• 한국항만학회지
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• 제4권1호
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• pp.3-20
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• 1990

The Port of Pusan, the largest port in Korea, handled 23% of total sea borne cargo movement, 14% of imported cargo, 58% of exported cargo and 95% of container cargo in 1989. Also the port of Pusan has been played a key role in handing container cargo throughout the last 10 years. The paper is aimed to survey the effect of sea borne cargo movement to urban transportation, that is, to find traffic volume arising by general/bulk cargoes through the port and to estimate vehicle rated of container tractor tailer on the roads between terminal including conventional piers and ODCY, and finally the following results are obtained. (1) AADV of truck to transport general/bulk cargoes are 6,322 units in 1989,and routes penetrate into the center of city and pass through the most of urban arterials. (2) In the container transport, if HVEF is adopted to 3 of tractor trailer, AVR in each transport freeway 13.7%. (3) IF HVEF is adopted to 6 of tractor trailer. AVR are as follows: BooDoo-Ro 44.1%, WooAm-Ro 39.3%, SooYoung-Ro 17.8%, Urban freeway 20.3%. Based upon these results, the following suggestions were drawn : o ODCY scattered around the city should be unified in a few groups to raise port productivity. o Rail service for inland container transportation should be escalated to relieve urban traffic congestion. o Coastal feeder service between terminal and hinterland should be studied to restrict the penetration of container tractor trailer into the central parts in the urban areas. o Exclusive freeway system for effective container transportation should be implemented to reduce urban traffic delay.

• 대한교통학회지
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• 제24권3호
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• pp.29-37
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• 2006

도시고속도로의 반복정체는 발생시점과 지점이 거의 일정하므로 정체발생 예상 및 사전대응을 통한 효과적인 관리가 가능하다. 기존의 교통관리시스템에서는 패턴데이터를 이용하여 반복정체를 관리하고자하였으나 다변하는 도시 부교통에서는 적용하기 어려운 경우가 많았다. 본 논문에서는 반복정체 발생확률을 통계적 분포를 적용한 통행속도별 발생확률을 이용하여 구하고자 하였다. 반복정체 발생확률 추정을 통해 반복정체 발생시점 및 지속시간을 파악하고, 효과적인 사전대응 수립과 교통운영이 가능할 것으로 기대된다

• 대한토목학회논문집
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• 제26권1D호
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• pp.59-66
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• 2006

이 연구는 도시고속도로의 진입연결로 접속부내 선형의 밀도예측모형 구축에 관한 연구로서 실시간 교통특성분석과 선형의 밀도예측모형 구축 및 검증을 통해 밀도예측모형 구축에 있어서 결정계수($R^2$)값이 대체적으로 0.7이상으로 나타나 선형회귀모형구축에 상당히 높은 설명력을 보이는 것으로 나타났고, 선형모형검증에 있어서 상관계수(r)값도 대체적으로 0.8 이상으로 상당히 높은 상관성을 보이는 것으로 나타났다. 따라서 향후 선형의 밀도예측모형을 이용하여 도시고속도로의 진입연결로 접속부내 차량의 밀도추정 및 지체분석에 상당히 유효할 것으로 판단된다.

• 한국항만학회지
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• 제13권2호
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• pp.333-350
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• 1999

Today freeway is thought to be a very important transportation facility carrying tremendous traffic flow as the main corridor within the area of between the areas. However freeway is experiencing severe congestion and accidents by increased entrance ramp flow especially at peak time period. Ramp meters on the freeway entrance ramps that supply traffic to the freeway in a measured or appropriately regulated amount are needed for alleviating freeway congestion. Because ramp meters can be operated to discharge traffic at a measured or regulated rate thus maintaining more uniform speed on the mainline section maximizing the throughput to the freeway within the capacity of a downstream bottleneck and reducing the congestion related accidents. Thus the objectives in this study were to analyze the traffic characteristics on the freeway I-94 with ramp metering system before/after ITS technology in Detroit (Michigan) area compare shifts of the traffic characteristics on the freeway I-94 before/after ITS technology and finally suggest a better ramp metering strategy for the freeway system The following results were obtained: i)Flow occupancies and speeds on the mainline merge section of freeway were shown to be a big difference depending on the peak periods areas and directions based on the distribution of traffic flow characteristics on the freeway. ii)Reduced speed was shown to be more than 5 mph and ramp flow was also shown to be more than 240 vph at peak periods if there was the ramp metering system constructed on the freeway. iii)Ramp metering system was shown to be optimally operated on the freeway if ramp flow could be maximized within the range of over 900 vph and reduced occupancy could be also maximized by no more than 2 percent at peak periods. iv)The average flows on the freeway after the ITS technology were shown to be a decrease of over 20% depending on the peak periods areas and directions when compared with those flow on the freeway before the ITS technology. over 20% depending on the peak periods areas and directions when compared with those speeds on the freeway before the ITS technology. vi)The average metering rates on the freeway after the ITS technology were shown to be an increase of over 10% depending on the peak periods areas and directions when compared with those metering rates on the freeway before the ITS technology.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권9호
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• pp.405-418
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• 2016

