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 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.

기상불량으로 인해 발생하고 있는 해양사고 중 해무 발생에 따른 시계제한은 선박의 좌초, 선저 파손 등의 사고를 유발하는 것과 동시에 사고에 따른 인명피해를 동시에 수반하고 있으며 이는 매년 지속적으로 발생하고 있다. 또한 해상에서의 저시정은 지역간 국소적으로 차이가 존재하는 경우에도 일괄적으로 여객선에 대한 운항 지연 및 통제 조치를 하고 있어 섬주민들의 교통수단 이용에 상당 한 불편을 초래하는 등의 사회적 문제로 대두되고 있다. 더욱이 이와 같은 조치는 지역적 편차나 사람마다 관측의 판단 기준이 상이하여 이를 객관적으로 정량화하지 못하고 있어 더욱 문제가 심화되고 있는 실정이다. 현재 각 항만의 VTS에서는 시정거리가 1km 미만인 경우 선박의 운항을 통제하고 있으며, 이 경우 저시정에 따른 해무 가시거리를 시정계 혹은 육안에 의한 목측(目測)에 의존하고 있을 정도로 객관적인 데이터 수집을 통한 평가에 있어서는 한계가 있다. 정부에서는 이와 같은 해양교통안전 저해요소를 해결하기 위한 일환으로 해 무 탐지 및 예측을 위한 해양기상신호표지 및 해상안개관측망을 구축하여 운용하고 있으나, 국지적으로 발생하는 해무를 관측하기 위한 시스템은 매우 부족한 현실적 어려움에 놓여있다. 이에 따라 본 논문에서는 해상에서의 저시정으로 인해 발생하고 있는 여러 사회적 문 제를 해결하기 위한 국내․외 정책동향에 대해 살펴보고, 이와 관련한 일반국민 및 현장 이해관계자의 인식 정도를 조사․분석하여 해무 에 따른 해상교통안전을 확보하기 위한 정부지원(해무 탐지 및 예측 기술을 기반으로 한 해상교통운영 체계 개발 등)의 필요성에 대한 기 초자료를 제공하고자 한다. 또한 이는 궁극적으로 해무로 인해 발생할 수 있는 해상안전 위험요소를 사전에 차단함으로써 보다 안정된 해상교통운영체계를 마련하는데 그 목적을 두고 있다.

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 study, we attempted to derive the optimal operation plan for urban public transportation routes by verifying changes in demand for use according to factors affecting public transportation. METHODS : First, the factors affecting changes in demand for public transportation were drawn. Second, the appropriate areas to be analyzed and their main routes were selected. Third, the basic data required for estimating public transportation traffic demand were collected through transportation card data. Fourth, basic networks and routes in TOVA were established for public transportation assignment. Finally, through traffic assignment, changes in usage demand owing to factors affecting bus routes were verified, and the optical operation plan was derived. RESULTS : Among the three routes selected for analysis, the rearranged B2 route increased by 662 from 6,142 to 6,804 per day, with the largest increase in daily demand. In addition, the number of stops increased with the access time, but there was no change in the average congestion. CONCLUSIONS : Through this study, it is believed that in can be used as the basic data on how to improve bus routes in local governments from the perspective of operators by analyzing the effectiveness of rearranging routes and drawing optimal operation measures.

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.

현재 일본 등 외국에서는 특별히 금지된 장소 이외에는 차량 운전자가 “보행자나 다른 차량의 정상적인 교통을 방해할 우려가 없다고 판단하 는 경우”도로의 중앙을 넘어 우회전·좌회전 또는 회전(유턴)할 수 있 도록 되어있다. 그러나 한국에서는 1984년 당시,“교통안전”을 확보하기 위해 좌회전은 원칙적으로 교통 신호에 따라서만 가능하도록 하고, 원활한“교통소통”을 도모하기 위해 필요한 경우에는 관할 지방경찰청장이 특별히 허용한 장소 에서만 제한적으로 좌회전을 허용하는 방식의‘비보호 좌회전’이라는 독특 한 제도를 도입하였다. 원래‘비보호’란 법의 보호를 받지 못한다는 의미이며, ‘비보호 좌회 전’은 도로의 중앙을 넘어 반대방면으로 진입하는 운전 행위이기 때문에 매우 위험하다. 따라서 종래에는 도로교통법령에‘비보호 좌회전’하다가 교통 사고가 발생하면 좌회전 차량 운전자에게“신호위반”의 책임을 지고 무거운 처벌을 받도록 규정함으로써 평상시 경각심을 가지고 조심스럽게 운전을 하도록 유도하고 있었다. 그런데 2008년경부터 경찰청은‘비보호 좌회전’과‘유턴’확대,‘비보호 겸용 좌회전’ 신설 등 주로“교통소통”위주의 시책을 적극 추진하였다. 그 과정에서“적신호시, 좌회전시 등”기존의 보조표지를 제거한‘유턴’허 용 지점이 많아졌고, 그 결과 교통사고가 빈발하자, 일부 지역에서는 기존의 보조표지를 제거한‘유턴’허용지점에 현행법상 아무런 근거도 없는‘비보 호’라는 새로운 내용의 보조표지를 부착하는 등 현재‘비보호’는 관련법 규정과 실제 운용 실태 간에 상당한 괴리와 혼동이 발생하고 있는 실정이다. 그중에서도 특히 2010년 8월에는 ‘비보호 좌회전’하다가 교통사고를 야기 한 운전자에게는 “신호위반”의 무거운 책임을 지도록 했던 기존의 근거 규정 도 삭제되었다. 그 결과 녹색 신호에 정상 진행하다가 반대방향 도로에서 갑자기 튀어나온 비보호 차량과 충돌하는 사고를 당한 피해 운전자 입장에서 는 가해 운전자가 종합보험에 가입되어 있는 경우, 현행 「교통사고처리특례 법」상 불기소로 가볍게 처리됨으로써 그에 따른 불만이 크게 고조되고 있다. 따라서 이러한 문제를 해소하기 위해서는 교통사고 발생 시, 당사자 간 여러 가지 중대한 책임과 의무를 초래하게 되는 법상 ‘비보호’관련 규정을 다음과 같이 시급히 정비 ․ 보완해야 할 필요가 있다. 첫째, ‘비보호’및 ‘유턴’의 개념을 법 제2조에 신설하고, 관련 규정을 개정․보완해야 한다. 둘째, 이미 활용되고 있는 ‘비보호 유턴’을 현실화하고, 그 근거 규정을 신설하여야 한다. 셋째, ‘비보호 좌회전 및 유턴’통행하는 차마 운전자에 대한 책임성을 강화해야 한다. 넷째, ‘비보호 좌회전 및 유턴’의 법적근거와 사고 야기에 따른 처벌규 정을 신설해야 한다. 다섯째, ‘비보호 유턴’관련 안전표지 및 노면표시를 신설하고, 비보호 허용지점 전방에는 ‘예고 노면표시’를 설치 ․ 운용해야 한다.