PURPOSES : This study aimed to investigate the factors affecting the severity of traffic crashes caused by personal mobility (PM) devices compared with those involving victims. METHODS : Traffic crashes involving PM devices were used to build a non-parametric statistical model using a classification tree. Based on the results, the factors influencing both at-fault and victim-related crashes caused by PM devices were analyzed. The factors affecting accident severity were also compared. RESULTS : Common factors affecting the severity of traffic crashes involving both perpetrators and victims using PM devices include occurrences at intersections, crosswalks at intersections, single roads, and inside tunnels. Traffic law violations by PM device users (perpetrators) influence the severity of crashes. Meanwhile, factors such as the behavior of perpetrators using other modes of transportation, rear-end collisions, road geometry, and weather conditions affect the severity of crashes where PM device users are the victims. CONCLUSIONS : To reduce the severity of traffic crashes involving PM devices, it is essential to extend the length of physically separated shared paths for cyclists and pedestrians, actively enforce laws to prevent violations by PM device users, and provide systematic and regular educational programs to ensure safe driving practices among PM device users.

PURPOSES : According to government data, the Black Spot Program has resulted in an average 28.8% reduction in traffic accidents within one year of project implementation in areas where road conditions improved. However, there has been a lack of in-depth analysis of the midto- long-term effects, with a predominant focus on short-term results. This study aimed to analyze the mid-to-long-term effects of the Black Spot Program to assess the sustainability of its reported short-term impact. Additionally, the differences in the mid-to-long-term effects were investigated based on the scale of traffic accidents at intersections and the characteristics of these effects are revealed. METHODS : The mid-to-long-term effects of the Black Spot Program were analyzed at 122 intersections in Seoul, Korea, where the program was implemented between 2013 and 2017, using traffic accident data spanning five years before and after implementation. Additionally, the differences in the program's effects were analyzed at the top-100 intersections with the highest traffic accident concentration in Seoul using the chi-square test to identify these differences. To theoretically validate these differences, the Hurst exponent, commonly used in economics, was applied to analyze the regression to the mean of the intersections and reveal the correlation with improvement. RESULTS : Through the Black Spot Program at 122 intersections, a 33.3% short-term accident reduction was observed. However, the midto- long-term effect analysis showed a 25.8% reduction, indicating a slightly smaller effect than previously reported. Specifically, the top-100 intersections exhibit a 15.4% reduction. A chi-square test with a 95% confidence level indicated significant differences in the program’s effects based on the scale of traffic accidents at intersections. The Hurst index (H ) was measured for the top-100 intersections, yielding H = 0.331. This is stronger than the overall H = 0.382 for all intersections in Seoul, suggesting that the regression to the mean is more pronounced, which may lead to a lower effectiveness of the improvement. CONCLUSIONS : The mid-to-long-term effects of the Black Spot Program were relatively lower than its short-term effects, with larger differences in effectiveness observed based on the scale of traffic accidents at intersections. This indicates the need to redefine the criteria for selecting project targets by focusing on intensive improvements at intersections, where significant effects can be achieved.

PURPOSES : This study aimed to derive the factors that contribute to crash severity in mixed traffic situations and suggest policy implications for enhancing traffic safety related to these contributing factors. METHODS : California autonomous vehicle (AV) accident reports and Google Maps based on accident location were used to identify potential accident severity-contributing factors. A decision tree analysis was adopted to derive the crash severity analyses. The 24 candidate variables that affected crash severity were used as the decision tree input variables, with the output being the crash severity categorized as high, medium, and low. RESULTS : The crash severity contributing factor results showed that the number of lanes, speed limit, bus stop, AV traveling straight, AV turning left, rightmost dedicated lane, and nighttime conditions are variables that affect crash severity. In particular, the speed limit was found to be a factor that caused serious crashes, suggesting that the AV driving speed is closely related to crash severity. Therefore, a speed management strategy for mixed traffic situations is proposed to decrease crash severity and enhance traffic safety. CONCLUSIONS : This paper presents policy implications for reducing accidents caused by autonomous and manual vehicle interactions in terms of engineering, education, enforcement, and governance. The findings of this study are expected to serve as a basis for preparing preventive measures against AV-related accidents.

