• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.69-79
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• 1999

This study evaluated the chance of driver's Psychophysiological load of occipital lobe at freeway merging area and compared with basic driving section. Ten persons of 8 men and 2 women were investigated at 3 basic section and 3 merging areas on the Youngdong freeway. It is found that driver's load in acceleration lane before merging is 2.21 times higher than the basic driving section. Further, driver's load for merging was maintained fur 4 seconds after merging. Particularly, driver's highest loading point in merging behavior was found to be 80m from the gore area.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.109-116
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• 2012

This study is aiming to separate highway entrance ramps from impact zones which are considered the characteristics and real traffic situations in each lane and section. The results of this study can be applied to Lane Control System and control the traffic flow for highway more efficiently. Based on earlier studies which analyzed impact zones in entrance-ramp junction using the standard deviation of speed, this study divides more segmentalized impact zones according to the degree of turbulences. As a result of this study, about 800m of intervals, from 500m of upper flow (1,2,3 lane) to 300m of lower flow(2, 3 lane), shows similar traffic characteristics influenced by entrance ramp directly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.167-173
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• 2009

In general, an influenced area of merging section is defined as 500 m including 100 m upstream and 400 m downstream. However, from an observation of the actual traffic flow, it is found that merging effect influences more on downstream than upstream. In this study, an influenced area of merging section on freeway is analyzed by using turbulence which is defined as conflicts between vehicles. In order to overcome the limits of existing traffic flow detection system established with intervals of about 500 m, this study uses raw data collected from the detectors which are established in entrance ramps with similar road conditions. To divide data of each point into similar road conditions, the data of total 72 hours is sorted by Level of Service. An influenced area analyzed by standard deviation of speed is 700 m section of highway, including 300 m upstream and 400 m downstream, for both right and left ramps. It is the result including upstream 200 m more than previous studies.

• Journal of Korean Society of Transportation
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• v.15 no.1
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• pp.105-127
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• 1997

합류구간은 다양한 교통특성을 분석하는데 어려움으로 인하여 그 동안 체계적인 연구가 거의 수행되지 않았다. 본 연구는 고속도로 합류부의 교통특성 측면에서 연결로 교 통량의 영향을 분석하고 평가하는 것을 목적으로 한다. 선형회귀 모형식이 연결로 교통량의 영향을 평가하기 위하여 개발되었고 기존의 모형식들과 비교되었다. 이러한 모형식은 본선 교통량과 연결로 교통량과의 상호 관계로 규명하는데 사용되었고 합류교통량에 대하여 연결 로 교통량이 본선교통량보다 더 많은 영향을 나타내는 것으로 분석되었다. 또한 교통와해 시점의 교통량 자료를 추정하기 위해 사용한 교통량 누적 감산법(the Background Flow Count Reduction Method)은 직접적으로 자료를 수집하기 어려운 지점의 자료를 추정하는 데 있어 유용한 방법임을 알 수 있었다. 향후에는 연결로 교통량의 영향을 고려한 합류부 운영방안이 필요하고 이를 통한 효율적인 합류부 운영이 이루어질 수 있을 것이다.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.99-109
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• 2004

Most traffic congestion on a freeway occurs in the merge area, where conflicts between mainline traffic and on-ramp traffic are frequently generated. So far, research on the merge area has mainly dealt with free flow traffic and research on the congested traffic at the merge area is rare. This study investigates the relationships between mainline traffic and on-ramp traffic at three different segments of the merge area. For this purpose, new indicators based on such traffic variables as flow, speed, and density are used. The results show that a negative relationship exists between mainline and on-ramp flow. It is also found that the speed and the density of the right two lanes in the mainline traffic are significantly affected by the on-ramp flow. Based on the correlation analysis of the indicators, it is confirmed that the ramp influence area is the right two lanes of the freeway mainline. The revealed relationships between mainline and on-ramp traffic may help to analyze the capacity of the downstream freeway segment of the merging area in congested traffic. The findings of this studyalso provide a basis to develop a model that estimates the merge traffic volume in congested traffic, which is neither theoretically nor empirically sound in most other traffic flow models developed so far.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.115-128
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• 2006

