중앙버스전용차로는 일반 도로 대비 높은 교통량과 반복적인 축하중이 작용하는 구간으로, 정차 및 출발 과정에서 발생 하는 국부적인 응력 집중으로 인해 포장 파손이 빈번하게 발생한다. 그러나 기존 도로 설계에서는 정적인 교통량을 기준 으로 축하중을 산정하여, 실제 교통 환경에서의 버스 유형별 차이, 재차 인원, 시간대별 하중 변화 등 동적인 요소를 충 분히 반영하지 못하는 한계가 존재한다. 이에 본 연구에서는 대중교통 빅데이터를 활용하여 중앙버스전용차로의 버스 유 형 및 시간대별 재차 인원을 반영한 새로운 축하중 산정 모델을 개발하였다. 이를 위해 서울시 열린 데이터 광장의 교통 정보를 활용하여 버스 유형 및 시간대별 재차 인원 데이터를 수집하고, 카카오맵 및 네이버 로드뷰 데이터를 이용해 결 측치를 보완하여 데이터셋을 구축하였다. 구축된 데이터셋을 활용하여 기존 ESAL(Equivalent Single Axle Load) 방식과 비교 분석한 결과, 새로운 축하중 모델에서는 기존 방식 대비 평균 111.8% 높은 축하중이 산정되었으며, 일부 구간에서 는 최대 128.9%까지 차이가 발생하는 것으로 나타났다. 이는 기존 포장 설계가 중앙버스전용차로의 실질적인 교통 하중 을 충분히 반영하지 못하고 있음을 시사하며, 추가적으로 버스 중하중의 가·감속의 영향을 고려한다면, 시간대별·노선별 실시간 축하중 변화를 보다 정밀하게 분석할 수 있으며, 이를 통해 과소 산정된 설계 하중을 보완하고 포장 공용성을 향 상시킬 수 있는 최적의 설계 및 유지보수 전략 수립이 가능할 것으로 기대된다.

도로 위 차량의 차로변경은 주변 차량의 움직임에 민감하게 반응해야 하며, 적절한 속도와 타이밍으로 수행하지 못할 경우 교통 흐름을 방해하고 부정적인 영향을 초래할 수 있다. 자율주행차량(Autonomous Vehicle, AV)은 이러한 문제를 해결하기 위해 주변 상황을 정확히 판단하고 인지하여 차로변경을 수행한다. 이때, 안전 관리 전략의 일환으로 최적화된 차로변경 주행 궤적을 제공함으로써 안전하고 효율적인 차로변경을 실현하는 것이 중요하다. 본 연구는 이러한 배경에서 주변 차량과 EGO 차량의 예측 주행 궤적에 기반한 확률론적 개념인 risk field를 계산하고, 이를 활용하여 차량의 종방 향 및 횡방향 안전 궤적을 제시하였다. 이를 위해 고속도로 드론 데이터를 활용하여 차량 간 상호작용 상황을 분석하고, 차로변경 시나리오 데이터를 분류하였다. 연구에서는 주행 속도와 차량의 경위도 등 1.1초 동안의 연속된 주행 데이터를 입력으로 사용하였으며, 다층 인코더-디코더 장단기 메모리 네트워크(EDLN) 모델을 통해 미래 6초 후 차량의 위치를 예 측하였다. 이후 장 이론(field theory)을 기반으로 한 risk field 모형을 통해 도로 위 각 지점의 위험도를 정량화하였다. 또한, 차량의 거동 제약, 주행 편의성, 그리고 안전성 제약 조건을 반영하여 안전 궤적을 생성하였다. 마지막으로, 생성된 궤적이 교통류 안전성에 미치는 영향을 평가하기 위해 예측된 주행 궤적(predicted trajectory)과 실제 주행 궤적(ground truth)을 비교 분석하였다. 평가지표는 대리 안전 지표(surrogate safety measure, SSM) 중 TTC(Time to Collision)와 PET(Post Encroachment Time)를 활용하였다. 본 연구는 제안된 안전성 정량화 및 궤적 생성 방법이 기존 방법론과 비 교하여 우수한 성능을 보임을 입증하였으며, 향후 자율주행차량 혼재 교통류 및 완전 자율주행 교통류에서 높은 효율성 과 안전성을 확보하는 데 기여할 것으로 기대된다.

