• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.55-61
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• 2019

To improve bus service quality and passengers' safety at bus stops, it is necessary to analyze the relationship between bus stopping behaviors and bus stop conditions. Thus, this study investigated the proper stopping rate at 31 bus stops on Central Boulevard in Busan metropolitan city and analyzed the relationship between the proper stopping rate and bus stop operating conditions such as the length of berth, the distance from the front line of berth to bus shelter and so on. The analysis results show that the proper stopping rate is 45.82 % and the rates are closely related to each bus stop operating condition. Therefore, it is highly recommended that the front line of berth should be located parallel to bus shelter for improving the safety of bus passengers. In addition, it is suggested that the length of berth should be longer than 15m and the pavement marking of berth be redesigned with dash lines to take account of buses' entering and leaving the berth.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.12-20
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• 2015

The subway is one of the representative urban public transportation systems. Since its being opened in 1974, the Seoul Subway has been continually extended, and new lines are being added in the metropolitan and outskirt areas, even at present. As a result, the numbers of transfer stations and transfer sections have been significantly increased, making the usage of the subway system more and more complicated. In the transfer stations with big floating population and overlapped flows of traffic in the subway, passengers want their movements to be more precise and faster, without taking the wrong trains by mistake. Therefore, the visual information system for the subway inside the stations is extremely important. At the same time, the visual information system is required to be easy to understand and use, even if the passengers do not have previous experience of using the subway. In this research we studied the problems existing in the visual information system which is currently working in the subway system, and suggest the direction of the improvement of the subway service based on our studies. This research was mainly performed at Sindorim Station, one of the busiest stations in Seoul Subway with huge floating population and complex transfer sections. The purpose of this research is the investigation of behavioral and recognitive characteristics of passengers in the transfer sections through preceding research and qualitative analysis, to draw the direction for future improvement of the current system and suggest the improved experience of using the subway system.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.139-149
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• 2004

As the expansion of road capacity has become impractical in many urban areas, congestion pricing has been widely considered as an effective method to reduce urban traffic congestion in recent years. The principal reason is that the congestion pricing may lead the user equilibrium (UE) flow pattern to system optimum (SO) pattern in road network. In the context of network equilibrium, the link tolls according to the marginal cost pricing principle can user an UE flow to a SO pattern. Thus, the pricing method offers an efficient tool for moving toward system optimal traffic conditions on the network. This paper proposes a continuous network design program (CNDP) in network equilibrium condition, in order to find optimal congestion toll for maximizing net economic benefit (NEB). The model could be formulated as a bi-level program with continuous variable(congestion toll) such that the upper level problem is for maximizing the NEB in elastic demand, while the lower level is for describing route choice of road users. The bi-level CNDP is intrinsically nonlinear, non-convex, and hence it might be difficult to solve. So, we suggest a heuristic solution algorithm, which adopt derivative information of link flow with respect to design parameter, or congestion toll. Two example networks are used for test of the model proposed in the paper.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.1
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• pp.105-114
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• 2016

With approximately 20 million transportation card data entries of the metropolitan districts being generated per day, application of the data to management and policy interventions is becoming an issue of interest. The research herein attempts a model of the possibility of dynamic demand change predictions and its purpose is thereby to construct a Dynamic Passengers Trip Assignment Model. The model and algorithm created are targeted at city rail lines operated by seven different transport facilities with the exclusion of travel by bus, as passenger movements by this mode can be minutely disaggregated through card tagging. The model created has been constructed in continuous time as is fitting to the big data characteristic of transport card data, while passenger path choice behavior is effectively represented using a perception parameter as a function of increasing number of transfers. Running the model on 800 pairs of metropolitan city rail data has proven its capability in determining dynamic demand at any moment in time, in line with the typical advantages expected of a continuous time-based model. Comparison against data measured by the eye of existing rail operating facilities to assess changes in congestion intensity shows that the model closely approximates the values and trends of the existing data with high levels of confidence. Future research efforts should be directed toward continued examination into construction of an integrated bus-city rail system model.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.70-81
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• 2020