2011년 발생한 동일본대지진의 영향으로 후쿠시마 원자력발전소 폭파사고 이후 국제원자력기구(IAEA)의 방사선비상계획구역(EPZ) 확 대를 권고하였으며, 이에 따라 우리나라에서도 방사선비상계획구역(EPZ, Emergency Planning Zone)를 기존 반경 8~10km에서 20~30km 로 확대를 하였다. 이에 따라 방사선 비상시 대규모 대피에 관한 관심이 높아지며 원활한 대피를 위한 교통운영관리전략 수립이 필요 한 실정이다. 방사선 비상과 같은 대규모 재난이 발생하면 동시다발적인 대피수요가 발생하고 한정된 도로교통망에 차량이 집중되어 극심한 혼잡이 발생할 것으로 예상된다. 따라서, 본 연구에서는 교통분야에서 활용되는 도로운영관리전략 중 방사선비상시 적용 가능 한 전략 및 적용기준을 수립한다. 또한, 선정된 도로운영관리전략의 효과분석을 위하여 TOVA를 활용하였으며, Sub Network 기능으로 대상지역의 네트워크를 추출 후 분석을 시행하였다. 방사선비상시 도로운영관리전략은 도로용량 증대, 통행속도 향상, 교통수요 관리 및 기타 등 네 가지로 구분하여 분류하였다. 이 중 우리나라에 도입되지 않은 역류차로제 전략 도입 효과분석을 수행하였다. 시뮬레이 션 대상지는 고리원자력 발전소의 사고가 발생한 것으로 가정하며, 대피인원은 원자력발전소에서 부산광역시로 이동하는 것으로 설정 하였다. 효과분석 결과, 시행시 120.6%의 교통량(시간당 7,600대)과 117% 속도(30.21km/h → 65.55km/h)가 증가되는 것으로 분석되었다

2020년 국토교통부에서는 ‘결빙 취약구간 평가 세부 배점표’에 의하면, 전국의 고속국도 및 일반국도를 대상으로 결빙 취약 구간 464 개소를 선정하여 관리중에 있다. 그러나 감사원은 2020년 진행한 주요 사회기반시설(도로ㆍ고속철도) 안전관리실태 감사에서 결빙 취 약 구간 선정 시 터널 입출구부 등 결빙위험이 큰 구간이 도로포장 홈파기 대상구간에서 누락된 점을 지적하였다. 이러한 근거로 결 빙에 취약한 터널 입ㆍ출구에서 결빙사고가 우려되는 등 ‘겨울철 도로교통 안전 강화대책’의 실효성이 저하될 가능성이 제시되었다. 또한 본 연구에서 자체적으로 검토한 결과, 4개 특성 12개 항목으로 구성된 ‘결빙 취약구간 평가 세부 배점표’의 도로시설 항목에서 터널, 교량 등 도로시설물의 배점 부여 기준을 확인하기 어려웠으며, 각 도로시설에 대한 정의가 모호하여 평가표의 현장 적용성이 제 한되거나 신뢰도 검증이 부족한 점을 확인하였다. 본 연구에서는 국토교통부에서 제공하는 노드(Node) 및 링크(Link) 기반의 국내 도로망 GIS(Geographic Information System)데이터 에 결빙사고 데이터의 위치정보를 결합하여 고속국도 및 일반국도의 터널 및 교량 등을 포함하는 도로시설물 및 그 주변에서 발생한 결빙사고 이력을 자료화하였다. 최종적으로 도로시설물별 결빙사고 발생 비율 및 사고 심각도(사망자, 부상자 수)에 대한 분석을 통해 도로시설물의 결빙사고 상관 정도와 영향 범위를 파악하였다.