본 연구는 자율주행자동차(AV)와 비자율주행자동차(HDV)가 혼재하는 교통환경에서 자율주행 전용차로 도입 시 차로변경구간 길이가 교통소통지표에 미치는 영향을 VISSIM 시뮬레이션을 통해 분석하였다. 분석을 위하여 도로구조 및 교통량, AV All-knowing, Cautious 주행행태를 반영하여 432개 시나리오를 구성하였다. 시뮬레이션 결과, 차로변경구간 길이가 증가할수록 교통 밀도와 지체시간은 유의 미하게 감소하였으며, 속도 및 통과교통량이 증가하는 효과를 보였으나, 자율주행 전용차로 도입 시 밀도와 지체시간이 증가하고 속도 및 통과교통량이 감소하는 등 일부 부정적 영향을 확인할 수 있었다. 향후 실제 도로 데이터를 반영한 분석을 통해 연구 신뢰성을 제 고할 필요성이 존재한다.

본 연구에서는 본선차로와 접속차로가 동일한 연속철근 콘크리트 포장(CRCP: Continuously reinforced concrete pavement)일 경우에 접속차로 CRCP의 종방향 철근의 거동을 분석하기 위해 창녕밀양건설사업단 1공구에서 시험시공을 수행하였다. 시험시공 구간에 균열유도장치와 철근 변형률계를 설치하여 접속차로 CRCP의 종방향 철근 거동을 분석하 였다. 분석 결과, 철근의 변형률은 균열부에서 가장 크게 발생하며 균열로부터 멀어질수록 감소하는 것을 확인하였다. 또 한, 변형률을 응력으로 환산할 경우 항복강도보다 현저히 낮아 접속차로 CRCP의 철근 배근은 우수한 공용성에 기여할 것으로 분석되었다. 이러한 결과를 통해 본선차로와 접속차로가 동일한 CRCP로 시공될 경우 포장 공용성을 보다 향상 시킬 수 있을 것으로 분석되었다.

Various road traffic signs are placed on the shoulder to inform drivers of the work situation ahead, speed limits, and lane changes in highway work zones. In this study, we analyze the effectiveness of a portable lane-change assistance system (PLCS) that can replace existing traffic signs from the perspectives of driver visibility and lane-change behavior. The existing highway work zone traffic management guidelines were regarded as a scenario without PLCS, and the case of replacing the existing traffic signs proposed by the manual with PLCS was set as a scenario with PLCS. For each analysis scenario, we analyzed the change in subjective awareness of traffic signs, perception accuracy of PLCS, advance lane-change rate, and lane-change location. The subjective perception analysis showed that the subjective perception change rate increased by 13.85% for two-lane highways and 5.29% for three-lane highways when PLCS was applied compared to that without PLCS. Regarding PLCS perception accuracy, all drivers correctly recognized the lane closure information for the two-lane case. Two PLCS are used in the three-lane case to provide lane-closure information. Regarding the first PLCS, all drivers correctly recognized lane closure information for the first lane sign, and 31 drivers correctly recognized lane closure information for the second and third lane signs. Regarding the second PLCS, all drivers correctly recognized lane closure information for the first and third lane signs, and 30 drivers correctly recognized lane closure information for the second lane sign in the second PLCS. Analysis of lane-change behavior showed that the proportion of advance lane changes increased by 31.25% in the two-lane case and 59.38% in the three-lane case with PLCS compared to that without PLCS. Additionally, lane-change locations where drivers performed lane changes from the starting point of the work zone area were analyzed. Drivers changed lanes at 653.68 m without PLCS and at 919.66 m with PLCS resulting in a 265.98 m increase in lane change location for the two-lane case. The drivers changed lanes twice in the three-lane scenario. Drivers changed lanes at 1014.41 m and 743.64 m without PLCS and at 1137.05 m and 868.24 m with PLCS, resulting in a 122.64 m and 124.60 m increase in the lane change location for the three-lane case. The proposed PLCS demonstrated a greater recognition capability than existing traffic signs and was effectively encouraged. This can be useful for replacing existing traffic signs in highway work zones.

