최근 자율주행 차량의 등장으로 인해 기존의 교통 시스템에 많은 변화가 생길 것으로 보이며, 운전자가 주행하던 차량과는 다른 행태로 인해 기존 비자율주행 차량들이 초래하는 고위험 상황의 요인과는 다른 새로운 요인들이 도출될 것으로 보인다. 하지만, 현 시점 국내 에서는 자율주행 차량이 실제로 주행하고 있지 않기 때문에 주행행태를 포함한 데이터 기반의 주요 요인 분석 및 도출에 한계가 있다. 따라서 현 시점에서 자율주행 차량이 혼재하는 환경에서 고위험한 상황을 정의할 수 있는 요인을 도출하기 위해서는 사례 중심의 분석이 필요하다. 따라서 본 연구에서는 기존 국내·외 자율주행차량과 관련된 다양한 논문 사례를 DB화하여 이를 정량적으로 평가할 수 있는 메타 분석(Meta-Analysis) 기법을 통해 향후 자율주행차량이 혼재하는 교통 네트워크에서 안전성을 증진하기 위한 고위험 유발의 주요 요인을 도출하고자 하였다. 본 연구에서 DB화한 논문은 자율주행 차량과 관련된 총 4가지(사고요인, 시나리오, 예측모델, 법규)에 해당 하는 분야로 분류하여 수집하였으며, 2015년부터 2024년 까지 최근 10개년에 해당 되는 사례를 수집하여 분석을 수행하고 주요 요인을 도출하였다. 본 연구의 결과는 향후 자율주행 차량 혼재 시 고위험 상황의 주요 요인들을 바탕으로 각 요인에 기반한 자율주행차량 혼재 시 고위험 상황에 대한 정의를 할 수 있으며, 이러한 고위험 요인들에 의해 도로교통의 안전성이 저해될 수 있는 요인에 대한 사전 예방을 수행할 수 있을 것으로 기대된다.

본 연구는 2017년부터 2021년까지 고속도로에서 발생한 약 9,600건의 사고를 분석하여 자율주행 긴급차량의 신속한 대응 능력을 향 상시키고자 하였다. 조사 결과, 2차 사고가 전체 사망자의 16.8%를 차지하며, 이들 중 약 74%가 선행사고와 관련이 있다는 점이 강조 된다. 이러한 통계는 긴급차량의 신속한 대처 능력이 피해를 최소화하는 데 얼마나 중요한지를 보여준다. 연구에서는 사고의 영향권을 정의하고, 이를 기반으로 긴급차량이 보다 안전하고 효율적으로 사고 현장에 접근할 수 있도록 하는 알고리즘을 개발하였다. 실제 교 통사고 데이터를 활용하여 사고 지속 시간과 다양한 변수를 고려한 기초 분석을 실시하였으며, 도로 특성, 사고 종류, 점유 차로 등 여러 요소를 반영하여 대응 기준을 설정했다. 알고리즘은 자율주행 차량이 실시간으로 주변 정보를 수집하고 신속하게 대응 방안을 마련할 수 있도록 설계되었다. 향후 연구에서는 알고리즘의 실제 도로 환경에서의 적용 가능성을 검토하고, 다양한 변수들을 포함한 추가 연구를 통해 성능을 더욱 개선할 계획이다. 이러한 연구 결과는 교통사고로 인한 피해를 줄이는 데 기여하고, 자율주행 기술을 활용하여 2차 사고의 가능성을 감소시키는 데 중요한 역할을 할 것으로 기대된다.

Recently, due to the expansion of data communication between objects, research related to data communication technology applied to vehicles is being actively conducted. This study selects a network with Wi-Fi 6, which is advantageous in bandwidth, communication speed, and wireless saturation of a wireless network for mobile terminal data communication, and designs and implements Wi-Fi 6 in a vehicle network. In addition, a continuous variable communication structure is proposed to enable high speed data switching in consideration of the characteristics of mobile communication terminal devics, indicating that connection operation and response speed are improved compared to Wi-Fi standard communication methods, and it can be extended to a system for road networks and autonomous driving by expanding it to various event data communication between vehicles.

