• International Journal of Highway Engineering
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• v.18 no.6
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• pp.161-171
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• 2016

OBJECTIVES : Many roadway departure crashes on the freeway interchange are due to the running speed being greater than the design speed. This study aims to ensure a safe and pleasant driving experience for the driver by increasing the superelevation based on the running speed on the highway interchange ramp. METHODS : The mean running speed for each type of ramp is calculated on site survey more than 10 interchanges. Using the mean running speed, we calculated the superelevation and the side friction using the method given in "A Policy on Geometric Design of Highways and Street" (Pages 145-166, 2001). Then, we applied the modified method to the superelevation range. Finally, we ensured safety using the Degree of Safety that is proven by the centrifugal acceleration ratio as suggested by Joseph Craus (1978). RESULTS : The mean running speeds are 50 km/h and 65 km/h when the design speeds are 40 km/h and 50 km/h, respectively. After the application of the new method used in this study, the superelevation will be increased by 9.0% and 10.0% when the mean running speeds are 50 km/h and 65 km/h, respectively. CONCLUSIONS : A higher superelevation can give the driver a more comfortable and safe driving environment. However, the driver needs to be aware of snow and low-temperature conditions.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.91-101
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• 2003

This study modeled 4-lane highway in three-dimensional virtual reality in order to overcome difficulties of field experiment. and the research subject was placed in a driving simulator. We survey the driver's cognitive characteristics to the alignment changes in the three-dimensional virtual reality highway. Especially, maximizing the identity of driving movements and virtual scenery on the basis of the data obtained by dynamic analysis module. we minimized simulator sickness for the graphic module of driving simulator. And we carried out cognitive evaluation on the basis of adjective words extracted by dictionary and the opinion of specialist. In this study LISREL model was used to detect the causal relation between geometry and safety in cognitive side, and found that geometric change affects the safety of drivers by static and dynamic road safety model in three-dimensional combined alignments. As the result, for constructing safety road. we consider drivers' cognitive characteristics as human factors in road design, and we think that they are very important factors to improve road safety.

• Structural Engineering and Mechanics
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• v.57 no.5
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• pp.951-968
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• 2016

Long-span cross-strait bridges extending into deep-sea waters are exposed to complex marine environments. During the construction stage, the flexible freestanding bridge towers are more vulnerable to environmental loads imposed by wind and wave loads. This paper presents an experimental investigation on the dynamic responses of a 389-m-high freestanding bridge tower model in a test facility with a wind tunnel and a wave flume. An elastic bridge model with a geometric scale of 1:150 was designed based on Froude similarity and was tested under wind-only, wave-only and wind-wave combined conditions. The dynamic responses obtained from the tests indicate that large deformation under resonant sea states could be a structural challenge. The dominant role of the wind loads and the wave loads change according to the sea states. The joint wind and wave loads have complex effects on the dynamic responses of the structure, depending on the approaching direction angle and the fluid-induced vibration mechanisms of the waves and wind.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.135-141
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• 2013

PURPOSES : The lack of details of design guideline for zig-zag shaped section approaching central bus stop leads an traffic accident proneness. So, this study analysed the geometric elements of central bus stop area in terms of vehicle dynamics and suggested design alternatives. METHODS : The study analysed a dynamic behaviour of bus moving in and out of zig-zag shaped section using Auto-Turn under scenarios. Based upon dynamic analysis, the study found out the width of overtaking lane is the most influential factor for a safe moving at zig-zag alignment. RESULTS : The width of overtaking lane at design speed of 40, 50, and 60 km/h respectively was suggested given taper ratio of 1 to 10 required for Bus Rapid Transit (BRT), and the lane width is not wider than 4.0m which possibly makes two vehicles using the same lane. Also, the width of overtaking lane which mitigates the taper ratio was suggested with the same restriction about the maximum lane width. CONCLUSIONS : The results of the study can be used to prepare a design guideline on zig-zag shaped alignment of central bus exclusive lanes. The more stable moving is expected by applying the design alternatives suggested, therefore the lower rate of traffic crashes at the vicinity of central bus stops.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.151-160
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• 2009

The aim of this study is to propose economical driving speed index which those are geometric road status; assess the levels of which those cost-benefit of driving energy consumption and emission; are search road safety design and operational technology for driving simulator. For the objective, we analyzed the current status of driving energy consumption and driving scenarios by the road alignments, and reviewed driving and technical specifications by the geometric types of road according to the implementation, and extended completion. Throughout the result of this study, diverse related driving information provision service, efficiently navigation driving module is expected to be implemented in the national highway design system.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.69-77
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• 2008