Point-by-point data, which is abundantly collected by vehicles with embedded GPS (Global Positioning System), generate useful information. These data facilitate decisions by transportation jurisdictions, and private vendors can monitor and investigate micro-scale driver behavior, traffic flow, and roadway movements. The information is applied to develop app-based route guidance and business models. Of these, speed data play a vital role in developing key parameters and applying agent-based information and services. Nevertheless, link speed values require different levels of physical storage and fidelity, depending on both collecting and reporting intervals. Given these circumstances, this study aimed to establish an appropriate collection interval to efficiently utilize Space Mean Speed information by vehicles with embedded GPS. We conducted a comparison of Probe-vehicle data and Image-based vehicle data to understand PE(Percentage Error). According to the study results, the PE of the Probe-vehicle data showed a 95% confidence level within an 8-second interval, which was chosen as the appropriate collection interval for Probe-vehicle data. It is our hope that the developed guidelines facilitate C-ITS, and autonomous driving service providers will use more reliable Space Mean Speed data to develop better related C-ITS and autonomous driving services.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.205-215
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• 2008

As static traffic assignment has reached its limitation with ITS policy applications and due to the increase of interest in studies of ITS policies since the late 1980's, dynamic traffic assignment has been considered a tool to overcome such limitations. This study used the Dynameq program, which simulates route choice behavior by macroscopic modeling and dynamic network loading and traffic flow by microscopic modeling in consideration of the feasibility of the analysis of practical traffic policy. The essence of this study is to evaluate the feasibility for analysis in practical transportation policy of using the dynamic traffic assignment technique. The study involves the verification of the values estimated from the dynamic traffic assignment with South Korea's expressway network and dynamic O/D data by comparing results with observed link traffic volumes. This study used dynamic O/D data between each toll booth, which can be accurately obtained from the highway Toll Collection System. Then, as an example of its application, exclusive bus-lane policies were analyzed with the dynamic traffic assignment model while considering hourly variations.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.91-102
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• 2003

There are two goals in this paper. The one is development of existing CA(Cellular Automata) model to explain more realistic deceleration process to stop. The other is the application of the updated CA model to forecasting simulation to predict short term link travel time that takes a key rule in finding the shortest path of route guidance system of ITS. Car following theory of CA models don't makes not response to leading vehicle's velocity but gap or distance between leading vehicles and following vehicles. So a following vehicle running at free flow speed must meet steeply sudden deceleration to avoid back collision within unrealistic braking distance. To tackle above unrealistic deceleration rule, “Slow-to-stop” rule is integrated into NaSch model. For application to interrupted traffic flow, this paper applies “Slow-to-stop” rule to both normal traffic light and random traffic light. And vehicle packet method is used to simulate a large-scale network on the desktop. Generally, time series data analysis methods such as neural network, ARIMA, and Kalman filtering are used for short term link travel time prediction that is crucial to find an optimal dynamic shortest path. But those methods have time-lag problems and are hard to capture traffic flow mechanism such as spill over and spill back etc. To address above problems. the CA model built in this study is used for forecasting simulation to predict short term link travel time in Kangnam district network And it's turned out that short term prediction simulation method generates novel results, taking a crack of time lag problems and considering interrupted traffic flow mechanism.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.105-115
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• 2009

According to the accident statistics published by the National Police Agency in 2007, the number of commercial vehicle(city, suburb and other buses) accidents consumes 3.5 percent of the total number of traffic accidents in this year. Since the commercial vehicles are responsible for not only the drivers but also the passengers, it leads more serious social and economic problems. There have been various forms of systems such as a digital speedometer or a black box to meet the social requirement for reducing traffic accidents and safe driving. however the system based on the data after accident control the driver by analyze dangerous drive behaviors, so there is a limit to control driver in real-time. Also speedometer currently managed provide the driver warning information in real-time, but using only the speed of vehicle and RPM information regardless of actual dangerous drive behaviors, disappear the effectiveness. In this study performed a simulation for drivers in general using a simulator programed with dangerous driving types we had developed in the previous study and judging the types. It'd be more effective system to provide the drivers warning information using weight valued in this study. However in this study is limited to apply weight as a result of simulation of drivers in general in actual situation should be made up the deficit based on information of driving type of actual commercial vehicles.

