• Title/Summary/Keyword: spillback

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A Fuzzy Traffic Controller Considering Spillback on Crossroads

  • Park, Wan-Kyoo;Lee, Sung-Joo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.1-5
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    • 2001
  • In this paper, we propose a fuzzy traffic controller that is able to cope with traffic congestion appropriately. In order to consider such situation as loss of green time caused by spillback of upper crossroad, it imports a degree of traffic congestion of upper roads which vehicles on a crossroad are to proceed to. We constructed the equal-partitioned fuzzy traffic controller that uses the membership functions of the same size and shape, and modified the size and shape, and modified the size and shape of its membership functions by the membership function modification algorithm. In experiment, we compared and analyzed the fixed signal controller, the fuzzy traffic controller with the membership of the same size and shape, and the modified fuzzy traffic controller by using the delay time, the proportion of entered vehicles to occurred vehicles and the proportion of passed vehicles to entered vehicles. As a result of experiment, the modified fuzzy controller showed more enhanced performance than others.

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Development of Signal Control Strategy for Oversaturated Intersections Using Wayside Video Equipment (노변영상장비를 활용한 과포화 신호제어전략 개발)

  • Lee, Hyun;Kim, Won-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.12 no.4
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    • pp.11-21
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    • 2013
  • The conventional real-time signal control strategy for oversaturated situation generally requires a number of detectors at the intersection in order to identify the queue length at each approach. Also, existing strategy for the spillback has limited effect due to the temporal spillback control which only reduce the green split at the approach. In this study, a signal control system utilizing the imagery information from ITS roadside equipment is developed for operation of oversaturated intersections. The strategy calculates the saturation ratio based on the queue length extracted from ITS RSE, and designs the signal control variables according to the saturation ratio. The signal control strategy is divided into two phases: oversaturated and supersaturated. In oversaturated conditions, timing plan for main approach is optimized by the queue length. In oversaturated conditions where spillback might occur, the signal timing is designed in order to avoid the spillback. To increase field adaptability, the strategy is designed to adjust the split length, all-red-time, and clearance time, and keep the major signal control variables intact. The result of the simulation shows that in oversaturated conditions, the improvement is similar to the real-time signal control system. In case of, oversaturated conditions, however, the effect of the strategy is superior to that of a real-time system.

Design of prevention spillback agorithm using fuzzy rule

  • Hong, Yousik;Cho, Hyungki;Park, Chongkug
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.32-35
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    • 1996
  • Traffic signal cycle optimization is one of the most efficient ways for reducing fuel consumption and improving vehicle waiting time of highsaturated traffic conditions. But most research focused on lowsaturated traffic conditions. Only a few studies have researched traffic control for highsaturated traffic conditions. In this paper reviews the problem of conventional traffic signal system and creates optimal traffic cycle of at the bottom traffic intersection using 27 fuzzy rules. Moreover, to prevent spillback, it can adapt control even though upper traffic intersection has a different saturation rate, road length, road slope and road width.

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Adaptive Signal Control for Oversaturated Arterials (과포화 간선도로의 실시간 신호처리)

  • 최병국
    • Journal of Korean Society of Transportation
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    • v.15 no.3
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    • pp.111-130
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    • 1997
  • 교통수요가 용량보다 많아지면 신호교차로가 모든 교통량을 통과시키지 못하므로 시간이 갈수록 대기 행렬이 점점 길어질 것이다. 이러한 과포화상태에서는 늘어나는 대기행렬을 조절하지 못하면 결국에는 Spillback이 상류 교차로로 확대되어 최악에는 교차로에서의 모든 방향의 움직임을 정지시키는 Gridlock상태로까지 악화될 수 있다. 따라서 과포화 상태에서는 비포화 상태와는 달리 늘어나는 대기 행렬을 조절하여 통과 교통량을 최대화 시키는 것이 신호처리의 목적 함수가 될 수 있을 것이다. 6월호의 논문에서는 Static 한 상태의 과포화 간선도로를 신호처리에 의해 일정한 대기행렬을 유지하므로써 시스템을 최적화하는 알고리즘을 개발하였다. 그러나 과포화 간선도로의 교통수요는 매 Cycle 마다 Dynamic 하게 변하고, 과포화의 교통상황에서는 미미한 교통 변화가 우리가 염려하는 Spillback 을 야기시킬 수 있기 때문에 본 논문에서는 6월호에서 개발한 알고리즘에 기초하여 실시간으로 신호처리 하는 알고리즘을 개발하였다. 과포화 상태의 5개의 신호교차로를 가진 간선도로를 Simulation 하여 비교한 결과 본 논문에서 개발한 알고리즘이 PASSER II 나 TRANSYT 7F 보다 차량 한 대당 평균 운행시간이 각각 30%, 20% 줄어들었다.

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Development of a Traffic Simulation Model Applicable for Oversaturated (과포화 교통상태에의 적용을 위한 시뮬레이션 모형개발)

  • 안계형
    • Journal of the Korea Society for Simulation
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    • v.6 no.2
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    • pp.15-29
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    • 1997
  • Many studies have been performed and applied successfully for the control of undersaturated intersections, but most of them have been ineffective or invalid in oversaturated conditions. There has been relatively limited research in traffic control for oversaturated environments, and most has been too theoretical to be applied in a real system. Therefore, a traffic simulation model specifically designed for oversaturated arterial networks was developed. Two control objectives of traffic signal timing in oversaturated conditions were taken into consideration. One was to maximize the throughput, or the number of vehicles processed during a given time period. The other was to prevent queue spillback or to minimize the occurrence of queue spillback if inevitable.