This article proposes new method for estimating pedestrian quality of service(QOS) that is useful to changing pedestrian environment by examining pedestrian quality of service as well as developing new method that integrate qualitative variables into the estimating indicators for the pedestrian movement right. Based on survey questionnaire addressed to experts group, the obtained data for the indicators were analyzed through Analytic Hierarchy Process(AHP). The results show that pedestrian traffic flow(quantitative figure: 52%), sidewalk geometric(quantitative figure: 16%), sidewalk usage behavior(qualitative figure: 11%) in commercial and business zone pointed out the importance of quantitative indicators such as pedestrian traffic flow, and sidewalk geometric. In addition, the results also show that pedestrian traffic flow(quantitative figure: 30%), sidewalk geometric(quantitative figure : 22%), sidewalk usage behavior(qualitative figure: 20%) indicate the significance of qualitative indicators such as pedestrian's sidewalk usage.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.217-224
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• 2004

This paper proposed a new impact equation by analyzing the form of the proposal section 1 and section 2 proposed by Korea Highway Corporation, F-type, NJ-type and SS-type with HVOSM program Because the impact equation proposed by Ministry Construction ＆ Transportation(1992) considered an only impact velocity, the values of impact loads calculated by HVOSM program are 21.5∼44 times as large as those using equation of MCT. The values of HVOSM program are 1.4 times as large as those of Olson's model because Olson's equation consider impact vehicle, impact velocity and impact angle. But, it does not consider geometric characters, while HVOSM program considers characters. Considering the shapes of sections and the conditions of colliding, HVOSM program can calculate imuact load. As Multiple Regression Analysis is conducted with the calculated values, the R² values of the proposed equations are 0.984 in SB1∼SB3 and 0.958 in SB4∼SB6. After all, the equation proposed in this study have better results than Olson's equation.

• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.109-118
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• 1990

본 고는 도로선형 설계에 확율 및 경제요소를 반영시키는 방법과 그에 따른 효과를 파악하는데 목적을 두고 있다. 접근방법은 도로사용자 비용과 도로시공 및 유지관리 비용 등을 포함하는 총비용을 예상비용함수로 나타내어 이 비용함수를 최소화함으로써 최적 도로선형 설계방법을 찾는 것이다. 이와 더불어 본 고는 이 개념에 의한 최적 설계방법을 등반차선(Climbing lane)의 설계에 적용하였다. 즉, 오르막길의 경사 및 거리에 따른 등반차선의 최적 위치를 찾기 위해 우선 오르막길에서의 승용차와 트럭의 속도분포를 찾아내고 예상예비함수를 등식화하여 그 최적해를 구함으로써 등반차선의 최적 위치를 구하였다. 현재 등반차선의 설계과정(AASHTO, 1984)은 트럭 주행능력에 따른 가정과 트럭과 승용차의 최대 속도 차이를 임의로 선택하여 등반차선의 최적 위치를 찾고 있다. 따라서 본 고에서는 기존 등반차선 설계방법과 새로운 설계방법을 상호 비교하면서 새로운 방법의 타당성과 그에 따른 설계이점들을 증명하였다.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.117-132
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• 1994

Drivers select approach lane according to various traffic situations as well as their destination. This behavior affects the utilization of lanes and capacity analysis at urban signalized intersections. This paper presents the concept, behavior of lane utilization, and the lane utilization factors which included in the study. Preparation of Korean Highway Capacity Manual (1992). Lane utilization is affected by various traffic and geometric factors which are roadway side friction, median friction, and number of lanes, etc. and it converges to an equal utilization as the degree of saturation (V/C ratio) increase. Lane utilization factor is suggested by the degree of saturation and the number of lanes, and it is presented in this paper.

• Journal of KIBIM
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• v.3 no.3
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• pp.19-28
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• 2013

In Korea highway bridges, most piers are the type of one-column or multi-column ones. So, in this study, under an environment applying BIM so fast, to activate researches on two-column piers subjected to bidirectional seismic loading, a 3D parametric modeling method was selected when the model of two-column piers and one-column piers were formed. Also, interface module between input data in structural analysis and 3D model of RC pier was developed. The module can create the input data for non-linear structural analysis like material, geometric properties and additional coefficients.