• International Journal of Highway Engineering
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• v.10 no.2
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• pp.135-143
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• 2008

According to the present highway design criteria, there are minimum standards which re ade from special design speeds. If some highways are satisfied the standards, it regards he highway as safety. In reality, however, most drivers drive a car at different speed compared with design speed. It is very dangerous for drivers especially at transition sections between curve and horizontal curve sections. Hence, this study calculated the rate of changing and horizontal acceleration at each section. Moreover, this study evaluated thesafety of design at curve transition sections and then calculated lateral acceleration and curve radii. This study found the minimum standards which are using as basic safety standards are not appropriate for measuring driver's safety.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.627-638
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• 2008

At present, there is a no rational MOE for evaluating hazard level at curve sections. Therefore, this study focus on developing the MOE and algorithm for hazard level at curve sections. The scopes of this study limited to rural two-way roads. Actual data used is accident, geometric features, safety facilities of the selected sites at curve sections. In order to develop MOE for hazard level at curve sections, accident contributing factors were classified by road geometry, visual guidance facility, speed and driver factor. A relationship between the four factors mentioned and accidents was conducted. And, the MOE for hazard level at curve sections was derived from the previous relationship analysis, and the algorithm for hazard level was developed. Finally, worksheets were suggested based on the MOE and algorithm for road designers. These developed MOE and algorithm can be used to reduce serious accident contributing factors when designing roads and also, these will be used to determine an order of priority when reconstructing roads.

• 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.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.582-590
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• 2015

Road type classification and K-factors are important role when design of number of lane. In this study not only classifies road type and estimating of K-factor but also economic evaluation tries for feasibility verification. Road type analysis results, time of day traffic volume variation, weekend-factor and vacation-factor are large in recreation roads. Weekday traffic volume and weekend traffic volume are similar patterns in provincial roads. AADT is high and time of day traffic volume variation is small in urban roads. In this study compares with economic analysis that designing of number of lane between KHCM's K-factor and this study K-factor. Economic analysis results, designed roads by this study's K-factor reduce cost about 4,708 hundred million won. So this study's K-factor is economical on provincial 4 lane roads.

• 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 the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.23-29
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• 2008

This research proposes two sub-models and one integrated model for the classification of safety in curve section of road, where the fatal-rate is relatively higher in accidents. The first sub-model calculates the accident-rate by safety-index that is based on the road geometries. The second decides the safety of curve section by the speed difference between before and in the curve. Finally, the integrated model of two sub-modules can classify the safety of curve section of road.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.663-673
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• 2009

Driver's perceived curve radius is different from actual curve radius at curve sections. This is called visual distortion. It has effect on operation speed according to driver's perception and finally bad effect on safety at curve sections. At present, however, there is no research on quantitatively analysis of visual distortion and no criteria for curve section design considering the visual distortion. Therefore, this study focus on finding degree of visual distortion and suggesting design criteria by visual distortion analysis. The process of this study is as below; First, a calculaiton model of perceived curve radius was developed by survey using computer simulation. In this model, a dependent variable is perceived curve radius and an independent variable is geometric factors. Second, degree of visual distortion was calculated from ratio of perceived curve radius to actual curve radius. Finally, design criteria were suggested through influencing factor analysis of visual distortion at curve sections.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.207-215
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• 2009

Generally, traffic accidents can be influenced by variables driving conditions including geometric, roadside design, and traffic conditions. Under the circumstance, homogeneous roadway segments were firstly identified using typical geometric variables obtained from field data collections in this study. These field data collections were conducted at highways located in several areas having various regional conditions for examples, outside metropolitan city; level and rolling rural areas. Due to many zero cells in crash database, a Zero Inflated Poisson model was used to develop crash prediction model to overestimated results in this study. It was found that EXPO, radius, grade, guardrail, mountainous terrain, crosswalk and bus-stop have statistically significant influence on vehicle to vehicle crashes at rural multi-lane roadway segments.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.141-146
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• 1999

본 연구는 평면곡선부의 차량속도변화와 교통사고에 대한 영향을 분석하기 위해 수행되었으며, 이를 위해 곡선반경별로 진입부 직선도로 - 곡선부 - 이탈부 직선도로로 구분하여 각 주행속도를 산정하였다. 본 연구에서는 선행차량에 의해 영향을 받지 않는 속도를 이용하여 평면곡선부 기하구조의 영향을 분석하였다. 이러한 곡선부의 주행 속도를 분석한 결과, 곡선반경별 최저속도와 그 속도가 나타나는 위치를 분석하였고, 해당 도로구간의 교통사고자료를 분석하여 평면곡선부의 차량주행속도변화와 교통사고 발생간의 관계를 규명하였다. 연구 결과는 다음과 같다. 첫째, 운전자들은 곡선시작지점에 도착하기 전에 충분히 속도를 줄이고, 곡선부에서 가장 낮은 속도가 나타나는 위치는 곡선시점의 후방에서 나타나고 이는 운전자의 시거에 의한 영향이다. 둘째, 곡선부에서의 속도변화폭이 클수록 사고위험성은 크고 실제 교통사고의 발생건수는 높다. 본 연구의 결과에 의해 도로 주행의 안전성을 고려한 평가지표를 개발할 수 있으며, 이에 의한 일관성 있는 도로설계를 유도할 수 있다.

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.69-82
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• 2004

Urbanization of Korea reaches up to 90% in the year 2003. What that means is that 90% of population live in the city areas. This phenomenon emphasizes importances of urban streets where people feel accessibility and level of environmental amenity, enjoy recreational activity, and live for a life. However, the current Korean manual for designing road is not enough to accomodate various activities of urban streets since its target is basically rural roads. This study proposes the necessity of a new design manual of urban streets via analyzing the practices of the development countries, and aims to recommend what should be prepared and how those are defined for developing a design manual of urban streets in Korea. It is inevitable that the design manual of urban streets be based on the flexibility and diversity. The manual should be made through consensus among the related stakeholders such as designers, residents and officials. And it also should reflect the characteristics of each city. It is somehow true that without the manual, designing of urban streets can be done although it is not fully acceptable. This does not mean that the necessity of the manual can be ignored. Rather, we should remember that the related stakeholders may not want to reveal what are hidden in developing the design manual of urban streets. What are hidden is that developing the design manual of urban streets is difficult problem to solve. It is a wish that this study triggers the on-going research and interests on developing the design manual of urban streets.