PURPOSES : This study presents a general guideline for the initial management of traffic signal timings in response to traffic incidents, prior to the implementation of specific treatments in detail. The proposed solution includes a set of optimal reductions in the green time rates at three signalized intersections upstream. METHODS : To account for the various traffic and incident conditions that may be encountered, a total of 36 traffic-condition scenarios were prepared. These scenarios encompass a wide range of conditions, from unsaturated to near-saturated conditions, and were designed to provide a comprehensive understanding of the impact of traffic conditions on signal timing. For each of the traffic conditions, all 27 traffic signal timing combinations were subjected to testing. A total of 972 simulation analyses were conducted using the SUMO model. The results indicated that the scenario with the lowest control delay was the optimal choice. RESULTS : The results indicated that the most effective initial management for the traffic incident would be to reduce the green signal timings by 20% at the first two upstream intersections and by 40% at the third intersection. CONCLUSIONS : We propose reducing the green times by 20% at the first and second intersections and by 40% at the third intersection as the initial response of the traffic signal control center when a traffic incident occurs.

PURPOSES : This study investigates the effects of three different three-color arrow traffic light operations on right-turn vehicles at intersections in Busan Metropolitan City. METHODS : Intersections in this study were categorized as general intersections (Type 1), intersections with right-turn pockets (Type 2), and intersections with scramble crosswalks (Type 3), and were investigated in terms of the efficiency (i.e., control delay) and safety (i.e., number of conflicts) of right-turn vehicles by employing VISSIM 2023 and SSAM3. RESULTS : From a mobility perspective (i.e., control delay), the protected/permitted operation outperformed the other two methods at the three types of intersections. The protected operation, similar to the results of the protected/permitted operation, was also superior to the permitted operation in terms of safety (i.e., number of conflicts). CONCLUSIONS : Protected/permitted operation has been proven to be a more efficient and safer measure than other operation methods for alleviating the problems of protected right-turn operation, which is currently implemented without three-color arrow traffic lights.

PURPOSES : This paper proposes an artificial neural network (ANN)-based real-time traffic signal time design model using real-time field data available at intersections equipped with smart intersections. The proposed model generates suitable traffic signal timings for the next cycle, which are assumed to be near the optimal values based on a set of counted directional real-time traffic volumes. METHODS : A training dataset of optimal traffic signal timing data was prepared through the CORSIM Optimal Signal Timing program developed for this study to find the best signal timings, minimizing intersection control delays estimated with CORSIM and a heuristic searching method. The proposed traffic signal timing design model was developed using a training dataset and an ANN learning process. To determine the difference between the traditional pre-time model primarily used in practice and the proposed model, a comparison test was conducted with historical data obtained for a month at a specific intersection in Uiwang, Korea. RESULTS : The test results revealed that the proposed method could reduce control delays for most of the day compared to the existing methods, excluding the peak hour periods when control delays were similar. This is because existing methods focus only on peak times in practice. CONCLUSIONS : The results indicate that the proposed method enhances the performance of traffic signal systems because it rapidly provides alternatives for all-day cycle periods. This would also reduce the management cost (repeated field data collection) required to increase the performance to that level. A robust traffic-signal timing design model (e.g., ANN) is required to handle various combinations of directional demands.

PURPOSES : This study proposes brief guidelines for traffic engineers in the field to refer to when operating tram priority signals based on the "early green" and "green extension" methods. METHODS : A set of VISSIM simulation analyses was conducted considering various traffic and control conditions in a hypothetical corridor consisting of two signalized intersections. The traffic conditions were varied at five different levels. The control conditions were varied at twenty-five levels by changing the tram priority traffic signal control parameters, i.e., the early green unit time and green extension unit time. A total of 125 simulation runs were from these combinations. A set of optimal signal timings for ordinary non-tram vehicles was prepared with TRANSYT-7F and implemented for the simulation. A tram priority signal control module based on VISVAP was exclusively developed for this study. RESULTS : As expected, no specific trend was found in the relationship between the two tram priority control parameters (early green time and green extension time). However, a trend was observed when assuming that the early green and green extension operations were mutually exclusive. Specifically, an inverse trend appeared between the tram priority control parameter values and level of congestion according to the performance measure (average network delay). CONCLUSIONS : For the early green control parameters, it is better to provide six seconds when undersaturated and four seconds when near-saturated. For the green extension control parameter, four seconds is suitable.

