• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.95-101
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• 2016

Vehicular communications is system which can be applied for transmission of various safety messages or Intelligent Transportation Systems(ITS) applications by combining vehicle/road technology with Information and Communication Technology(ICT). In recent years, a variety of ITS services are available such as driving information, road conditions, V2X messages as well as navigation and traffic jams notification. In general, vehicular communications can be used for vehicle-to-vehicle and vehicle-to-infrastructure communication by adopting IEEE802.11p/1609 standard which is commonly known as wireless access in vehicular environments. In this paper, WAVE communication standard based on the IEEE802.11p is explained and signal characteristics in WAVE communication is introduced. Also, The H/W and S/W characteristics in Road Side Station and On Board Equipment for the Vehicle to Everything communication are analyzed. Received Signal Strength which is power of receiving signal of communication equipment is measured in test road to estimate the real WAVE communication's performance. It is shown that the implemented WAVE communication technology is satisfactory to provide ITS services.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.121-131
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• 2006

Considering characteristics of drivers and vehicles with proper and reliable ways in highway design Procedures can ensure high level of highway safety. However, it is almost impossible to take into account all factors of drivers and vehicles influencing on the highway safety because of their uncertain and random nature. To detour the dead-end, the nature are usually assumed as simple homogeneous and deterministic one. Although the restricted assumption makes the system simple, it can produce serious problems due to lack of considering variability in the system. This paper develops a reliability-based method for determining stopping sight distance(SSD) and intersection sight distance (ISD), which are crucial elements in highway alignment design. In the study, Hasofer-Lind method is adopted. which is a well-known first-order second moment reliability method (AFOSM) The results in this study show that if mean, variance, and distribution of a particular driver-vehicle parameter are known, more reliable sight distances can be applied in highway design procedures because we can reflect uncertainties and randomness. Thus, the Probabilistic method could be adopted in designing the sight distance(s) with the desired reliability level.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.155-166
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• 2002

Since 1990s. there has been an increasing number of traffic accidents at intersection. which requires more urgent measures to insure safety on intersection. This study set out to analyze the road conditions, traffic conditions and traffic operation conditions on signalized intersection. to identify the elements that would impose obstructions in safety, and to develop a traffic accident prediction model to evaluate the safety of an intersection using the cop relation between the elements and an accident. In addition, the focus was made on suggesting appropriate traffic safety policies by dealing with the danger elements in advance and on enhancing the safety on the intersection in developing a traffic accident prediction model fir a signalized intersection. The data for the study was collected at an intersection located in Wonju city from January to December 2001. It consisted of the number of accidents, the road conditions, the traffic conditions, and the traffic operation conditions at the intersection. The collected data was first statistically analyzed and then the results identified the elements that had close correlations with accidents. They included the area pattern, the use of land, the bus stopping activities, the parking and stopping activities on the road, the total volume, the turning volume, the number of lanes, the width of the road, the intersection area, the cycle, the sight distance, and the turning radius. These elements were used in the second correlation analysis. The significant level was 95% or higher in all of them. There were few correlations between independent variables. The variables that affected the accident rate were the number of lanes, the turning radius, the sight distance and the cycle, which were used to develop a traffic accident prediction model formula considering their distribution. The model formula was compared with a general linear regression model in accuracy. In addition, the statistics of domestic accidents were investigated to analyze the distribution of the accidents and to classify intersections according to the risk level. Finally, the results were applied to the Spearman-rank correlation coefficient to see if the model was appropriate. As a result, the coefficient of determination was highly significant with the value of 0.985 and the ranks among the intersections according to the risk level were appropriate too. The actual number of accidents and the predicted ones were compared in terms of the risk level and they were about the same in the risk level for 80% of the intersections.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.277-285
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• 1997

본 연구에서는 운전 중에 빈번히 나타나는 부작업을 모의 운전 실험하에서 선정하여 그때의 운전 수행 도와 운전자의 심리적 작업부하에미치는 영향에 대해 연구하였다. 운전의 수행도는 브레이크 작동시의 시간의 적절성을 사용하였으며, 이를 측정하기 위해도로교통안전협회에 설치되어있는 운전기능검사기기를 사용하였다. 또한 운전자의 심리적 작업부하를 측정하기 위해 심리적 작업부하 측정 방법의 하나인 NASA- TLX를 사용하였다. 다양한 운전 상황을 설정하기 위해도로의 형태를 골목길과 일반도로로 나누었으며, 부작업의 종류는 전화 걸기, 라디오 조작, 대화로 선정하였다. 실험에는 17명의 피실험자가 참가하였고 결과에 대한 통계분석(SAS)이 이루어졌다. 본 연구 결과, 운전시 전화 걸기와 라디오 조작의 경우가 다른 부작업에 비해 운전 수행도를 통계적으로 유의한 정도 저하시키는 것이 조사되었다. 부작업에따라서 3 . approx. 22%의 수행도의 저하가 나타났으며, 42 .approx. 59%의 심리적 작업부하의 증가가 나타났다. 본 연구에서는 부작업이 정도의 차이는 있으나 수행도의 감소와 심리적 작업부하의 증가를 유발시키는 것이 정량적으로 입증되었다. 차후 보다 실제상황에 가가운 모의 실험과 다양한 수행도 측정지수를 사용한 연구 를 통해 운전시 부작업이 사고에 미치는 영향이 검증될 것으로 기대된다.