This study presents a systematic causal analysis of the fuel consumption rate reduction phenomenon observed in mortar-carrier tracked vehicles during driving tests. The investigation focused on identifying the root causes and developing effective improvement measures. Through comprehensive inspections and tests of the chassis and power pack components, along with data analysis, the study identified the damage of the engine flywheel housing gasket and the clogging of the transmission exhaust pump strainer as the main causes of the reduced fuel consumption rate. The causal relationship between the two phenomena was empirically proven using material composition analysis and statistical techniques, enhancing the reliability and validity of the diagnosis. Based on the root cause analysis results, improvements were implemented, including the replacement of the engine gasket and the cleaning of the transmission exhaust pump strainer. The effectiveness of the improvements was quantitatively verified, confirming a significant enhancement in fuel consumption rate and cruising range. By employing a systematic and scientific analysis methodology, this study provides a foundation for improving the reliability and maintenance efficiency of similar weapon systems and power transmission systems in general.

PURPOSES : The purpose of this study is to identify the causes and expected problems of traffic flow in connection with ground roads that are expected to become stagnant owing to the increase in underground road infrastructure, and to derive methods to solve the problem in the future. METHODS : The basic design of underground roads is similar to that of tunnels. However, there is a point where the slope is large as the entering and exiting sections move underground. The ability of a heavy vehicle to assume a mound may vary depending on the slope. Therefore, in this study, a connection path section with a long slope was constructed using VISSIM, a simulation program, and it was verified whether analysis related to the slope and heavy vehicles in an underground road can be performed in the simulation. Subsequently, an analysis was conducted by setting a scenario and an effect index. In particular, this study analyzes internal delay patterns in the event of an unexpected situation on an underground connection road by performing shock wave analysis to analyze speed reduction according to heavy vehicles and slopes. RESULTS : A correlation between the slope of the underground road and decrease in the average speed according to the increasing rate of heavy vehicles was established. It was also possible to analyze the maximum length and duration of the delay connected to the rear in the event of a delay in the underground road and the shock wave speed transmitted to the rear. The analysis showed that the rate of increase in problems owing to delays ranged from 5% to 20% for the ratio of heavy vehicles. In particular, all effect scales increased significantly at a 9% slope. CONCLUSIONS : This study analyzes the causes of land congestion (slope and heavy vehicle mixing rate), which can be a major problem in underground roads in the future. In the future, by establishing lane-specific speed control strategies and lane control strategies based on this study, it will be necessary to derive solutions such as introducing traffic safety on the underground road by minimizing the shock wave delivered to the rear by providing information on traffic communication conditions inside the underground road to individual vehicles.

PURPOSES : This study analyzes the accident damage scale of hazardous material transportation vehicles not monitored in real time by the Hazardous Material Transportation Safety (HMTS) management center. METHODS : To simulate hazardous-material transportation vehicle accidents, a preliminary analysis of transportation vehicle registration status was conducted. Simulation analyses were conducted for hazardous substance and flammable gas transportation vehicles with a high proportion of small- and medium-sized vehicles. To perform a spill accident damage-scale simulation of hazardous-substance transportation vehicles, the fluid analysis software ANSYS Fluent was used. Additionally, to analyze explosion accidents in combustible gas transportation vehicles, the risk assessment software Phast and Aloha were utilized. RESULT : Simulation analysis of hazardous material transportation vehicles revealed varying damage scales based on vehicle capacity. Simulation analysis of spillage accidents showed that the first arrival time at the side gutter was similar for various vehicle capacities. However, the results of the cumulative pollution analysis based on vehicle capacity exhibited some differences. In addition, the simulation analysis of the explosion overpressure and radiant heat intensity of the combustible gas transportation vehicle showed that the difference in the danger radius owing to the difference in vehicle capacity was insignificant. CONCLUSIONS : The simulation analysis of hazardous-material transportation vehicles indicated that accidents involving small- and medium-sized transportation vehicles could result in substantial damage to humans and ecosystems. For safety management of these small and medium-sized hazardous material transportation vehicles, it is expected that damage can be minimized with the help of rapid accident response through real-time vehicle control operated by the existing HMTS management center.