• Journal of Korean Society of Transportation
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• v.15 no.2
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• pp.7-23
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• 1997

본 연구의 목적은 설문조사를 통해 주민들이 실정에 맞는 거주자우선주차제의 실행 요건을 결정하는데 있다. 연구의 구성은 제2장에서 거주자우선주차제의 이론적 배경을 검토 하고, 제3장에서는 실행요건의 결정을 위한 연구분석의 틀을 제시하며, 제4장에서는 설문조 사의 방법과 조사내용에 대한 분석결과를 제시한다. 마지막으로 제5장에서는 결론과 정책건 의로 맺음한다. 이론적으로 분석결과 거주자우선주차제는 주차수요관리와 주차장공급촉진이 라는 2원적인 목표를 내재하고 있는 것으로 나타났다. 그결과 허가요금, 시행시간대 등의 실 행요건을 결정하는데 있어서 다양한 외부요인들을 고려하여야 할 필요가 있으며, 외부요인 들은 거주자들의 사회경제적 특성, 주거환경적특성, 주차행태적 특성, 기타특성 들로 구성된 다. 실행요건을 결정하기 위해 주민들에 대한 설문조사를 실시하였고 그 분석결과는 다음과 같다. 1) 요금수준 결정시 차고지 공급 목적일 경우 높은 수준의 요금을 부과하되 지역적 소득수준을 감안 하여야 하며, 목적이 수요관리에 있을 때는 외부인에 대한 규제만 하면 되 기 때문에 주민들에게는 무료이거나 가능한 낮은 요금을 징수하는 것이 바람직하다. 2) 공 간적 범위는 주민들의 근거리주차 선호 때문에 블록단위 또는 세가로를 중심으로 시행하되, 집앞돌폭이 4m 미만이거나 8m 이상일 경우에는 공간적 범위를 넓게 잡는 것이 바람직 할 것이다. 3) 주차면 배정은 독점적 사용권을 부여하는 방식이 공공재의 사유화라는 부작용 및 주차면의 비효율적 사용이라는 측면이 있기 때문에 가능한 공동이용방식을 채용함이 바 람직 한 것으로 나타났다. 4) 외부인 주처허가는 전용주택가 지역에서는 허용하여도 그리 큰 문제는 없을 것이나, 외부인 주차수요가 많은 지역에서는 무조건적 허락보다는 요금지불, 주차확인증과 같은 제도적 보완을 통해 허용해야 한다. 5) 시행시간대 결정시 전용주거지역 에서는 야간만 실시하여도 문제가 없으나 그외 지역에서는 주차수요를 고려하여 주간 또는 전일로 시행할 필요가 있다. 특히 주차문제가 하루종일 발생하는 경우와 출퇴근시 주차문제 가 많은 곳에서는 하루종일 시행할 필요가 있다. 그러나 차고지 확보율이 지나치게 낮은 곳 에서는 야간시 주민반대에 부디칠 가능성이 크기 때문에 차고지 여건이 개선될 때 까지는 시행을 보류할 필요가 있을 것으로 판단된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.92-101
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• 2012

Trip demands and patterns on weekends have been changed significantly over the past decade due to the income growth and the spread of the 5-day workweek in Korea. The increased weekend trips for shopping, leisure activities, entertainment and friendship have exacerbated traffic congestion in major highways or principal arterial roads from Friday afternoon through Sunday. Therefore, it is necessary to focus on travel demand forecasts and transport policies for weekend trips by investigating specific characteristics of the trips. Previous research efforts focus on simple analysis of characteristics of weekend trips and comparison of travel characteristics between weekdays and weekends. The paper analyzes the differences between weekday and weekend trips via statistical analyses to derive multiple types of characteristics of weekend trips, and develops Tobit models to identify key factors that may affect the number of trips, using Seoul city's weekend trip survey data in 2006. The model results show that weekend trips appear differently from weekdays by household or individual characteristics. Age, residence area and type of residence affected the number of trips, regardless of the type of the day, whereas gender, occupation, income, presence of household vehicle showed different impacts on trips between weekdays and weekends.