• 한국안전학회지
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• 제25권6호
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• pp.186-196
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• 2010

It has been well known that traffic accidents occur under combined functional contributions of drivers, vehicles and road facilities, and that evaluation of safety levels for a specific road section or point is generally much complicated. Additionally, most of traffic accidents occur randomly implicating it is necessary to be evaluated in terms of probability theory. Thus, the evaluation model which reflects various characteristics and probabilistic distributions of traffic accidents has been necessary. The present paper provides a reliability based model with variables of probabilistic operating speeds and design speeds together which have been individually explaining associated characteristics in traffic accidents. Consequently, the model made it possible for speed management and road improvement projects to be evaluated in a common index. Application studies were performed in three cases. Through the studies, couples of facts were identified that the model successfully considered the probabilistic operating speeds and design speeds together and that then, the model evaluated road safety alternatives relatively which are complicatedly characterized and differently located.

• 응용통계연구
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• 제22권6호
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• pp.1177-1190
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• 2009

도로의 성능을 측정는데 있어서, 주행속도는 가장 중요한 정보가 된다. 또한 도로 교통의 정보를 제공하는데 있어서 현 시점의 교통정보와 더불어 향후 예측되는 교통정보를 함께 제공하는 것은 보다 정확한 예측 시간과 구간을 제공하기 위한 차별화된 기능이라 할 수 있다. 본 연구에서는 그 동안 축적된 도로 구간별 속도 자료를 이용하여 속도 패턴을 다양하게 분석하고 퓨리에 변환 및 삼각함수를 설명변수로 하는 시계열 회귀모형을 이용한 예측모형을 개발하여 구간별 및 시간대별 평균 속도를 예측하였다. 이와 더불어 보다 정확한 예측을 위하여 결측치에 대한 대체 방법 및 특이치 처리 방법을 함께 고려하였고 방대한 데이터에 대한 효율적인 분석을 위하여 유사 속도 구간에 대한 그룹핑(grouping) 방법도 제안하였다.

• 한국도로학회논문집
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• 제15권3호
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• pp.151-157
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• 2013

PURPOSES : This study aims to suggest the optimal spacing between speed humps which is placed at traffic calming areas including pedestrian priority zones, school zones, and residential areas. METHODS: The study measured the operating speed of vehicles passing through two successive humps by using laser gun in 0.2 seconds interval, and analysed the basic statistical characteristics of speeds data to have an insight on the relationship between spacing and speed. Assumption was made to derive the maximum spacing within which two successive humps influence each other. RESULTS: The statistically significant model explaining the relationship between spacing and 85th percentile speed of vehicles was derived as well as the maximum spacing maintained in order to take the benefits of successive installation of humps. CONCLUSIONS: Spacing of 20 meters was suggested to achieve the widely accepted target speed of 30 km/h in traffic calming zone, and spacing of 70 meters was suggested as a maximum spacing. The comparison across the studies were made and empirical reasoning the difference of results between studies was discussed as well as the future studies.

• 한국안전학회지
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• 제32권2호
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• pp.132-146
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• 2017

Appropriate speed limits at a reasonable level in urban roads are highly important factors for efficient and safe movement. Thus, it is greatly necessary to develop the objective models or methodology based on engineering study considering factors such as traffic accident rates, roadside development levels, and roadway geometry characteristics etc. The purpose of this study is to develop the estimate model of appropriate speed limits at each road sections in urban roads using traffic information big data and field specific data and to review the effects of accident decrease. In this study, the estimate method of appropriate speed limits in directional two or more lanes of urban roads is reflecting features of actual variables in a form of adjustment factor on the basis of the maximum statutory speed limits. As a result of investigating and testing influential variables, the main variables to affect the operating speed are the function of road, the existence of median, the width of lane, the number of traffic entrance/exit path and the number of traffic signal or nonsignal at intersection and crosswalk. As a result of testing this model, when the differences are bigger between the real operating speed and the recommended speed limits using model developed in this study, the accident rate generally turns out to be higher. In case of using the model proposed in this study, it means accident rate can be lower. When the result of this study is applied, the speed limits of directional two or more lane roads in Seoul appears about 11km/h lower than the current speed limits. The decrease of average operating speed caused by the decrease of speed limits is 2.8km/h, and the decrease effect of whole accidents according to the decrease of speed is 18% at research road. In case that accident severity is considered, the accident decrease effects are expected to 17~24% in fatalities, 11~17% in seriously injured road user, 6~9% in slightly injured road user, 5~6% in property damage only accidents.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1175_1176
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• 2009

In comparison with different mass transportation systems, the streetcar is lower, both in speed and transportation capacity. However, it has the advantage of reducing the cost of construction, because it makes infrastructure simple, by using the road. It is proper in the city, where the population is few, to raise the efficiency of traffic. The convenience is high to passengers. On time accuracy and the commercial speed is influenced by operating condition. Generally that is organized into 21m degree in 6 quantity. All passengers in a streetcar are about 180 people. The maximum speed is 40~60km/h. When road traffic is considered, the speed can be reduced to 15km/h. To enhance the speed, the construction of a priority signaling system is necessary which is integrated with the road traffic operation information system. In order to develop a better Traffic Control System which is connected to a Traffic Control Center, a Priority Signaling System which incorporates Intersection Control Technics must be included.