PURPOSES : In this paper, pedestrian-oriented time assured traffic operation (POTATO), adopted in Korea at a single crossing pedestrianoriented operating area, is explored and applied to a simulation experiment and test site to verify the operation efficiency. METHODS : Three candidate plans are presented as a method to operate pedestrian-oriented signal operations that can overcome the restrictions on signal controllers in Korea. The selected POTATO and TOD signal operations were compared and analyzed. The delay and pedestrian queues, present length, and number of times were used as comparative indices. RESULTS : Scenario-specific simulations confirmed that the delay, compared to TOD signal operation, was reduced by up to 5 s/ped depending on the vehicle traffic volume and the number of pedestrians. For the vehicle delay, the results increased up to 8.99 s/veh, depending on the traffic volume of the vehicles and pedestrians. As a result of the test site operation, POTATO operation improved by 5.12 s/ped (approximately 46.69% improvement) compared to TOD operation in the hours commuting to school and by 2.84 s/ped in the hours commuting from school (approximately 51.13% improvement). In case of vehicle delay, the delay increased by 2.35 s/veh (approximately 64.39%) in the hours commuting to school and 1.20 s/veh (approximately 21.11%) in the hours commuting from school compared to the TOD operation. CONCLUSIONS : Through simulations and test site pilot operation verifications, the effects of pedestrian delay improvement were more positive if POTATO proposed in this study was low in vehicle traffic.

PURPOSES: This paper presents the development and evaluation of the smart hardware-in-the-loop systems (SMART-HILS) that evaluate traffic signal operations of a new real-time traffic signal control system called SMART SIGNAL at the traffic management center (TMC) level. METHODS: The layouts of the hardware and software components of the SMART-HILS were introduced in this study and its performance was tested using real-time traffic signal operation algorithms embedded in the SMART SIGNAL control server by utilizing the VISSIM simulation model. In this study, the SMART-HILS management software was developed using .NET programming language. Fewer random seed numbers were used for the test scenarios by conducting statistical tests to address the shortcomings of a longer time due to the adoption of the simulation time as the real-time by the TMC server. RESULTS : It was determined that SMART-HILS can communicate with TMC and VISSIM for both upload and download directions within acceptable time constraints and evaluate new design algorithms for traffic signal timing. CONCLUSIONS : In practice, traffic engineers can utilize SMART-HILS for testing the traffic signal operation alternatives before their selection and implementation. This application could increase the productivity of traffic signal operation.

PURPOSES: We studied the signal operation method with a focus on swift evacuation of people from disaster-affected urban areas. METHODS: We selected Yeouido, which is at a high risk of being affected by natural disasters, as the urban area in our study. The analysis time for the Yeouido network was divided into four stages of six hours each, based on the traffic characteristics. The disaster scenarios were divided into small-scale and large-scale, and the analysis time and the disaster scale were set as the variables. RESULTS: From the analysis, it was found that the evacuation efficiencies were similar in the cases of entry control and increasing the green light duration for the main direction. However, the most effective approach is to apply entry control in case of disasters occurring at dawn and in the evening, with relatively low traffic volume. The most effective method is to increase the green light duration for the main direction of the main line in the time zone. CONCLUSIONS: As the scale of the disaster and the traffic volume increase, there is a limit on the extent to which the evacuation time could be reduced through signal operation. Therefore, signal control is most effective when the traffic volume is low and the disaster scale is small.

PURPOSES : In this study, analyze the characteristics of IOC indicator 'threshold' which is needed when evaluating the traffic signal operation status with ESPRESSO in various grade road traffic environment of Seoul metropolitan city and derive suggested value to use in field practice. METHODS : Using the computerized database program (Postgresql), we extracted data with regional characteristics (Arterial, Collector road) and temporal characteristics (peak hour, non-peak hour). Analysis of variance and Duncan's validation were performed using statistical analysis program (SPSS) to confirm whether the extracted data contains statistical significance. RESULTS: The analysis period of the main and secondary arterial roads was confirmed to be suitable from 14 days to 60 days. For the arterial, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 25 km/h as the critical speed for AM peak hour and night non peak hour. As for the collector road, it is suggested to use 20 km/h as the critical speed for PM peak hour and weekly non peak hour. It is suggested to use 30 km/h as the critical speed for AM peak hour and night non peak hour. CONCLUSIONS : It is meaningful from a methodological point of view that it is possible to make a reasonable comparative analysis on the signal intersection pre-post analysis when the signal operation DB is renewed by breaking the existing traffic signal operation evaluation method.