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.160-168
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• 2017

In the past 10 years, the accidents caused by drowsy driving have occupied about 23% of all traffic accidents in Korea expressway network and this rate is the highest one among all accident causes. Unlike other types of accidents caused by speeding and distraction to the road, the accidents by drowsy driving should be managed differently because the drowsiness might not be controlled by human's will. To reduce the number of accidents caused by drowsy driving, researchers previously focused on the spot based analysis. However, what we actually need is a segment (link) and occurring time based analysis, rather than spot based analysis. Hence, this research performs initial effort by adapting link concept in terms of drowsy driving on highway. First of all, we analyze the accidents caused by drowsy in historical accident data along with their road environments. Then, links associate with driving time are analyzed using digital tachograph (DTG) data. To carry this out, negative binomial regression models, which are broadly used in the field, including highway safety manual, are used to define the relationship between the number of traffic accidents on expressway and drivers' behavior derived from DTG. From the results, empirical Bayes (EB) and potential for safety improvement (PSI) analysis are performed for potential risk segments of accident caused by drowsy driving on the future. As the result of traffic accidents caused by drowsy driving, the number of the traffic accidents increases with increase in annual average daily traffic (AADT), the proportion of trucks, the amount of DTG data, the average proportion of speeding over 20km/h, the average proportion of deceleration, and the average proportion of sudden lane-changing.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.156-168
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• 2017

Personal mobility (PM) can increase the mobility of individual, so that the elderly can be set as the target group for using PM because of relatively low walking ability to normal. In this study, we design PM device for elderly that can be used safely in the walking environment such as sidewalk. There are various obstacles in the walking environment, so the device must have mechanical performance to overcome all of them. In this study, we survey the status and level of obstacle factors in walking environment to determine the dynamic performance of the PM device for elderly. We check up several guidelines about walking facilities to define obstacle points for the device, establish field survey methodologies, and conduct field survey for some specific road sections. Based on the survey results, we confirm the possible problems that could arise when the dynamic performance of the device is selected based on the facility-related criteria. We also define the performance requirements for the device based on the requirements for electric wheelchair.

• Journal of Korean Society of societal Security
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• v.1 no.3
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• pp.59-67
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• 2008

The most influential facility causing traffic disaster on the urban road is intersection. Accordingly, this study elected a region for case study from seabang three-way junction, partial section of Dongmoon Ro in Kwang-Ju city, to the intersection of Mudeung Library Entrance. It is believed that the signal progression is very effective on the basis of short interval of intersection and massive traffic volume. The signal progression was simulated by using TRANSYT-7F model. The following is summary of the simulation: According to the change of cycle length, P.I. delay and fuel consumption showed the tendency of being increased in case that cycle length becomes long or short, centering around the best cycle length. In the event of progressing the cycle length, the average speed per vehicle is increased by 11.39Km per hour and P.I value is improved by 40.65% so that it resulted in 42.86% improvement in the total travel time. Moreover, the fuel consumption in line with the progression practice produced fuel saving of 31.04%.

• Journal of the Korean Geotechnical Society
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• v.38 no.1
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• pp.5-15
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• 2022

Due to the Pohang earthquakes in 2017, concerns are increasing that Korea is no longer safe from liquefaction, and needs the research to take proper measures for liquefaction. Liquefaction is defined as the loss of shear strength of the ground. In order to solve this problem, many studies, such as composing a liquefaction hazard map using Liquefaction Potential Index (LPI), have been conducted. However, domestic researches on the comparative analysis of liquefaction prediction results are not sufficient. Therefore, in this study, liquefaction hazard maps were composed using the standard penetration test results, shear wave velocity values, and cone penetration test results. After that, the precision was determined by comparing the calculated LPI using the geotechnical information and predicted LPI via spatial interpolation target. Based on the analysis results, the predicted LPI value using geotechnical information is more precise than using calculated LPI value.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.94-101
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• 2021

According to the Facility Management System (FMS) operated by the Korea Authority of Land & Infrastructure Safety, it is expected that the number of aging facilities that have been in use for more than 30 years will increase rapidly to 13.9% in 2019 and 34.5% in 2929, and end up with a social problem. In addition, with the revision of "Common Application of Seismic Design Criteria" by the Ministry of Public Administration and Security in 2017, it is mandatory to re-evaluate all existing road facilities and if necessary seismic reinforcement should be done to minimize the magnitude of earthquake damage and perform normal road functions. The seismic performance management-decision support technology currently used in seismic performance management practice in Korea only determines the earthquake-resistance reinforcement priority based on the qualitative index value for the seismic performance of individual facilities. However with this practice, normal traffic functions cannot be guaranteed. A new seismic performance management decision support technology that can provide various judgment data required for decision making is needed to overcome these shortcomings and better perform seismic performance management from a road network perspective.

• Journal of Auto-vehicle Safety Association
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• v.8 no.4
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• pp.12-17
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• 2016

NHTSA (National Highway Traffic Safety Administration) has offered consumers the vehicle safety information on their car since 1978. NHTSA believes that they contribute auto makers to develop safer vehicle for customers, which will result in even lower numbers of deaths and injuries resulting from motor vehicle crashes. NHTSA has been studied why people are still dying in frontal test despite of the use of many restraints system and they understand that current test does not reflect real world crash data such as oblique and corner impact test. As a result, NHTSA announced that a new test method will be introduced to use of enhanced biofidelic dummy and new crash avoidance technology evaluation from 2019. New and refined injury criteria will be applied to Head / Neck / Chest / Lower Leg. BrIC(Brain Injury Criterion)value in NHTSA test results using THOR dummy from 2014 to 2015 was average 0.91 and 1.24 in driver and passenger dummies. IIHS 64kph SOF test is the most likely to new frontal oblique test in an aspect of offset impact which is being studied by NHTSA. In this paper, we focused on head injury, especially brain injury - BrIC and conducted IIHS 64kph SOF (Small Offset Front) test with Hybrid III dummy to evaluate the injury for BrIC. Based on the test results, these data can be predicted BrIC level and US NCAP rating with current vehicle.