• 대한토목학회논문집
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• 제30권2D호
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• pp.105-111
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• 2010

주행속도는 고속도로 설계와 운영에 있어 주요한 요소 중 하나이다. 거시적으로 자유교통류 속도(FFS)를 분석한 몇 몇 연구가 보고되고 있으나, 표본수가 적고 교통량과 일중 시간대의 영향을 고려하지 않았다. 본 연구는 FFS의 특성을 분석하기 위해 방대한 양의 표본을 이용하여 자유교통류 상태에서 교통량 수준별 일중 시간대별에 따른 FFS의 분포와 Percentile속도를 미시적으로 분석하였다. 분석결과, 속도분포는 교통량(1-5대/30초)과 일중 시간대(0-5, 6-8, 9-11, 12-19, 20-23)에 따라 변화하였으며 다른 행태를 보였다. 아침, 저녁, 심야 시간대의 V85(85th Percentile 속도)는 교통량이 증가함에 따라 감소하였지만, 오전과 오후 시간대의 V85는 큰 변화를 보이지 않았다. 따라서 시간대에 따른 V85는 교통량이 증가함에 따라 급격하게 변화하였다.

• Asia pacific journal of information systems
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• 제26권3호
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• pp.427-448
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• 2016

The stochastic phenomena of traffic network condition, such as traffic speed and density, are affected not only by exogenous traffic control but also by endogenous changes in service time during congestion. In this paper, we propose a mixed M/G/1 queuing model by introducing a condition-varying parameter of traffic congestion to reflect structural changes in the traffic network. We also develop congestion indices to evaluate network efficiency in terms of traffic flow and economic cost in traffic operating system using structure-changing queuing model, and perform scenario analysis according to various traffic network improvement policies. Empirical analysis using Korean highway traffic operating system shows that our suggested model better captures structural changes in the traffic queue. The scenario analysis also shows that occasional reversible lane operation during peak times can be more efficient and feasible than regular lane extension in Korea.

• 한국ITS학회 논문지
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• 제23권2호
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• pp.32-49
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• 2024

본 논문에서는 도로교통 여건과 제한속도 변화가 교통소통과 안전에 미치는 영향을 분석하였다. 교통소통지표로 통행속도와 순행속도, 「순행속도-통행속도」, 편차, 대편차비율, 상충횟수 등을 안전지표로 설정하고 도로교통 여건과 제한속도 변화가 이들에 미치는 영향을 분석하였다. 분석 결과에 의하면 제한속도는 소통지표에는 크게 영향을 주지만 안전지표에는 크게 영향을 주지 않는 것으로 분석되었다. 통계적 유의성 검정 결과 제한속도가 증가함에 따라 소통지표는 증가한다는 것이 유의하다고 입증되었다. 그러나 안전지표들은 증가하는 경우가 많지만 통계적으로는 유의성이 입증되지 않았다. 그러므로 다양한 도로여건과 교통량 변화에 따른 교통흐름 상태를 현실적으로 고려해서 제한속도가 설정되고 운영된다면 운전자들이 주행하는 속도에 부합되고 교통소통과 안전이 향상된다고 할 수 있다. 따라서 본 논문에서 제시한 교통소통지표와 안전지표들을 고려하여 제한속도를 산정하고 교통량 변화에 따라 제한속도를 운영할 경우 도로상의 교통 흐름을 안정화시키는 데 기여할 것으로 기대된다.

• 한국ITS학회 논문지
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• 제21권5호
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• pp.149-161
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• 2022

제한속도는 주행속도에 영향을 주기 때문에 교통흐름은 물론 교통사고와도 밀접한 관계에 있다. 기존 제한속도 산정 방법은 공학적 판단요소로 차로수, 교차로 간격, 진출입로 수, 횡단보도 수, 85백분위 속도, 토지이용 형태, 도로기하 특성 등 다양한 요소들을 고려하지만 대부분이 교통시설에 해당되고 교통량을 고려한 교통영향분석이 이루어지지 않고 있어 공학적 분석이 미흡하다고 할 수 있다. 또한 지점속도인 85%속도만으로는 도로 전체의 교통류 특성을 잘 반영해주지 못한다. 따라서 본 논문에서는 교차로 간격과 교통량 조건에서 제한속도 변화가 순행속도와 통행속도의 크기와 그 차이에 미치는 영향을 상세하게 분석하였다. 그리고 그 결과를 활용하여 제한속도 변경 전과 동일한 서비스수준을 유지토록 하여 속도개선효과를 높이고 순행속도와 통행속도의 차이를 줄이는 제한속도 산정방안을 제안하였다. 그리고 교통량 변화에 따른 가변적 제한속도 운영방안도 제시하였다. 본 방안은 속도개선효과를 확보하면서 교통사고 심각도에 영향을 주는 속도 차이를 줄이고 교통량 변화에 따른 주행속도 변화를 반영한 제한속도 운영으로 운전자들의 제한속도 준수율을 높여 안전측면에서도 효과가 기대된다.

• 한국분무공학회지
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• 제21권4호
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• pp.214-222
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• 2016

Changes in road infrastructure affect driving patterns and pollutant emission characteristics. we analyzed the changes in driving patterns and pollutant emission characteristics of the driving route via measured driving patterns at year 2009 and 2016. Since 2009, there has been an increase in population and traffic demand, including residential areas and industrial facilities. Traffic conditions were improved such as the opening of the highway Inter-Change to Seoul and the construction of underground driveway. As a result, the average vehicle speed increased. More detail comparisons have made on the changes of the underground driveway section and the crossroad section, which are expected to have significant changes in the transportation infrastructure. The vehicle speed distribution of the underground driveway changed from low speed to high speed, and the increase of the time spent at the high speed and high load caused the increase of NOx emissions. The vehicle speed also increased at the crossroad section, and the consequence NOx and $CO_2$ emissions decreased. It is mainly because the decreased time spent at idle, which results from the proper traffic demand management at this area.