고속도로 터널 구간은 일반 도로에 비해 사고 발생 빈도와 심각도가 높으며, 특히 터널 내에서 발생하는 사고나 공사와 같은 돌발 상황은 대기 행렬을 유발해 후미 추돌 위험을 증가시킨다. 본 연구에서는 운전자가 돌발 상황 지점에 접근할 때 선제적으로 대응할 수 있도록, Driving Simulator를 활용하여 다양한 정보를 제공하는 터널 내 교통관리 시스템의 효과를 분석하였다. 분석 대상은 차로 변 경 유도, 속도 감소 유도, 돌발 상황 안내로 구성된 세 가지 교통관리 시스템의 개별 효과와 이들의 통합 운영이 터널의 안전성과 운 영 효율성에 미치는 영향을 포함하였다. 분석 결과, 세 가지 교통관리 시스템을 통해 터널 내 평균 통행 속도가 증가하였으며, 돌발 상황 발생 지점에서 차량의 차로 변경과 감속이 선제적으로 이루어지고 급감속 횟수가 현저히 감소하였다. 본 연구는 터널 내 돌발 상황 발생 시 다양한 정보를 제공함으로써 터널의 안전성과 교통흐름을 개선할 수 있음을 입증하였으며, 특히 여러 시스템을 통합적 으로 운영할 때 그 효과가 극대화됨을 Surrogate Safety Measure를 통해 확인하였다. 이러한 결과는 향후 터널 교통관리에서 단일 시스 템의 기능만을 고려하기보다는, 다양한 교통관리 시스템 간 상호작용을 고려해야 함을 시사한다.

세계의 많은 도시들은 하천과 항구와 함께 발전해 왔으며, 고대부터 현대까지 교통과 물류의 주요한 축으로 기능하였다. 본 연구는 한강이 가로지르는 서울을 포함하여, 세계 여러 도시에서 현재 운영되고 있는 수상교통 시스템을 조사하였고, 이를 바탕으로 설문조사 를 통해 데이터를 수집, 다항 로지스틱 회귀분석을 통해 수상교통에 대한 사람들의 인식에 영향을 미치는 요인을 알아보았다. 연구의 목적은 수상교통의 특성, 이용자의 개인적 성향 등을 고려하여 수상교통의 이용 의향 여부와 통근형과 관광형 수상교통에 대한 선호 도를 분석하는 것이다. 서울에 거주하고 근무하는 150명의 직장인을 대상으로 온라인 설문조사를 실시하였으며, 세계 각국의 도시 수 상교통에 대한 사전 조사를 통해 공통적 특성을 파악하였다. 설문조사는 인구통계학적 특성, 직업 관련 요인, 도시 수상교통에 대한 인식, 교통수단 특성의 중요성, 개인 성향 등을 조사할 수 있도록 구성하였다. 분석은 빈도분석, 요인분석, 신뢰도 분석을 거쳐 다항 로지스틱 회귀분석을 통해 각 요인의 영향을 정량적으로 파악하였다. 분석 결과, 수상교통의 이용 의향 여부에 유의미한 영향을 미치 는 요인에는 연령, 출근 시간, 출근 시 주 교통수단, 그리고 개인 성향 중 이동 시 넓은 시야를 확보하고 풍경을 관람하는 것을 선호 하는 성향, 새로운 것을 시도하는 것을 좋아하는 성향이 있는 것으로 분석되었다. 통근형과 관광형 간의 선호도에 유의미한 영향을 미 치는 요인으로는 출근 시간과, 개인 성향 중 교통수단의 안전성에 대한 민감도, 여행 중 야외 활동에 대한 선호도가 있는 것으로 분석 되었다. 본 연구는 도시 수상교통에 대한 이용자 특성과 선호도 간의 관계를 파악하여 향후 수상 공간의 교통수단 계획에 기여할 수 있는 통찰을 제공한다.

