the campaign was determined by averaging different amounts of payments chosen under virtual scenarios in the survey. The willingness to pay data was used to find a first bid price for the open-ended method used for the second survey. After that, a primary questionnaire was designed and conducted using a single dichotomous choice question (SDBCQ). Drivers at expressway resting areas were asked their willingness to pay for the campaign. Based on statistical analysis using data collected from the second survey, the mean willingness to pay was estimated using a probability utility function. Finally, the benefit from the campaign was calculated using the estimated willingness to pay and accident data on expressways. CONCLUSIONS : Based on the result from the contingent valuation method, the benefit from the campaign to prevent drowsy driving crashes was estimated to be 170.6 won per expressway trip. The benefit is to be paid as an additional toll. In addition, the traffic crash cost estimate is about 2,209,680,000 won less than the cost during the same period in 2014.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.3
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• pp.24-32
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• 2007

Variable message sign (VMS), which is used for providing real-time information on traffic conditions and accident occurrences, is one of the important components of intelligent transportation systems. It is essential that the scheme of VMS message phase and duration should be designed with the consideration of drivers' message reading time that will be depended on various causal factors, such as the amount of VMS messages, drivers' travel speed, and geometric conditions. However, there have been not much efforts to explore the relationships between the drivers' message reading time and the above causal factors. Driving simulator experiments were conducted to obtain drivers' message reading time with respect to the amount of VMS messages, drivers' travel speed, and different geometric conditions. Regression modeling techniques were applied to develop an estimation model for drivers' message reading time. Probabilistic outcomes of the proposed model would be greatly utilized to design proper VMS message phase and duration.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2192-2204
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• 2011

Recently, The government is actively transit road-oriented Traffic System to the eco-friendly and high-efficiency railroad-oriented transportation system for the sustainable green growth. The second plan of Nationwide Railway Network which has been officially announced rearrange to integration, multi-core, open architecture country by the railway network and integrate to the one mega city that rink an important city in one hour 30 minute. But the railroad industry is disadvantageous when it compares with the road industry on the ground that railroad industry peculiarities(a cost-benefit analysis, an environment value, etc) have not reflected in the (preliminary) feasibility study for SOC industry. The government establish Improved methodology of Rail Investment Rating System and improved preliminary feasibility study in railroad project by introduction many content(analysis periods, rate of discount, the benefits of shortening of transit hours, the estimation of traffic accident reduction benefits, investment cost of vehicle substitution and operation and maintenance cost of high speed rail) about the Improved methodology of Rail Investment Rating System. This study is intended to consideration the key content that was included in the Improved methodology of Rail Investment Rating System. In addition, the points to be considered for additional study have been reviewed in this study. We hope we will carry out make a reasonable and objective Rail Investment Rating System and to perform the railway industry of the virtuous cycle such improvement plans are reflected at a hereafter railroad section.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.50-59
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• 2015

This study aimed at suggesting Willingness To Pay (WTP) for introduction of the Traffic Accident emergency Call (TAC) system by using Contingent Valuation Method (CVM) which is a general valuation method. As the method, this study suggested a WTP estimation method of the TAC system with the double-bound dichotomous choice model. In previous studies, the data are processed differently according to the type of questions and analysis models used for the calculation of willingness to pay. Therefore, we re-organized the model by the cases using the truncated data sets, and showed the difference in WTPs. The dataset was developed by more than 500 questionnaire obtained from online and offline survey with the consideration of composition ratio by age group referring housing census in 2010 to mitigate regional bias of samples. At last, this study applied various statistical methods, survival analysis, multiple regression, and Tobit model for better interpretation of the questionnaires.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.71-71
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• 2018

Sea pollution accidents have been occurred due to the increase of marine ship traffic. Oil spill from the hull hole induced by tanker collision results in the huge sea pollution. Proper and prompt reaction on such oil spill disaster is needed to minimize the damage. Thru-hull emergency wood plug is typically used to manually close small holes, while it is required to develop some mechanical devices for closing large holes in the hull due to huge fluid pressure. Accurate estimation of oil discharge and velocity from such holes are important to develop proper device to control hull hole damage. High resolution CFD modeling investigation on the configurations of hull hole of 7.5 m initial depth and 30 cm diameter, which was observed in the oil spill accident of the Hebei Sprit off the west coast of Korea in 2007, has been carried out to compute the oil spill velocity distribution in terms of flow depth. Friction loss due to the viscous flow and the discharge coefficient of crude oil with specific gravity SG = 0.85 and viscosity of $4-12cP(mPa{\cdot}s)$ at the temperature of $20^{\circ}C-100^{\circ}C$ are presented in terms of Reynolds number based on the results of high-resolution CFD modeling.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.119-131
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• 2021

This study quantitatively derived the direct socio-economic effects of the Gyeongbu Expressway, which opened in 1970, and suggested a methodological approach for more reliable results. The scenario was set when the Gyeongbu Expressway was not constructed in 1970, the opening of the Gyeongbu Expressway was delayed by 10 years, and the toll road between Seoul and Daejeon, or between Seoul and Gangneung was opened instead of the Gyeongbu Expressway as suggested by the World Bank. In addition, direct benefits were estimated by calculating and comparing the current vehicle operating costs, travel time costs, traffic accident costs, and environmental pollution costs. As a result, it was estimated that about 351 trillion won in direct benefits occurred, and it can be seen that the promotion of the construction project of the Gyeongbu Expressway at that time had a huge impact on South Korea's social economy.

• 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.