This project aimed to understand the near-infrared (NIR), intensity, and reflectivity characteristics of LiDAR for measuring retroreflectivity and to understand the correlation between the characteristics of LiDAR and retroreflectivity. A 600 m-testbed was investigated using a survey vehicle equipped with LiDAR, and the testbed retroreflectivity and LiDAR data measurement values were compared. The reflectivity and intensity at night were not affected by sunlight compared with daytime, enabling stable data collection. However, NIR reacted very sensitively to sunlight, and the difference between daytime and nighttime NIR values was very large. In addition, by comparing the absolute error between the retroreflectivity and LiDAR data, we observed that the reflectivity was consistent with the data difference between day and night, and it was not significantly affected by sunlight. However, the intensity showed that the daytime measurement data were more scattered than the nighttime measurement data, resulting in low-precision collection stability caused by sunlight. An analysis of the correlation between retroreflectivity and LiDAR data using 40 data points revealed that the reflectivity and intensity data at night were highly correlated with retroreflectivity, with a P-value of less than 0.05. Reflectivity and intensity values at night correlate with retroreflectivity. The NIR light is sensitive to sunlight. Thus, it can be used as a solar correction index for future retroreflectivity analyses using intensity.

본 연구에서는 연속철근 콘크리트 포장(CRCP) 본선차로에 줄눈 콘크리트 포장(JCP) 길어깨가 적용되었을 경우에 타이바와 슬래브에 작용하는 응력을 완화시키고자 창녕밀양 고속도로 건설사업단 1공구에 타이바 규격 및 배치에 따른 3가지 경우를 구성하여 시험시공 을 실시하였다. 각 경우마다 타이바에 철근 변형률계를 설치하고 길어깨 포장에 콘크리트 변형률계를 설치하여 거동 분석을 수행하였 다. 분석 결과, 모든 경우에서 타이바와 콘크리트 슬래브의 응력이 강도에 비해 작게 분석되어 공용성에는 문제가 없음을 확인하였다. 향후 주기적인 거동 분석을 통해 최적의 타이바 배치 및 규격을 설계하여 콘크리트 포장의 공용성을 향상시키고자 한다.

PURPOSES : This study sought ways to connect urban above ground roads and underground roads to utilize urban space more efficiently in the development of underground roads, which are currently under development in order to alleviate problems caused by oversaturated above-ground roads. A simulation analysis was performed to develop an operation strategy that connects above-ground and underground roads to prevent congestion in above-ground areas such as entrances and exits from transferring to underground roads as well as to present its effectiveness. METHODS : Traffic efficiency analysis according to the operation strategy of above ground and underground roads was conducted using VISSIM, a microscopic traffic simulation software. The functions implemented in VISSIM were collected to set effectiveness analysis indicators for each underground road operation strategy. The Shinwol-Yeoui Underground Road was selected as the spatial scope of this study, and a surrounding road network was constructed. In addition, full-scale simulation analysis preparations were completed by performing network calibration based on the actual traffic attribute data of underground and surrounding surface roads within the construction scope. Accordingly, a traffic efficiency evaluation analysis was conducted based on the underground road operation strategy. CONCLUSIONS : Information on the increase in traffic volume within the Shinwol-Yeoui underpass was collected every 15 min. The analysis was divided into an analysis of the traffic situation within the underpass through demand control when the service level reached level D and an analysis of when demand control was not performed. It was found that demand control was necessary for the Shinwol-Yeoui Underpass when the internal traffic volume reached 2,500 vehicles/h. In addition, to analyze the spread of traffic and congestion owing to the weaving phenomenon caused by lane changes in the underpass, an analysis was conducted to observe the traffic improvement effect when full lane changes are possible for the Shinwol-Yeoui Underground Road, which currently has some lane-change-permitted sections. The analysis showed that both the maximum traffic volume and average travel speed showed better results when lane changes were allowed, and the communication situation at Yeoui JCT was found optimal.