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A Mainline Metering Strategy at Toll Plaza Considering Queue Imbalance Among Lanes (차로간 Queue 불균형을 고려한 Toll Plaza 본선미터링 전략)

  • Jang, Sunghoon;Lee, Yong-Gwan;Kho, Seung-Young;Lee, Chungwon
    • Journal of Korean Society of Transportation
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    • v.33 no.1
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    • pp.1-13
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    • 2015
  • This study aims to develop a mainline metering strategy considering queue imbalance among lanes that can reduce congestion at a toll plaza section by managing queue caused by mainline metering. The suggested strategy considers simultaneously optimizing the number of cars in merging area and managing queue by lane. This study analyzes the effectiveness of the strategy with respect to the average travel time and the occurrence rate of spillback using the PARAMICS. The results show that the suggested strategy has an effect on reducing congestion and improving operation efficiency at toll plaza. In particular, the congestion become more intensified when the length of waiting space is shorter; however, this study shows that the suggested strategy can relieve the congestion in that condition.

Development of A System Optimum Traffic Control Strategy with Cell Transmission Model (Cell Transmission 이론에 근거한 시스템최적 신호시간산정)

  • 이광훈;신성일
    • Journal of Korean Society of Transportation
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    • v.20 no.5
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    • pp.193-206
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    • 2002
  • A signal optimization model is proposed by applying the Cell-Transmission Model(CTM) as an embedded traffic flow model to estimate a system-optimal signal timing plan in a transportation network composed of signalized intersections. Beyond the existing signal-optimization models, the CTM provides appropriate theoretical and practical backgrounds to simulate oversaturation phenomena such as shockwave, queue length, and spillback. The model is formulated on the Mixed-Integer Programming(MIP) theory. The proposed model implies a system-optimal in a sense that traffic demand and signal system cooperate to minimize the traffic network cost: the demand departing from origins through route choice behavior until arriving at destinations and the signal system by calculating optimal signal timings considering the movement of these demand. The potential of model's practical application is demonstrated through a comparison study of two signal control strategies: optimal and fixed signal controls.

A Study on the Loop Detector System for Real-Time Traffic Adaptive Signal Control (실시간 교통신호제어를 위한 루프 검지기 체계 연구)

  • 이승환;이철기
    • Journal of Korean Society of Transportation
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    • v.14 no.2
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    • pp.59-88
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    • 1996
  • This study has determined optimal type, and location of loop detector to measure accurately traffic condition influenced by traffic variation with real time. Optimal type of loop detector for through vehicle at stop bar was determined by confidences of occupancy period, and nonoccupancy period, and so appropriate detector type for application to real time traffic control system has been decided on special loop detector.

    shows types and winding methods of existing detector (num1) and special detector (num 7,8) determined. It is desired that optimal location of through loop detector should be installed within 50cm of stop bar owing to vehicle behavior. And optimal location of loop detector for left turn vehicle is determined by left turn vehicle behavior on stop bar. In the case of install only one loop, it is desirable that within 20cm of stop bar. Both the special loop (1.8 × 4.0m : num 1.7) and existing loop (1.8 × 1.8m : num1) would be suitable. A location standard aspects, while regarding as economic, existing loop (1.8 × 1.8m : num1) would be suitable. A location of the queue detector and the spillback prevention detector considering the link length, the pedestran crossing is be or not and the estimation range of queue. And if the link length is shorter than 250m, locations of queue detector and spillback protect detector must be considered in the respect of queue management.

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Optimal Traffic Cycle using Fuzzy Look up Table Method (퍼지 Look up Table 방식을 이용한 최적신호주기산출)

  • 박종국;진현수;홍유식
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1996.10a
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    • pp.198-207
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    • 1996
  • Electro sensitive traffic system can't consider passenger car unit, so, it causes start up delay time and passenger waiting time. In this paper, it antecedently creates optimal traffic cycle of passenger car unit at the bottom traffic intersection. But, sometimes it can make mistakes due to changes in car weight, car speed, and control of feed-back data. Moreover, to prevent spillback, it can adapt control even though upper traffic intersection has a different saturation rate, road length, road slope and road width.

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Fuzzy Traffic Signal Light (퍼지 교통 신호등)

  • 홍유식;김승훈;김종수;박종국
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.1
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    • pp.76-81
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    • 2001
  • 전자교통신호등은 차량이 교차로에 많을 때에는 교통신호주기를 연장할 수 있고, 교차로에 차량이 적을 경우에는 교통신호주기를 단축할 수 있다. 그러나, 요즈음과 같이 교통체증이 많아서 평균주행속도가 10Km-20Km일 때에는 전자신호등의 기능을 수행할 수 없다. 본 논문에서는 퍼지 규칙을 이용하여 최단경로검색 및 최적 녹색시간 알고리즘을 제안한다. 컴퓨터 모의실험결과 앞 막힘 현상이 발생하는 경우에는 평균 승용차 대기시간 및 평균주행속도를 10%-32% 가량 개선시킬 수 있음을 입증하였다.

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