• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.90-99
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• 2020

The "Low Emission Zone" (LEZ) system restricts entry of vehicles with high air pollutants into city centers. Implementation of the system improves air environment around the world. Since 2012, operating restrictions have been applied to all of Seoul's metropolitan areas and some other metropolitan areas in the state. Beginning in December 2019, entry of 5th class vehicles to the central green transport zone of Seoul has been restricted. In this study we examine the status of operational restrictions in this zone, and predict the amount of traffic reduction expected when numbers of target vehicles are expanded in the future, we use data for each vehicle's emission grade: by region and 'Origin-Destination Traffic Volume'. After estimating the amount of traffic entering Seoul's 25 autonomous districts, by emission class, we propose a target region that may have a significant effect if target areas for automobile operation restrictions expand in the future.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.275-284
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• 1998

신호화 교차로는 한정된 시간 자원을 각 접근로별로 서로 다른 수요에 적절하게 효과적으로 배분함으로써 그 운영효율이 극대화될 수 있다. 현재 서울시 기존 전자신호시스템은 검지기체계를 갖추고 있으나 주로 시간대별 제어방식(TOD제어)을 사용하고 있다. 이에 대한 대안으로 실시간 교차로신호제어시스템인 이른바 첨단신호시스템이 개발되어 서울시 강남지역 61개소에서 시범운영중에 있다. 첨단신호시스템은 접근로별 수요에 따라 녹색시간을 배분하는 방식을 적용하고 있는데, 본 논문에서는 첨단신호시스템의 운영효율성을 평가하기 위하여 실제 교통수요와 운영녹색시간을 비교·분석하였다. 그 결과로 얻은 결론은 다음과 같다. 첫째, 방출차량에 의한 포화도의 비율을 고려하여 주기 및 녹색시간을 결정하는 첨단신호제어시스템의 알고리즘은 비포화시 직진이동류에 대한 녹색시간은 수요에 비해 과대산출운영되고 있다. 둘째, 좌회전의 경우 대기차량의 패턴이 불규칙할 때, 실시간 녹색시간제어기능이 미흡하다. 따라서, 향후에는 교통수요를 고려할 수 있는 알고리즘의 보다 심도있는 연구·개발이 요구되며, 또한 비포화 상황이 아닌 과포화 상황에도 적용될 수 있는 알고리즘의 개발이 이루어져야할 것으로 보인다.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.147-154
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• 2004

The purpose of this paper is to improve the existing phase split algorithm considering the minimum green time in COSMOS. In the case of a signalized intersection where two wide and narrow streets intersect each other, the time required for the pedestrian crossing is frequently longer than the time alloted to the through traffic on a minor street. In order to meet the minimum green time requirement for the pedestrian less time in alloted automatically to the left-turn traffic, creating heavy congestion on the left-turn approach. To solve this problem, this study suggests a new algorithm which shares the barrier using minimum green time and shares the burden with signal phases alloted to the crossing street traffic on the basis of the equal ratio of the degree of saturation, while maintaining the minimum green time requirement. The new algorithm was compared with the existing algorithm by using a microscopic simulation model for COSMOS evaluation developed at Ajou University. The simulation results show that the new algorithm produces better performance than the existing one.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.703-721
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• 2010

Railroad is the environment-friendly green growth transportation system and it needs connection and transfer system. Connection system can be a national core project centered in main railroad stations. If there is no transfer system for customers, it's very difficult to achieve green growth and the activation service for public transportation. This study will introduce the establishment of connection & transfer system and the activation methods between main stations in South Gyeongsang area (Changwon, North-Changwon, and Masan) and other transportation modes. These methods will be the model for connection & transfer system of main stations, and will be applied to adopt methods for customers' convenience of railroad public transportation.

• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.123-134
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• 2002

감응식 신호운영변수 설계에 관한 연구는 정주기식 신호운영변수 설계의 그것보다 그 수준이 현저히 미비하며 이는 감응식 신호운영 특성을 반영한 평가방법의 부재로 감응식 운영변수의 평가가 불가능하였기 때문이다. 본 논문은 최근에 소개된 평균 감응현시 녹색시간 추정 수리모형을 이용하여 Highway Capacity Manual (HCM) 지체도를 최소화하는 최대녹색시간의 설계방안을 제시한다. - '최소녹색시간'과 '단위연장시간'은 보행자 횡단시간 및 차량 차두시간 등 지역별 운전자/보행자의 특성과 관련이 있어 일반적인 최적화 설계 수리모형의 적용에 무리가 있어 제외한다. 제안된 설계방안은 감응식 운영논리를 토대로 감응현시 군의 평균녹색시간과 평균주기를 산정하며, HCM 지체도를 평가하고, 가능한 대안 중 지체를 최소화하는 최대녹색시간 운영변수 군을 '혼혈 유전자 알고리즘'으로 도출한다. 현장실험을 통해 도출이 불가능한 실제 최적치를 Corridor Simulation(CORSIM)모형을 이용하여 추정하였고 이를 제안된 설계방안으로 도출된 최대녹색시간 운영변수' 값들과 비교하였다. 비교결과 교차로 v/c 비율이 1.0 보다 낮을 시는 제안된 방법을 통해 설계된 최대녹색시간 운영변수 군이 최소 CORSIM 지체도를 산출하는 최대녹색시간 운영변수 군과 동일한 것으로, v/c비율이 1.0보다 높을 시는 다른 것으로 결과되었다. v/c비율이 1.0 보다 높은 경우는 정주기식 교차로 운영에 효율적이라 감응식 운영의 필요를 벗어나므로 제안된 최대녹색시간 설계방안은 감응식 신호운영 필요범위 내에서 효율적이다. 기존의 최대녹색시간 설계는 정수기식 최적녹색시간을 기준으로 최대녹색시간을 추정하며, 그러한 과정을 돕기 위하여 추정범위(설계자가 범위 내에서 임의로 선택함)를 제시하는 것이 기존의 연구임을 비교하면 본 연구에서 제안하고 있는 설계방법의 의미가 크다.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.33-42
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• 2012

