PURPOSES : The purpose of this study was to select recurring congested sections through an objective and reasonable method using intelligent transportation system (ITS) collection data as the first phase for controlling recurring congested sections. The selection is meant to enhance the utilization of national highway ITS collection data that are just managed as statistical data focusing on real-time traffic information or not satisfactorily used. METHODS : Hourly statistical data were obtained using travel speed with a 5-min frequency per information-providing section stored in the database server. The travel speed data were collected from field equipment in general national highway sections (793.8 km in 380 sections of 16 lines in 2017) in the Seoul Metropolitan Area through a literature review of congestion standards. Subsequently, the congested sections were drawn by dividing a month into weekdays and weekends, and the status of the monthly change and characteristics of the congested sections were analyzed. Based on the monthly data on the congested sections, monthly mean congested days and hours were calculated to select the significant recurring congested sections in 2017 and applied to the congestion frequency standard. RESULTS : Recurring congested sections occurred in seven sections (33.9 km) in three lines — in five sections (24.8 km) of two lines during the weekdays and in two sections (9.1 km) of one line during the weekends. The recurring congested sections selected based on the congested days and the recurring congested sections selected based on the congested hours were found to be the same. The recurring congested sections during the weekdays and weekends were not mutually duplicated and were divided. More congestion occurred during the weekdays than on weekends. CONCLUSIONS : In the seven sections selected as recurring congested sections, congestion occurred for more than six months during one year, indicating that congestion is concentrated in specific months, albeit continuously and repeatedly occurring over the long term. The recurring congestion section selection standard and method used in this study are considered to be objective and reasonable. If recurring congested sections are selected using the standard and method presented in this study using ITS collection data targeting general national highways nationwide in the Seoul Metropolitan Area, it is necessary to determine whether the standard and method reflect actual congestion situations satisfactorily. According to the result, a further study considering congestion speed and congestion frequency standards is needed.

PURPOSES : The purpose of this study is to perform traffic flow characteristics analysis for each point of the long-term work zones and to propose an estimated capacity method to support the establishment of traffic flow management strategies for the long-term work zones. METHODS : The study explained the difference in traffic flow characteristics between the short-term and the long-term work zones, and estimated the capacity of the long-term work zones. The analysis data were collected from five points of long-term work zones of the twolane highway. And VDS and DSRC data were applied to validate data. RESULTS : The characteristics of traffic flow at each measurement point in the long-term work zones showed some differences, among which the capacity was estimated as the starting point to be 1,200 pcphpl and the ending point, 1,400 pcphpl. The delay length was estimated by applying the queuing theory based on the capacity of the start point where the bottleneck starts. As a result of verifying the congestion length based on space diagram map analysis, it was determined that the capacity calculation value and estimation methodology presented in this study were appropriate. CONCLUSIONS : The long-term work zones are mixed with different characteristics of roads, so as the capacity values depending on the analysis location. Therefore, it is necessary to select analysis points and methodologies for estimating capacity and delay depending on the purpose of the analysis, such as estimating the maximum queue length or analyzing the maximum travel time. Through this study, it is expected that by providing accurate information on congestion in advance, road users can detour to other roads, and construction officials can adjust the construction plan to minimize congestion in the construction section.

지난 6월 30일 서울-양양고속도로의 마지막인 동홍천-양양 구간(71.7km)이 개통되었다. 이번 개통으로 서울에서 양양까지 이동거리는 25.2km, 주행시간은 40분, 사회적비용 약 2,000억 원 이상의 절감효과를 기대하고 있다. 그러나 개통 첫 주말 토요일, 새로이 선을 보인 국내 최초 상공형 휴게소인 내린천휴게소와 인제IC를 진출입하기 위한 차량들간의 엇갈림 발생(그림 1 참조)으로 강일기점 115k 지점 극심한 교통정체가 발생하였다. 약 두 시간의 교통정체는 본선 후방 약 6km까지 정체가 이어졌으며 그에 따른 원인부석 및 대책 마련이 대두되었다. 본 연구에서는 정체원인을 엇갈림 구간 병목현상, 본선 1차로 운행차량의 차로변경구간 길이 부족, 휴게소 진입부 혼잡으로 인한 대기행렬 발생 등으로 분류하였고 미시적 교통시뮬레이션 분석프로그램(VISSIM)을 활용하여 정체 개선방안을 도출하였다. 세부적인 정체 개선방안 도출을 위해 표. 1과 같이 분석하고 세부 시행방안을 검토하였다. 검토 및 분석결과 엇갈림구간 및 본선정체의 가장 큰 요인은 휴게소 진입 혼잡으로 확인 되었고, 휴게소 주차장 및 진출입동선 개선이 본선정체 개선에 상대적으로 높은 효과를 나타내었다. 또한 차로변경 사전유도(5km 전방부터 내린천휴게소 및 인제IC 진출차량을 2차로로 유도)의 정체개선 효과도 확인되었다.