PURPOSES : This study empirically examines the determinants of traffic accidents by focusing on the transport culture index. METHODS : Two-stage least-squares estimation using an instrumental variable is used as the identification strategy. As the instrumental variable of the transport culture index, its past values, particularly before the outbreak of COVID-19 in 2018 are used. RESULTS : The empirical results, considering the potential endogeneity of the transport culture index, show that areas with higher values of the index are likely to have fewer traffic accident casualties. Local governments of regions with relatively frequent traffic accidents can run campaigns for residents to fasten their seatbelts, causing reverse causation. Ignoring this type of endogeneity underestimates the importance of the index as a key determinant of traffic accidents. CONCLUSIONS : Several traffic accidents occur in Korea, e.g., 203,130 accidents with 291,608 injuries and 5,392 deaths. As traffic accidents cause social costs, such as delays in traffic flow and damage to traffic facilities, public interventions are required to reduce them. However, the first step in public intervention is to accurately understand the relationship between the degree of damage in traffic accidents and the transport-related attributes of the areas where the accidents occurred. Although the transport culture index appears to be an appropriate indicator for predicting local traffic accidents, its limitations as a comprehensive index need to be addressed in the future.

PURPOSES : Even when autonomous vehicles are commercialized, a situation in which autonomous vehicles and regular drivers are mixed will persist for a considerable period of time until the percentage of autonomous vehicles on the road reaches 100%. To prepare for various situations that may occur in mixed traffic, this study aimed to understand the changes in traffic flow according to the percentage of autonomous vehicles in unsignalized intersections. METHODS : We collected road information and constructed a network using the VISSIM traffic simulation program. We then configured various scenarios according to the percentage of autonomous vehicles and traffic volume to understand the changes in the traffic flow in the mixed traffic by scenario. RESULTS : The results of the analysis showed that in all scenarios, the traffic flow on major roads changed negatively with the mix of autonomous vehicles; however, the increase or decrease was small. By contrast, the traffic flow on minor roads changed positively with a mix of autonomous vehicles. CONCLUSIONS : This study is significant because it proactively examines and designs traffic flow changes in congested traffic that may occur when autonomous vehicles are introduced.

자율주행에 관한 관심은 전 세계적으로 증가하고 있으며, 글로벌 자동차 제조사들과 기술기업들이 자율주행 분야에 대한 투자를 늘 리고 있어 향후 자동차 산업과 교통체계 전반에 큰 변화가 전망된다. 이처럼 자율주행 관련 연구와 개발은 끊임없이 진보하고 있으며, 관련 연구 수행은 계속해서 이루어질 것으로 보인다. 연구 수행에 있어 동향 파악은 필수 요소이며, 본 연구에서는 국내 자율주행 연 구 동향을 분석하고자 한다. 연구 동향을 분석한 다양한 분야의 선행연구 검토 결과, 각각 연구 목적에 맞는 다양한 데이터베이스를 이용하여 데이터를 수집하였으며 연구 주제어 혹은 초록을 분석데이터로 활용하였음을 확인하였다. 자율주행 연구 동향에 대해 분석 한 선행연구 검토 결과, 기존 연구들은 분야를 구분하지 않고 연구를 수집·분석하였음을 확인하였다. 자율주행은 도로, 교통, 자동차, 기계, 컴퓨터, 전자, 전기 등 다양한 분야를 포함하고 있기에 분야별 연구 동향 분석이 필요하다. 이에 본 연구에서는 도로·교통 분야 의 동향 분석을 위해 최근 5년간(2019년~2023년) 국내 도로·교통 분야 등재 학술지에 게재된 학술 논문을 대상으로 연구 동향을 분석 하였으며, 보다 많은 텍스트 데이터를 활용하기 위해 주제어가 아닌 초록을 활용하였다. 키워드 출현 빈도 분석을 통해 주요 키워드를 도출하였으며, 토픽 모델링을 통해 주요 연구주제를 도출하였다. 본 연구에서 수행한 자율주행 연구 동향 파악은 도로·교통 분야에서 향후 수행될 자율주행 연구 방향 수립에 시사점을 제공할 것이라 기대된다.