This study proposed a model for estimating the unit value of social cost for mobile emission considering local geographical and social characteristics, together with a method to evaluate the air quality value. The model was built based on benefit transfer methods, the population density, and green space ratio of each area, which are reflected through independent variables. While applying the model, the unit value of social cost for mobile emissions in both densely populated areas of Seoul and Busan was found to be 18.68 times and 10.71 times higher than the national average, respectively. It is highly expected that this study can contribute to providing more reliable guidelines to decision makers when evaluating various green transportation policies and projects.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.243-250
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• 2016

As sustainable growth has been emphasized in the field of transportation, the railway system has been promoted as an environmentally-friendly transport mode. However, mode shifts from other transport modes to railway have been sluggish. In this context, to enhance the understanding of railway's competitive advantages and disadvantages, this research evaluates travelers'preferences for public transport modes for inter-regional trips: such understanding should make it possible to formulate effective policy for promoting railways. To this end, passenger recognition of competitive transport modes has been measured by applying multidimensional scaling analysis for six major inter-regional public transport services - KTX, ITX-Samaeul, Mugunghwa-ho, premium express bus, general express bus, and airline. As a result, we can conceptualize the recognition similarity in two-dimensional space, and understand how travelers perceive the six major transport modes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.5
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• pp.639-650
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• 2023

Economic development has resulted in the concentration of population and industry in the metropolitan area. Additionally, the Republic of Korea is experiencing this phenomenon, with more than half of the population living in the Seoul capital area. To alleviate this concentration of population, the Korean government implemented the new town development policy. Unfortunately, this has led to an increase in the commuting population, causing an imbalance in transportation services due to financial and policy differences in each region. This paper analyzes the level of user satisfaction with mega commuting in three aspects: mobility, accessibility, and connectivity. To objectively assess the level of user satisfaction, which is qualitative data, the Rasch Model is used to analyze the collinearity of user data. The results indicate that the level of user satisfaction differs by region, and service satisfaction with mobility is lower than that with accessibility and connectivity. Therefore, prior to the introduction of new town policies, it is necessary to develop metropolitan transportation infrastructure.

• Journal of Korean Society of Transportation
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• v.35 no.5
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• pp.447-457
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• 2017

This study aims to analyze the accidents of green mode bicycle. In pursuing the above, this study gave special emphasis on modeling the bicycle accidents reflecting the regional characteristics. The main results are as follows. First, the null hypotheses that the number of accident and ratio of serious injury and fatality (FSI) were the same over regions were rejected. Second, as the common variables, the number of bicycle was judged to have positive (+) impact to the accidents and the bicycle using ratio was inferred to increase the ratio of FSI. Third, the elderly population ratio among 3 factors which gave impact to the accidents of Si_A (city-county consolidation) was concluded to have the greatest elasticity. The developed area ratio between 2 factors in Si_B (city which is not consolidated) was, however, estimated to have the higher elasticity. Fourth, the number of car registration among 5 accident factors of Gun (county) was analyzed to have the greatest elasticity. Finally, the commuting trip ratio among 7 accident factors of Gu (district) was judged to have the greatest elasticity. This study can be expected to give some implications to regional policy-making related to bicycle.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.23-31
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• 2002

The headway of vehicles entering an intersection is closely related with the saturation flow rate and is a basic parameter required for determining the saturation headway and the start-up lost delay. Since such headway value reflects the drivers' behaviors and features of the intersection, all intersections don't have an equal value, but are affected by number and location of their lanes, changing types, local characteristics and time zone. Accordingly, this study attempted to suggest proper values on the basis of data by investigating headway in lanes. Number of exclusive through lanes was divided into single lane, double lanes and triple lanes, the locations of lanes were divided into inside lane, central lane and outside lane. As a result of investigating the headway, single through lane, double through lanes-inside lane, and triple through lane-outside lane showed as 1.73 sec., 1.71 sec. and 1.93sec., respectively. The result of calculating the area factor of business areas by fixing 1.00 for the residental area and applying relation between headway and saturation flow rate was 0.96. In the case of start-up lost delay lead dual left turn and directional separation were 1.41 sec. and 3.27 sec., respectively, showing the great difference. Therefore, different start-up lost delay according to changing type should be applied.