PURPOSES : This study aims to develop a congestion mitigation strategy at lane drop bottleneck with low Connected and Automated Vehicle (CAV) penetration. METHODS : The proposed strategy is designed to assign a role of a moving bottleneck to CAVs to reduce low-speed lane changes at bottleneck locations, which are the main cause of bottleneck capacity drop. Through this, it aims to induce proactive upstream lane changes for Human-Driven Vehicles (HDVs,). Therefore, this study includes the control algorithm for CAVs, and the evaluation of the strategy assumes penetration rates of 5% and 10% in a Microsimulation VISSIM environment. The assessment is conducted by comparing the capacity drop and total travel time. Additionally, a sensitivity test for the parameter of the CAV control algorithm, reduced speed, is performed to find the optimal parameter. RESULTS : In this study, three scenarios, a) Base, b) CAV with no control, and c) CAV with control, are designed to evaluate the effects of the CAV control strategy. Analysis of segment density and lane change distribution reveals that the control strategy effectively prevented vehicle congestion due to the bottleneck effect. Additionally, the analysis of capacity changes before and after the bottleneck and total travel time shows the effectiveness of the control strategy. The sensitivity test on CAV control speed emphasized the importance of selecting an appropriate speed for maintaining efficient traffic flow. Lastly, as the CAV penetration rate increased, the control strategy exhibited greater effectiveness in mitigating capacity drop. CONCLUSIONS : The proposed strategy is intended for use at low CAV penetration rates and is expected to provide assistance in mitigating congestion at bottlenecks during the early stages of CAV commercialization. Furthermore, since the role of CAV in the strategy can be performed by CVs or even HDVs, it can be applied not only immediately but also in the near future.

PURPOSES : Because a driving simulator typically focuses on analyzing a driver’s driving behavior, it is difficult to analyze the effect on the overall traffic flow. In contrast, traffic simulation can analyze traffic flow, that is, the interaction between vehicles; however, it has limitations in describing a driver’s driving behavior. Therefore, a method for integrating the simulator and traffic simulation was proposed. Information that could be controlled through driving experiments was used, and only the lane-change distance was considered so that a more natural driving behavior could be described in the traffic flow. METHODS : The simulated connection method proposed in this study was implemented under the assumption of specific traffic conditions. The driver’s lane-changing behavior (lane-changing distance, deceleration, and steering wheel) due to the occurrence of road debris was collected through a driving study. The lane-change distance was input as a parameter for the traffic simulation. Driving behavior and safety were compared between the basic traffic simulation setting, in which the driver's driving behavior information was not reflected, and the situation in which the driving simulator and traffic simulation were integrated. RESULTS : The number of conflicts between the traffic simulation default settings (Case 1) and the situation in which the driving simulator and traffic simulation were integrated (Case 2) was determined and compared for each analysis. The analysis revealed that the number of conflicts varied based on the level of service and road alignment of the analysis section. In addition, a statistical analysis was performed to verify the differences between the scenarios. There was a significant difference in the number of conflicts based on the level of service and road alignment. When analyzing a traffic simulation, it is necessary to replicate the driving behavior of the actual driver. CONCLUSIONS : We proposed an integration plan between the driving simulator and traffic simulation. This information can be used as fundamental data for the advancement of simulation integration methods.

PURPOSES : The purpose of this study was to analyze the visibility of lanes according to the changes in the plane and longitudinal line of roads considering the horizontal and vertical diffusion angles of vehicle headlights at night. First, the visibility length of the lane was determined according to the plane linearity of the road such that it could be applied to simulation and visualization data. Second, the night vision length of the lane was established according to the longitudinal line of the road such that it could be applied to the simulation and visualization data. METHODS : In this study, each variable is first examined to consider the horizontal and vertical diffusion angles of the vehicle headlights. Second, the equation for the visibility of the lane by vehicle headlights in planar linearity is obtained, and the visibility of the lane is determined. Third, an equation is obtained for the visibility of the lane by vehicle headlights in longitudinal linearity. RESULTS : The results of this study are as follows. First, the visibility length of the lane in the section where the plane linearity of the highway existed at night was studied. In this case, the visibility length of the right and left lanes based on the vehicle decreased according to the plane linearity of the highway. Second, the visibility length of the lane in the section where the longitudinal line of the highway existed at night was investigated. In this case, the visibility length of the lane decreased according to the change in the longitudinal line of the highway. CONCLUSIONS : Considering the horizontal and vertical diffusion angles, the visibility length of the lane was determined according to the changes in the plane and vertical line of the road. It can be applied to simulation and visualization data. In general, the visibility length considering the spread angle of the vehicle headlights was shorter than the visibility length of the lane by the headlights; roads must be designed in consideration with the above result.

The lane departure warning device can not detect the lane to be driven in the future by sensing the departure of the lane passing by during driving and warning the driver. Considering the safe operation of the truck, it is also expected that the departure of the future lanes according to the dynamic weight and speed of the current truck should be predicted. This study attempted to predict whether or not to deviate from the lanes of curved roads to be driven in the future according to the current dynamic driving weight and speed in consideration of the safe driving of trucks.