전 세계적으로 실도로에서의 자율주행차 안전성능을 검증하고 자율주행 시스템 기술의 개발을 위해 다양한 실증을 수행하고 있다. 미국의 경우 캘리포니아, 오하이오, 애리조나 등 다양한 주에서 자율주행차의 실도로 테스트를 진행하고 있으며, 독일의 경우 페가수 스 및 이매진 프로젝트 등을 통해 자율주행 성능 및 협력 운행 테스트를 수행하였다. 그러나, 자율주행차의 주행 성능 측면의 평가에 국한되어 실증이 진행되고 있다는 한계가 존재한다. 실도로 환경에서 자율주행차는 비자율주행차, 보행자 및 자전거 등과 상호작용하 며, 다양한 도로 기하구조에서 주행안전성 저하 문제가 발생할 수 있다. 따라서, 본 연구에서는 혼재교통상황에서 자율주행차의 주행 안전성을 저하시키는 도로 기하구조를 도출하였다. 또한, 캘리포니아 Department of Motor Vehicles (DMV)에서 제시한 자율주행차 관련 사고자료 검토를 통해 유사한 도로 기하구조에서 발생할 수 있는 사고 유형을 검토함으로써 선제적인 대안을 마련하고자 한다. 시뮬 레이션 분석을 위한 자율주행차 거동구현의 경우 real-world automated vehicle data (AVD) 기반 주행행태 분석을 통해 VISSIM 파라미 터를 조정하였다. 위험구간 도출을 위해 평가지표를 선정하고 주행안전성 분석을 수행하였으며, 위험 구간의 도로 기하구조의 특성을 도출하였다. 마지막으로 위험구간의 도로 기하구조와 유사한 구간에서 발생한 실제 자율주행차 관련 사고 보고서를 검토함으로써 본 연구에서 도출된 위험구간의 도로 기하구조에서 발생할 수 있는 잠재적 사고 원인을 제시하였다. 본 연구의 결과를 통해 향후 자율주 행차의 실도로 도입을 위해 선제적인 대책을 마려하는데 기초자료로 활용될 수 있으며, 나아가 자율주행차 안전성 향상을 위한 경고 정보 서비스 개발, 정보 제공 인프라 설치 우선순위, 도로 기하구조 개선 사업에 활용할 수 있을 것으로 기대된다.

PURPOSES : Basic research to calculate the appropriate gap acceptance for autonomous vehicles at merging section. Research on whether users prefer short or long gap acceptance. METHODS : Using a driving simulator, experience autonomous driving with different gap acceptance in different weather condition, and analyze which gap acceptance is preferred using survey and biometric data. RESULTS : Regardless of the weather condition, long gap acceptance was preferred, and difference was especially clear in rainy or foggy situation. CONCLUSIONS : It was analyzed that users prefer long gap acceptance over short gap acceptance, and that they feel less frustrated due to long gap acceptance when weather condition is poor.

PURPOSES : This study aims to perform a quantitative analysis of Forward Collision Warning and crash frequency using heavy vehicle driving data collected in expressway driving environments, and to classify the driving environments where Forward Collision Warnings of heavy vehicles occur for accident-prone areas and analyze their occurrence characteristics. METHODS : A bivariate Gaussian mixture model based on inter-vehicle distance gap and speed-acceleration parameters is used to classify the environment in which Forward Collision Warning occurs for heavy vehicles driving on expressways. For this analysis, Probe Vehicle Data of 80 large trucks collected by C-ITS devices of Korea Expressway Corporation from May to June 2022. Combined with accident information from the past five years, a detailed analysis of the classified driving environments is conducted. RESULTS : The results of the clustering analysis categorizes Forward Collision Warning environments into three groups: Group I (highdensity, high-speed), Group II (high-density, low-speed), and Group III (low-density, high-speed). It reveals a positive correlation between Forward Collision Warning frequency and accident rates at these points, with Group I prevailing. Road characteristics at sites with different accident incidences showed that on-ramps and toll gates had high occurrences of both accidents and warnings. Furthermore, acceleration deviation at high-accident sites was significant across all groups, with variable speed deviations noted for each warning group. CONCLUSIONS : The Forward Collision Warning of heavy vehicles on expressways is classified into three types depending on the driving environment, and the results of these environmental classifications can be used as a basis for building a road environment that reduces the risk of crashes for heavy vehicles.

The objective of this study is to analyze the difference between the theoretically calculated torque values of lead screws used in vehicle seat rails and the required torque values due to various disturbances that occur in actual systems. Lead screws were classified into square and trapezoidal threads and modeled by two lead type. Dynamic analysis models were constructed by applying contact conditions and rotational joints between the lead screw and nut. The validity of the dynamic model was verified by comparing the torque values obtained from rigid body dynamic analysis with the theoretically calculated torque values. Then, the lead screw was modeled as a flexible body to investigate the torque variation required for the lead screw when dynamic loads are considered. This study will help predict the actual torque values of lead screws for seat rails.