최근, 다중 구역의 교통 정보를 이용한 가변 속도 제한(VSL) 결정 방법이 연구되고 있다. 하지만 부정확한 VSL 시작 구간 및 거리 계산으로 더 심각한 정체현상을 유발하고 있다. 불안정한 VSL 시스템은 결국 도로의 정체 현상을 더 악화 시키고 결국 전체적인 교통 흐름의 악화로 발전될 수 있다. 본 논문은 다중 구간에서 안정적으로 동작할 수 있는 새로운 VSL 방법을 제안한다. 본 알고리즘은 가속도를 이용하여 정체 구간의 끝 부분으로 예상되는 예비 VSL 시작 구간(VSS)을 설정하고 정체 구간별 VSS를 선정한다. 선정된 VSS를 기준으로 VSL을 계산하고 정체구간으로 진입하는 차량을 통제한다. 제안하는 방법의 안정성 및 효율성 테스트를 위해 기존 시스템과 비교 실험을 진행한다. 실험을 통하여 제안하는 방법은 정확한 VSS 선정을 통해 기존 알고리즘의 문제점을 해결 하였고 총 이동시간이 1~2분 감소한 것을 확인하였다.

• 한국자동차공학회논문집
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• 제14권5호
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• pp.84-92
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• 2006

Freeway Corridors consist of urban freeways and parallel arterials that drivers can use alternatively. Ramp metering in freeways and signal control in arterials are contemporary traffic control methods that have been developed and applied in order to improve traffic conditions of freeway corridors. However, most of the existing studies have focused on either optimal ramp metering in freeways, or progression signal strategies between arterial intersections. There have been no traffic control systems in Korea that integrates the freeway ramp metering and arterial signal control. The effective control strategies for freeway operations may cause negative effects on arterial traffic. On the other hand, traffic congestion and bottleneck phenomenon of arterials due to the increasing peak-hour travel demand and ineffective signal operation may generate an accessibility problem to freeway ramps. Thus, the main function of the freeway which is the through-traffic process has not been successful. The purpose of this study is to develop an integrated control model that connects freeway ramp metering systems and signal control systems in arterial intersections. And Optimization of integrated control model which consists of ramp metering and signal control is another purpose. Optimization results are verified by comparison with the results from MATDYMO.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.8-15
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• 2007

Freeway corridors consist of urban freeways and parallel arterials that drivers can use alternatively. Ramp metering in freeways and signal control in arterials are contemporary traffic control methods that have been developed and applied in order to improve traffic conditions of freeway corridors. However, most of the existing studies have focused on either optimal ramp metering in freeways, or progression signal strategies between arterial intersections. There have been no traffic control systems in Korea that integrates the freeway ramp metering and arterial signal control. The effective control strategies for freeway operations may cause negative effects on arterial traffic. On the other hand, traffic congestion and bottleneck phenomenon of arterials due to the increasing peak-hour travel demand and ineffective signal operation may generate an accessibility problem to freeway ramps. Thus, the main function of the freeway which is the through-traffic process has not been successful. The purpose of this study is to develop an integrated control model that connects freeway ramp metering systems and signal control systems in arterial intersections. And Optimization of integrated control model which consists of ramp metering and signal control is another purpose. The design of experiment, neural network, and simulated annealing are used for optimization.

• 대한교통학회지
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• 제13권4호
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• pp.117-132
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• 1995

Peak-period congestion is a frequent occurrence on many freeways. Entrance-metering is an effective strategey in improving urban freeway traffic condition. This paper describes the prodecure to develop a computer program for proparing optimum ramp-metering stategies. Four existing ramp-metering optimaization models wer reviewed and evaluated in regared to their theories and actural performances. A optimization model was proposed in this paper. Final model takes aform of quadratic programming. The performance of the propeosed model wastest using FREFLO.

• 대한교통학회지
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• 제14권3호
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• pp.7-26
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• 1996

The estimation of real-time Origin-Destination(O-D) parameters, which gives travel demand between combinations of origin and destination points on a urban freeway network, from on-line surveillance traffic data is essential in developing an efficient ATMS strategy. On this need a real-time O-D parameter estimation model is formulated as a parameter adaptive filtering model based on the extended Kalman Filter. A Monte Carlo test have shown that the estimation of time-varying O-D parameter is possible using only traffic counts. Tests with field data produced the interesting finding that off-ramp volume predictions generated using a constant freeway O-D matrix was replaced by real-time estimates generated using the parameter adaptive filter.

• 한국도로학회논문집
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• 제18권4호
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• pp.77-82
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• 2016

PURPOSES : This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.