최근 우리나라는 기상이상으로 인한 자연재해 현상의 발생으로 재난지역 인근 도로의 도로 차단, 파손 등의 상황이 발생한다. 재난 발생 시 위험구역 내부의 도로 손상 및 단절로 인하여 주변 일대의 교통이 마비가 되는 현상이 발생한다. 이런 현상을 예방하기 위하여 재난 발생 시 신속한 대피를 위한 신호운영 기법 연구를 진행해야 한다. 재난의 종류에는 크게 폭설, 우박, 폭풍, 지진 등의 자연재난과 테러, 불법점검, 폭팔물 사고, 건물 붕괴 등 사회적재난으로 나뉘어져있다. 예전 2000년대에 도심에서 발생한 우면산 산사태, 강남역 침수 등은 자연재난으로 도로 폐쇄로 인한 소통마비 뿐 아니라 사고로 인한 많은 인적, 재산적 피해가 발생하였다. 피해의 주요 원인인 소통마비는 재난 발생 시 차량의 신속한 대피를 위한 신호운영 기법이 없어 도로에 방치되어서 발생하였다. 재난에서 시민들의 안전을 위해서는 빠른 대피가 우선시 되어야 하며 위험지역으로부터 신속한 대피를 위한 신호운영기법이 필요하다. 차량의 집중으로 인한 소통마비를 방지하고 위험지역으로 진입하는 차량을 다른지역으로 우회시켜 최단시간으로 대피할 수 있게 하는 것이 연구의 목표이다. 비상신호제어 전략은 다음과 같은 원칙을 준수하도록 한다. ① 차량이 재난이 발생한 위험지역으로 진입하지 않도록 한다.. ② 회전수를 최소화하여 주행시 발생할 수 있는 손실시간을 최소화한다. ③ 회전이 필요할 경우 가능한 신호에 따른 손실이 적은 우회전을 우선으로 한다. ④ 전단계에서 탐색된 경로를 이용하는데 방해되는 제어가 없어야 한다. 위의 원칙을 기본원칙으로 하여 신호운영을 1과 2로 나누어 분석을 시행하도록 한다.

국내 평면교차로 설계지침에서“평면교차로란 도로와 도로가 서로 교차 또는 접속되는 공간 및 그 내 부의 교통시설물을 말하는 것으로 교차로의 기하구조, 운영방법 등에 따라 운전자가 통행노선을 선정하는 의사결정 지점이 된다.”로 정의하였다. 교차로의 운영에 따라 파급효과는 연계 노선 전체의 도로에 중요 한 영향을 미치기 때문에 교차로 설계는 매우 중요한 문제이다. 그러나 현 지침에서는 각 교통운영 방안 별 도로･교통조건을 명확하게 제시하지 않았고“교통량 증가에 따라 순차적으로 시행”한다는 정성적 조 건만 제시하였다. 또한 경찰청의 ʻ국내 교통신호기 설치･관리 매뉴얼(2011)ʼ에서도 국내 도로･교통 여건에 대한 적정성 검토없이 미국 MUTCD(2009)의 기준 1(최소 차량 교통량)과 동일한 기준을 준용하고 있다. 그러나 이러한 미국 기준도 이론적 배경 부족 및 주관적 판단에 결정되기 때문에 지속적으로 문제점 지적 및 개정 필요성을 지속적으로 지적해 왔다. 따라서, 본 연구에서는 현 관련 기준에서 제시한 최소 교통 신 호등 설치 기준(차로수, 주도로/부도로 교통량)에 대해 시뮬레이션(VISSIM, Synchro) 및 현 운영중인 교 차로를 대상으로 적정성 분석 및 최소 기준을 제시하였다. 또한 차로 수 및 주도로/부도로 교통량 조건이 외에 다른 도로･교통조건(교차로 형태(3지교차로, 4지교차로), 교통량 분포 비율, 좌회전 교통량 비율)을 고려하여 교차로 운영효과를 추가로 분석하였다. 이러한 결과를 토대로 교통 신호등 설치 기준에 대한 재 정립 방향을 제시하였다. 시뮬레이션 결과, 국내에서 제시한 교통 신호등 설치 기준 값은 과다하게 설정 된 것으로 나타났으며, 이로 인해 조기에 교통 신호등 설치됨으로써 불필요한 지체 발생 혹은 불필요한 유지관리 비용 발생 등 비경제적으로 교차로가 운영될 가능성이 높은 것으로 나타났다. 또한 현 기준에서 반영하지 못한 교차로 형태(3지교차로와 4지교차로), 방향별 교통량 분포 비율, 좌회전 교통량 비율도 교 차로 운영 방식에 어느 정도 영향을 미치는 것으로 나타났다.