국토교통부는 2020년 '결빙 취약구간 평가 세부 배점표’에 따라, 전국의 고속국도와 일반국도를 대상으로 410개 구간의 결빙 취약구 간을 선정하였다. 그러나, 2021년 감사원의 결빙 취약구간 지정 적정성 감사 결과에서 감사원은 현재 지정ㆍ관리 중인 결빙 취약구간 및 결빙 취약구간 평가 세부 배점표의 적정성에 문제를 제기하였다. 이에, 국토교통부는 결빙 취약구간을 재지정하여 발표하였으나 그 에 대한 평가 및 지정 적정성 검증이 아직 이루어지지 않았다. 본 연구에서는 결빙 취약구간과 결빙사고 데이터의 위치정보를 수집하여 GIS(Geographic Information System) 데이터로 구축하고 맵핑(Mapping)하여 결빙 취약구간 내 결빙사고이력을 확인함으로서 결빙 취약구간의 결빙사고 예측성능을 평가하였다. 또한, 각 결빙 사고 발생지점에서 도로시설, 교통, 선형구조, 환경인자 데이터를 수집하여 분석한다. 이를 통해 결빙사고와 각 인자 간의 상관성을 파 악하고, 그 결과에 따라 결빙 취약구간 평가 세부 배점표의 평가항목 및 각 항목별 배점을 수정하고 보완함으로써 결빙 취약구간의 신뢰성을 제고한다.

겨울철 국내 도로 결빙으로 인한 교통사고가 증가하는 추세를 보이고 있으며 2018년~2022년까지 총 4,609건의 결빙 교통사고가 발 생하였다. 결빙 교통사고의 치사율은 2.3으로 일반적인 교통사고와 비교하여 높은 치사율을 보이며 최근 5년(2018~2022)동안 결빙 교 통사고로 인하여 107명이 사망자와 7,728명의 부상자가 발생하였다. 현재 국토교통부에서 제시한 결빙 취약구간 평가기준표에 따라 결 빙 위험 구간을 지정하고 있으나, 해당 기준은 결빙의 주요 요인으로 고려되는 기상조건을 충분히 반영하지 못하고 있다. 도로 결빙은 노면온도가 0℃ 이하이며 노면에 수분이 공급될 때 형성되며 기온, 구름량, 풍속, 풍향, 상대습도, 강수량 등의 기상인자들이 복합적으 로 작용하여 결빙이 발생한다는 점을 고려하였을 때, 기상 특성은 도로 결빙의 주요 인자로 판단된다. 따라서 국내 결빙 취약구간 평 가기준의 개선이 필요하며 본 연구의 목적은 국내 결빙 교통사고 데이터를 분석하고 결빙이 형성되는 기상 조건을 구체화하는 것이다. 분석을 위한 데이터로 2018년~2022년까지 5년동안 발생한 결빙사고 사례와 기상청 방재기상관측소(AWS)에서 제공하는 기상 데이터 를 적용하였다. 이후, 박스도표, 확률밀도함수 등의 통계분석을 적용하여 결빙 형성 기상 조건을 구체화하였다. 이를 통하여 기존 결빙 취약구간 평가기준의 기상학적 개선 방향성을 제시할 수 있으며 더 나아가 도로 결빙 예측 로직 개발을 기대할 수 있다.

PURPOSES : This study aimed to identify factors affecting the duration of traffic incidents in tunnel sections, as accidents in tunnels tend to cause more congestion than those on main roads. Survival analysis and a Cox proportional hazards model were used to analyze the determinants of incident clearance times. METHODS : Tunnel traffic accidents were categorized into tunnel access sections versus inner tunnel sections according to the point of occurrence. The factors affecting duration were compared between main road and tunnel locations. The Cox model was applied to quantify the effects of various factors on incident duration time by location. RESULTS : Key factors influencing mainline incident duration included collision type, driver behavior and gender, number of vehicles involved, number of accidents, and post-collision vehicle status. In tunnels, the primary factors identified were collision type, driver behavior, single vs multi-vehicle involvement, and vehicles stopping in the tunnel after collisions. Incidents lasted longest when vehicles stopped at tunnel entrances and exits. In addition, we hypothesize that incident duration in tunnels is longer than in main roads due to the reduced space for vehicle handling. CONCLUSIONS : These results can inform the development of future incident management strategies and congestion mitigation for tunnels and underpasses. The Cox model provided new insights into the determinants of incident duration times in constrained tunnel environments compared to open main roads.