The analytic methodology of a merging area in KHCM(2004) supposes that congestion nay occur when traffic demand is more than capacity However, in many cases, congestion on merging area occurs when summation of traffic demand of main line and ramp is less than capacity, and in present methodology analysis of how main line and ramp flow effect on congestion occurrence is difficult. In this study, the model that is able to estimate traffic flow condition on merging area in accordance with the combination of main line and ramp demand flow is developed. Main characteristic of the model is estimation of maximum possible throughput rate and maximum throughput rate according to the combination of main line and ramp demand flow. Through the estimation of maximum possible throughput rate and maximum throughput rate. it was Possible to predict whether congestion would occur or not and how much maximum throughput rate and congestion would be on merging area. On one hand, in present LOS evaluation methodology on merging area, congestion state is determined as un-congested flow if demand flow is less than capacity. Therefore, to establish more reasonable In evaluation method, new criterion of LOS evaluation on merging area was searched based on the model of this study.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.115-128
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• 2002

Traffic engineers have developed and implemented various microscopic simulation models to verify the traffic performance and to prevent the expected problems. The existing microscopic simulation models categorize drivers into several types to reflect various drivers' driving patterns but miss the dynamics of drivers' behavior changed based upon the traffic conditions. It was found from the field data collected from two different merging sections on an urban freeway in Seoul, Korea, that the drivers' critical gap distributions are changed based on (1) the traffic density on the adjacent lane to the acceleration lane and (2) the opportunities left to merge in terms of distance to the end of acceleration lane. It was also found from the study that the drivers' critical gap distributions follow the Normal distribution. and its mean and variance change while a vehicle progresses on an acceleration lane. This paper proposes a new gap-acceptance model developed based on a set of drivers' critical gap distributions from each segment on the acceleration lanes. Through the comparison study between the field data and the results from the simulation utilizing the proposed model, it was verified that (1) the distribution of merging points on an acceleration lane to the adjacent main lane at different density levels, (2) the size of the gap accepted for merging and (3) the speed difference between the merging vehicle and the trailing vehicle at the time of merging are statistically identical to the field data at 95% confidence level.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.73-81
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• 2007

The purpose of this paper is to perform a basic study on the interaction between lanes, which can be achieved through analyzing traffic breakdown at the microscopic level. Using aerial photographic data for the microscopic analysis, this study analyzed the characteristics of traffic flow at a merging area. This research produced aggregated traffic data such as flows, speeds, and densities in 30 second intervals by lane for the macroscopic analysis and individual headway data by lane for the microscopic analysis. The paper contains an analysis of lane characteristics through flows, speeds, densities, and headway variations and also investigates the influence of ramp flows on mainline flows with space-time diagrams. Firstly, the merging area in this study is divided into three sections: before-merging, during-merging, and after-merging. The transition process was analyzed at each lane. Secondly, the breakdown was observed in detail with data divided in 50-foot units. The breakdown was checked through the relationships between ramp and freeway mainline flows, various techniques were proposed to analyze the breakdown, and the formation of breakdown was introduced as three stages in this study. In the near future, the findings of this study could contribute to determining the dynamic capacity on freeways by easily understanding changeable traffic breakdown patterns over time and space.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.221-227
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• 2008

This study identifies the relationship between traffic data quality obtained from loop detectors and their location. Traffic data basically shows traffic flow conditions and thus, these information can be used as inputs for various transportation management strategies. Out study presents how to determine optimal downstream detector location on merging area in order to enhance the effects of ramp metering strategies. Microscopic simulation model, PARAMICS, is used as the main analytical tool. Assuming that detector location relies heavily on traffic flow characteristics in each roadway segment, we perform statistical analysis to identify homogeneous traffic conditions on merging area.

• Journal of Korean Society of Transportation
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• v.16 no.2
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• pp.53-65
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• 1998

합류구간에 설치된 차량검지기에서 수집된 조사자료들을 이용하여 본 연구는 교통와해 발생원인과 용량감소 문제를 분석하였다. 본 연구에서는 거시적 및 미시적인 방법을 가지고 수행하였으며 거시적인 방법으로는 연결로 교통량의 상대적 비중차이를 분석하였고 미시적으로는 본선에 진입하는 차량들의 패턴을 분석하였다. 거시적인 측면에서 합류부의 교통와해는 같은 합류교통량에 대한 연결로교통량의 비중 차이레 의해 발생된다. 즉, 연결로교통량 비중이 높아질수록 교통와해 발생확률은 증가할 것이다. 또한 미시적인 측면에서는 연결로 교통량이 같을 때 본선에 진입하는 차량군의 크기 및 발생회수, 표준편차가 높아진다고 할 수 있다. 따라서 교통와해의 주요한 원인은 연결로교통량의 영향에 기인한다고 할 수 있고 이러한 영향을 감소시키기 위하여 램프미터링과 같은 고속도로 교통통제 기법이 요구된다.