Recently, halogen lamps for vehicle exterior lamp systems are being replaced by LEDs (Light Emitting Diode) in consideration of miniaturization, power consumption, life, luminance, and eco-friendliness. Due to regulations on the amount of light required, luminance, light uniformity, and glare prevention, it is required to develop a light guide for controlling a light source of an LED lamp for a vehicle. For the development of the light guides, the development of machining technology that can cut micro patterns of hundreds of micrometers scale into surface roughness of tens of nanometers scale must be preceded. In this study, the effect of variations in cutting conditions on surface roughness was analyzed through experiments. The micro patterns was manufactured by cutting into STAVAX material, and the surface of the micro patterns was super-finished using a ball-shaped PCD (polycrystalline diamond) tool without flutes. In experiments, the cutting conditions of the super-finishing process were varied, and the varied cutting conditions were feed rate, radial depth of cut, and spindle speed

In this study, a finite element analysis was used to analyze the stress state and vibration characteristics generated by continuous contact between wheels and rails when driving urban railway vehicles. The rails applied to the analysis were divided into straight and curved shapes, and three-dimensional modeling was performed to analyze the changes in structural characteristics of wheels and rails when driving on straight and curved rails. As a result of the analysis, the stress characteristics were up to 6.5 MPa on a straight rail and 9.81 MPa on a curved rail, and it is believed that this increase in stress will increase noise due to an increase in friction at the interface. The vibration characteristics of the wheels and rails showed similar behavior from the 3rd mode to the 9th mode of the rail to the intrinsic vibration characteristics from the 4th mode to the 6th mode of the wheel.

PURPOSES : The purpose of this study was to investigate the characteristics of concrete pavement behaviors and performance depending on the group-axle types of heavy vehicles, such as single-, tandem-, and tridem-axles. METHODS : The concrete pavement performance indices (such as the rate of fatigue cracking and surface smoothness) according to the different group-axle types of heavy vehicles were predicted using the Korean pavement design program. It was assumed that the load magnitude was the same for each axle, and that the equivalent single-axle traffic volumes were the same for the different group-axle types. The concrete pavement stresses depending on the different group-axle types of heavy vehicles were also analyzed using a finite element analysis program. RESULTS : Based on the design criteria, the concrete pavement performance was the highest under tandem-axle traffic and lowest under single-axle traffic, although the difference in performance was not significant. Based on the structural analysis criteria, the tensile stress of the concrete pavement was the largest under the single-axle load and smallest under the tridem-axle load when the load magnitude of each axle was the same. CONCLUSIONS : Based on the results obtained from considering both the design and analysis criteria, it was concluded that the groupaxle types (such as the tandem- and tridem-axle configurations of heavy vehicles) would not increase the stress or decrease the performance of concrete pavements relative to the single-axle configuration.

PURPOSES : The objective of this study was to evaluate the effectiveness of dust removal by dust removal vehicles by the measuring dust load and PM10 concentrations on the sidewalks of block pavements. METHODS : Field experiments were conducted to determine a dust removal method suitable for the sidewalk conditions, as identified through a literature review. Data collection was followed by the evaluation of the sidewalk dust load with removal vehicles and analysis of the PM10 content within a service road. Moreover, an economic analysis was conducted based on the social costs of dust reduction. RESULTS : When cleaning a sidewalk block by spraying water, the contaminants in small gaps in the block pavement could be reduced, providing a potential solution to void clogging. The dust on the surface of the sidewalk was suspended from a paved road with a high level of traffic volume. Using sidewalk dust removal vehicles with sweeping, spraying water, and inhalation reduced the dust load and PM10 contents by more than 2 and 0.07g/m2, respectively. CONCLUSIONS : According to the economic analysis of the development of dust removal vehicles for sidewalks, the cost-benefit analysis method shows an input effect of 0.4, but if the reduction amount of fine particles such as PM2.5, further experiments are necessary to address the atmospheric fine dust concentrations resulting from cleaning sidewalk block pavements.

본 연구에서는 차량-교량 상호작용 시스템의 고유진동수 변화를 분석하였다. 차량이 주행하는 교량의 동특성은 차량의 질량 및 진 동을 무시하지 않는 경우 상호작용을 반영해야 하는데, 이때 시스템은 시간가변적이므로 고유진동수 또한 시간가변적인 특성을 보인 다. 따라서 본 연구에서는 차량과 교량을 각각 2자유도를 갖는 시스템으로 모델링하여 차량의 위치와 질량비 그리고 시스템 강성비에 따른 시간가변적 고유진동수를 산출하였다. 분석 결과 일반적으로 초기 고유진동수가 작은 시스템은 상호작용으로 인하여 증폭비가 낮아지는 추세를 보이나 상호작용이 발생할 경우 증폭비는 분기점을 보이며 비선형적 추세를 보이는것을 알 수 있다. 따라서 상호작 용이 발생하는 시스템차수에 대한 이해가 필요함을 알 수 있다.