PURPOSES : This study aimed to improve the effect of increasing the number of urban railway users when public transportation accessibility is improved by using village buses. METHODS : Using the case of Daejeon City, this study utilized the greenhouse gas reduction benefit among the benefits of the investment evaluation guidelines of the Ministry of Land, Infrastructure and Transport to demonstrate the effect of introducing village buses, a flexible means of transportation, to transportation-disadvantaged areas and improving accessibility, thereby inducing a change to urban railways. and were quantitatively analyzed. RESULTS : The number of users expected to switch to urban rail was 9,964 in 2020 and 9,220 in 2025. Thus, the greenhouse gas reduction effect is predicted to decrease annually by 34,554 t (2020) and 31,973 t (2025). CONCLUSIONS : Among the demand management techniques, reducing the use rate of passenger cars is one of the most important. For this policy, it is most effective to provide an alternative means of transportation.

PURPOSES : This study is to analyze the reduction effect on road pavement damage from the installation of weigh-in-motion systems used for overloaded vehicle enforcement, from the perspective of traffic assignment. METHODS : Fixed-demand multi-class traffic assignment was conducted by VISUM, a macroscopic traffic simulation software. We considered three vehicle classes and calculated the traffic load for each road link using the ESAL(Equivalent Single Wheel Load) factor, as proposed by ASHTTO(American Association of State Highway and Transportation Officials). We set up scenarios with weigh-in-motion installations in certain sections and observed how the traffic load changed before and after the installation of weigh-in-motion for each scenario. RESULTS : Three main trends were observed. Firstly, at points where weigh-in-motion systems were installed, traffic load significantly decreased even with the influx of cars and trucks following the restriction of overloaded trucks, highlighting the significant influence of overweight vehicles on the traffic load. Secondly, even when overweight vehicles detoured, there was no significant change in the overall network's traffic load. Lastly, the detour of overweight vehicles led to an increase in the total driving distance and time for all vehicles. CONCLUSIONS : Installing weigh-in-motion systems in sections with a lower structure number, which indicates thinner road pavement, can prevent damage in those specific areas without affecting the entire road network.

This study analyzes the seismic response of traffic light poles, considering soil-foundation effects through nonlinear static and time history analyses. Two poles are investigated, uni-directional and bi-directional, each with 9 m mast arms. Finite element models incorporate the poles, soil, and concrete foundations for analysis. Results show that the initial stiffness of the traffic light poles decreases by approximately 38% due to soil effects, and the drift ratio at which their nonlinear behavior occurs is 77% of scenarios without considering soil effects. The maximum acceleration response increases by about 82% for uni-directional poles and 73% for bi-directional poles, while displacement response increases by approximately 10% for uni-directional and 16% for bi-directional poles when considering soil-foundation effects. Additionally, increasing ground motion intensity reduces soil restraints, making significant rotational displacement the dominant response mechanism over flexural displacement for the traffic light poles. These findings underscore the importance of considering soil-foundation interactions in analyzing the seismic behavior of traffic light poles and provide valuable insights to enhance their seismic resilience and safety.