회전교차로의 운영 효율성과 안전성과 같은 장점은 국․내외 많은 연구에서 논의되고 있다. 이런 회전교차 로의 장점 중 높은 운영 효율은 신호 대기로 인한 불필요한 제어지체를 최소화시키기 때문에 발생한다. 하지 만 일정 교통량 이상의 경우에는 교차로 내 잠긴 현상 등으로 인해 지체가 발생하여 오히려 운영 효율이 낮 아진다. 이런 이유로 회전교차로는 많은 장점에도 불구하고 활발한 도입이 이루어지고 있지 않은 상황이다. 회전교차로 전환의 국내 기준은 회전교차로 설계지침(국토해양부, 2010)에 나타나 있다. 회전교차로 설 계지침에서는 회전교차로 전환 기준을 일교통량 1차로형 12,000대/일 이하, 2차로형 20,000대/일 이하, 첨두시 진입로의 차로당 교통량 125~450대/시, 좌회전 비율 30% 미만으로 제시하고 있다. 이처럼 설계 지침 상의 교통량 기준은 기초적인 기준을 제시하고 있으며, 매우 보우적인 기준을 적용시키고 있다. 회전교차로에서 많은 교통량을 처리할 수 있는 대표적인 방안은 신호 동시 운영 회전교차로의 도입이 다. 하지만 신호 운영 회전교차로는 신호교차로와 마찬가지로 불필요한 제어지체를 발생시킨다. 이소영 등(2012)은 이런 문제점을 해결할 수 있는 방안으로 회전교차로에 램프 미터링 시스템 도입을 제안하였으 나, 이는 많은 비용이 소요될 것으로 판단되어 다른 운영 형태와의 효율성 비교가 필요하다고 판단된다. 이에 이 연구에서는 신호교차로와 회전교차로를 교대로 운영하는 교차로를 제안하고 운영 효율성을 분 석하고자 한다. 연구의 목적은 회전교차로에 첨두시 신호 운영 방안을 제안하고, 지체 분석을 통해 이런 교차로의 운영 효율 측면을 분석하는데 있다. 연구의 흐름은 다음과 같다. 첫째, 문헌연구를 통하여 회전교차로의 특성 및 제약 조건 등을 살펴보고, 국내외 연구를 고찰한다. 둘째, 국내 교통 운영 자료를 통해 회전교차로의 운영 특성을 분석한다.. 셋째, 설계 기준 및 교통량 자료를 토대로 신호 운영 시나리오를 구축하고, aaSIDRA를 통해 시나리오별 지체를 분석한다. 마지막으로 연구의 결과를 정리하고 향후 과제를 제시한다. 분석을 위한 시나리오는 표 1과 같다. 총 540개의 시나리오를 분석하였으며, 회전교차로 6 유형, 진입 교통량을 100대부터 1,500대까지 100대 간격, 6가지 회전 비율을 토대로 하였다.

PURPOSES : The purpose of this study is to propose delay-minimizing operation methodology of a signalized intersection based upon optimization of lane-uses on approaching lanes for an intersection. METHODS: For the optimization model of lane-uses, a set of constraints are set up to ensure feasibility and safety of the lane-uses, traffic flow, and signal settings. Minimization of demand to saturation flow ratio of a dual-ring signal control system is introduced to the objective function for delay minimization and effective signal operation. Using the optimized lane-uses, signal timings are optimized by delay-based model of TRANSYT-7F. RESULTS : It was found that the proposed objective function is great relation with delay time for an intersection. From the experimental results, the method was approved to be effective in reducing delay time. Especially, cases for two left-turn lanes reduced greater delays than those for a left turn lane. It is noticed that the cases for different traffic volume by approach reduced greater delays than those for the same traffic volume by approach. CONCLUSIONS : It was concluded that the objective function is proper for lane-uses optimizing model and the operation method is effective in reducing delay time for signalized intersections.

Abstract 1. 서론 2. 연구방법 3. 사고현황 및 특성 3.1 고령운전자의 교차로 교통사고 3.2 신호기 운영방법 및 작동상태에 따른 사고 특성 3.3 차로폭에 따른 사고 특성 4. 결론 5. 참고문헌