• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.129-148
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• 2006

The objective of this thesis is to develop a capacity analysis and to develop a methodology to evaluate Level of Service over the entire freeway sections by single MOE (Measure of Effectiveness) This study set forth from a following viewpoint. to analyze entire freeway sections as freeway facility system, it is important to identify the exact point where congestion would occur and the extent of the congestion. Therefore, in this thesis, congestion mechanism on freeways was figured out and congestion analysis methodology was developed. Thereby maximum possible throughput rate and maximum throughput rate in bottleneck sections were calculated and a congestion analysis was carried out. The difference between the new method and existing Procedures is that maximum possible throughput rate and maximum throughput rate. that can be considered as capacities of un-congested and congested flow in the bottleneck section, are variable capacities dependent on demand flow.

• 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.34 no.3
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• pp.278-290
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• 2016

Maximum traffic flow rate is an important performance measure of operational status in transport networks, and has been considered as a key parameter for transportation operation since a bottleneck in congestion decreases maximum traffic flow rate. Although previous studies for traffic flow analysis have been widely conducted, a detection method for changes in dynamic traffic flow has been still veiled. This paper explores the dynamic traffic flow detection that can be utilized for various traffic operational strategies. Turning point analysis (TPA), as a statistical method, is applied to detect the changes in traffic flow rate. In TPA, Bayesian approach is employed and vehicle arrival is assumed to follow Poisson distribution. To examine the performance of the TPA method, traffic flow data from Jayuro urban expressway were obtained and applied. We propose a novel methodology to detect turning points of dynamic traffic flow in real time using TPA. The results showed that the turning points identified in real-time detected the changes in traffic flow rate. We expect that the proposed methodology has wide application in traffic operation systems such as ramp-metering and variable lane control.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.195-205
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• 2001

The objective of the paper is to analyze the traffic characteristics for freeway merging area. Freeway merging area is different from basic section due to ramp vehicles. Therefore, to understand the traffic characteristics of (leeway merging area, this study focused on two factors including critical time headway required in merging maneuver and maximum possible merging volume. In this paper, new model that adopts critical time headway instead of critical time gap in calculating the maximum possible merging volume based on probability function was developed In previous studies, for calculating the maximum possible merging volume, it was considered that merging vehicles could merge freely if a given time gap was greater than the critical time gap. Also, the critical time gap was used as the same value in all traffic flow conditions. But, a time gap required in merging maneuver could be changed, even to the same driver, because difference of relative speed varies in different traffic flow conditions. So, in some cases, the critical time gap could be insufficient value in merging maneuver. Therefore, in this study. a calculating procedure for critical time headway in all traffic flow conditions was presented. Also, the maximum possible merging volume and capacity for freeway merging area were calculated by using the previously found critical time headway.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.17-23
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• 2011

It has been presumed that the amount of vehicle's $CO_2$ emission would highly related to vehicle's cruising speeds on highways. In this study, it was tested if vehicle's $CO_2$ emissions would relate to the types of highways and the level of congestion. The results showed that the amount of $CO_2$ emission changes depending on (1) the vehicles' cruising speeds (b) congestion levels, and (c) the types of intersections. It was found that the vehicle acceleration and deceleration methods increases the amount of $CO_2$ emission up to 12%. It was also found that it changed up to 30% and 40% depending on the level of congestion and the types of intersections, respectively. The findings imply that the amount of $CO_2$ emission from vehicles should be improved when vehicles' cruising speeds are well managed through congestion management.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.85-97
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• 2001

In this study, the purpose behind this research is to propose index to be used for classification of functional the urban streets and to select the feasible length of special management link by the index. This special management link help decision makers found a transportation policy. In order to perform functional classification, index such as average traveled distance, link VKT and VKT per length-lane are use at the study. Average traveled distance index is average traveled distance divided by length of Path k and VKT per length-lane is trip volume characteristic considering lanes and length of Path k. Special management links on which major part of the vehicle are selected with using Path-VKT which represents how many long-distance touring vehicles are on the arterial road. The selection of special management links are performed with network composed of 14 paths (arterial roads) in seoul The total distance of special management links resulted from the above analysis is 141km(35.0% of the whole paths length) and total VKT of the special management links is 4,152,475 VKT(45.2% of the whole paths VKT)

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.103-111
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• 2003

This study proposes methodology deterimining a basic pedestrian crossing capacity that plays a critical role in the installation of pedestrian signal at the crosswalks. The methodology is based on the pattern of vehicle arrived at the crosswalks. Erlang distribuion is used as headway distribution that can cover the various levels of flow rate. Models using Erlang distribution are represented by Erlang parameter (K) of 1, 2, or 3 at 2-, 4-, or 6-lane roadway in both directions. In addition, this study considered the only type of road with a pedestrian refuge area in the median that is used to wait for the allowable gap provided by the flow of another direction. As a result, the pedestrian capacity decreases as flow rate increases and Erlang parameter increases for the road with the pedestrian refuge. This study develops the models to determine the pedestrian capacity under a variety of flow rates and the outcomes of this study could be used as the criteria for the determination of the installation of pedestrian signal or for the provision of pedestrian refuge in the median of road.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.59-65
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• 2003

For safe passing the waterway crossing bridge without collision with bridge-piers under poor visibility circumstances, it is very important that the pier should be detected definitely as earlier as possible by radar, In this study, the required length of Projecting part of the bridge pier for definite radar recognition was obtained by theoretical and experimental analyses. By presenting the required values depending on the maximum vessel size and passing condition, it is expected possible to design the bridge pier protecting system appropriately suitable to traffic environment of the waterway.