PURPOSES : This study aims to analyze the causes of pedestrian traffic accidents on community roads. METHODS : This study collected variables affecting pedestrian traffic accidents on community roads based on field surveys and analyzed them using negative binomial regression and zero-inflated negative binomial regression models. RESULTS : Model analysis results showed that the negative binomial regression model is more suitable than the zero-inflation negative binomial regression model. Additionally, the segment length (m), pedestrian volume (persons/15 min), traffic volume (numbers/15 min.), the extent of illegal parking, pedestrian-vehicle conflict ratio, and one-way traffic (one: residential, two: commercial) were found to influence pedestrian traffic accidents on community roads. Model fitness indicators, comparing actual values with predicted values, showed an MPB of 1.54, MAD of 2.57, and RMSE of 7.03. CONCLUSIONS : This study quantified the factors contributing to pedestrian traffic accidents on community roads by considering both static and dynamic elements. Instead of uniformly implementing measures, such as pedestrian priority zones and facility improvements on community roads, developing diverse strategies that consider various dynamic factors should be considered.

PURPOSES : Traffic volume, an important basic data in the field of road traffic, is collected from traffic survey equipment installed at certain locations, which sometimes results in missing traffic volume data and abnormal detection. Therefore, this study presents various missing correction techniques using traffic characteristic analysis to obtain accurate traffic volume statistics. METHODS : The fundamental premise behind the development of a traffic volume correction and prediction model is to set the corrected data as the reference value, and the traffic volume correction and prediction process for the outliers and missing values in the raw data were performed based on the set values. RESULTS : The simulation results confirmed that the algorithm combining seasonal composition, quantile AD, and aggregation techniques showed a detection performance of more than 91% compared with actual values. CONCLUSIONS : Raw data collected due to difficulties faced by traffic survey equipment will result in missing traffic volume data and abnormal detection. If these abnormal data are used without appropriate corrections, it is difficult to accurately predict traffic demand. Therefore, it is necessary to improve the accuracy of demand prediction through characteristic analysis and the correction of missing data or outliers in the traffic data.

PURPOSES : This study aims to examine actual cases of providing detour information in accidental situations such as traffic accidents and road construction through a VMS installed on national highways in metropolitan areas with alternative routes, as well as cases of simultaneously providing travel time information on parallel paths such as national and regular highways. For each case, we analyzed whether the provision of VMS traffic information leads to route changes and substantial effects. METHODS : To analyze traffic changes on the main and detour roads based on the detour information provided on traffic accidents in actual cases, the traffic volume and speed on the accident day were compared with those on the same days and at the same time of the day (regular days) based on the VDS data of the main and detour roads. Cases providing more detour information on road construction were investigated by examining three time periods: one week from construction initiation and one week before and after the construction period (regular days). The traffic volume and speed on the main road were compared based on the VDS data, and those on the detour road were compared based on data made available by private entities. Regarding the cases of simultaneously providing drivers with comparative information on travel time over parallel sections of national and regular highways, traffic situation changes in highways were analyzed in the following special traffic control periods (New Year's Day, NY Day), during which congestion is expected due to heavy traffic: before and after the provision of comparative information for 2015 New Year's Day and 2016 NY Day. RESULTS : The detour rate related to route changes based on the detour information for traffic accidents was 35%. On the detour route, the traffic volume increases as traffic from the main road is absorbed. However, the average travel speeds did not differ significantly. When further detour information regarding a road construction project was provided, the detour rate from the main road was 21%. The travel speeds were similar, except on the first day of construction. Almost no changes were observed in the first section of the detour. The speed slightly decreased in the second section but did not significantly hinder the traffic flow. When comparative traffic time information on parallel routes (national highways and expressways) was provided, the traffic volume increased to some extent after the report was provided for every case. However, the data frequency rate in the 5-min unit, which was still under the congestion speed standard (40 km/h), decreased. This indicates that traffic congestion was significantly relieved. CONCLUSIONS : Previous studies on detour rates or route changes based on VMS traffic information have focused on VMS instruments on expressways. Although their estimates were based on simulated situations, this study used actual VMS installed on national highways. In addition, this study utilizes the existing case records of national highway ITS centers, covering traffic situation monitoring, measures for accidental situations, etc., in regular times or special traffic control periods, as well as statistical data, including ITS real-time traffic information. The analysis results of this study accurately represent situations on actual roads and can be utilized to analyze future ITS operation and installation project effects.