• 한국항만학회지
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• 제13권1호
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• pp.113-122
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• 1999

Congestion and traffic accidents occur on the merge and diverge sections in the interchange of the freeway. Studies have been conducted to reduce the traffic delay and accidents on the merge section in the freeway since 1960s. but a study was not conducted to estimate the speed variation on the merge section construct models estimated for the speed variation and suggest the appropriate measures. The purpose of this study was to identify the traffic flow characteristics on the merge section in the freeway construct the models estimated for the speed variation on the merge section in the freeway and finally establish the appropriate measure for reduction of traffic delay and accidents on the merge section in the freeway. The following results were obtained: I) Speed variations in the urban freeway appeared to be about 3.2mph, 6.5mph and 7.4mph based on the morning peak period, afternoon peak period and 24-hours period but those in the suburban freeway appeared to be about 8.0mph, 11.1mph and 10.1mph based on the same periods respectively. So different speed reduction signs need be installed to reduce delay and accidents on the merge section in the freeway based on the areas and periods as the freeway traffic management system(FTMS). ii) These models estimated for speed variation need to be studied with the changeable message sign(CMS) technique based on the real-time data so that the traffic flow could be maximized and the traffic delay and accidents be on the merge section in the freeway as more efficient freeway traffic management system(FTMS) in the near future.

• 한국도로학회논문집
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• 제18권4호
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• pp.77-82
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• 2016

PURPOSES : This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

• 한국항만학회지
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• 제13권2호
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• pp.333-350
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• 1999

Today freeway is thought to be a very important transportation facility carrying tremendous traffic flow as the main corridor within the area of between the areas. However freeway is experiencing severe congestion and accidents by increased entrance ramp flow especially at peak time period. Ramp meters on the freeway entrance ramps that supply traffic to the freeway in a measured or appropriately regulated amount are needed for alleviating freeway congestion. Because ramp meters can be operated to discharge traffic at a measured or regulated rate thus maintaining more uniform speed on the mainline section maximizing the throughput to the freeway within the capacity of a downstream bottleneck and reducing the congestion related accidents. Thus the objectives in this study were to analyze the traffic characteristics on the freeway I-94 with ramp metering system before/after ITS technology in Detroit (Michigan) area compare shifts of the traffic characteristics on the freeway I-94 before/after ITS technology and finally suggest a better ramp metering strategy for the freeway system The following results were obtained: i)Flow occupancies and speeds on the mainline merge section of freeway were shown to be a big difference depending on the peak periods areas and directions based on the distribution of traffic flow characteristics on the freeway. ii)Reduced speed was shown to be more than 5 mph and ramp flow was also shown to be more than 240 vph at peak periods if there was the ramp metering system constructed on the freeway. iii)Ramp metering system was shown to be optimally operated on the freeway if ramp flow could be maximized within the range of over 900 vph and reduced occupancy could be also maximized by no more than 2 percent at peak periods. iv)The average flows on the freeway after the ITS technology were shown to be a decrease of over 20% depending on the peak periods areas and directions when compared with those flow on the freeway before the ITS technology. over 20% depending on the peak periods areas and directions when compared with those speeds on the freeway before the ITS technology. vi)The average metering rates on the freeway after the ITS technology were shown to be an increase of over 10% depending on the peak periods areas and directions when compared with those metering rates on the freeway before the ITS technology.

• 한국도로학회논문집
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• 제18권1호
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• pp.119-129
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• 2016

PURPOSES : The purpose of this study is to develop a methodology for estimating additional carbon emissions due to freeway incidents. METHODS : As our country grows, our highway policy has mainly neglected the environmental and social sectors. However, with the formation of a national green growth keynote and an increase in the number of people interested in environmental and social issues, problems related to social issues, such as traffic accidents and congestion, and environmental issues, such as the impact of air pollution caused by exhaust gases that are emitted from highway vehicles, are beginning to be discussed. Accordingly, studies have been conducted on a variety of environmental aspects in the field of road transport, and for the quantitative calculation of greenhouse gas emissions, using various methods. However, in order to observe the effects of carbon emissions, microscopic simulations must use many difficult variables such as cost, analysis time, and ease of analysis process. In this study, additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service), and the annual additional emissions based on incidents were calculated. According to the results, congestion length and emissions tend to increase with an increase in incident clearance time, number of occupied lanes, and worsening level of service. Using this data, we analyzed accident data on the Gyeong-bu Expressway (Yang-Jae IC - Osan IC) for a year. RESULTS : Additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service) and annual additional emissions caused by accidents were calculated. CONCLUSIONS : In this study, a methodology for estimating carbon emissions due to freeway incidents was developed that incorporates macroscopic flow models. The results of the study are organized in the form of a look-Up table that calculates carbon emissions rather easily.

• 대한교통학회지
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• 제20권7호
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• pp.107-116
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• 2002

충격흡수시설(Crash Cushion)은 고속도로 진출램프의 고어(Gore)지역과 같이 차량이 주행차로를 벗어나 도로상의 구조물과 충돌할 위험이 있는 곳에 설치하여 충돌 전 충격에너지를 흡수하는 역할을 하는 도로변 안전시설물이다. 시설의 설치효과를 높이기 위해서는 사고 발생 가능성을 고려하여 설치여부를 판단하는 기준이 필요하다. 그러나 현재의 충격흡수시설 설치기준은 이와 같은 과정을 제시하지 못하고 있다. 이에 착안하여 본 연구에서는 충격흡수시설의 설치여부 판단기준 개발을 위해 두 가지 형태의 연구를 수행하였다. 첫 번째는 고속도로 진출램프 사고예측모형의 개발이다. 충격흡수시설이 설치되는 고속도로의 고어(Gore)지역에서 발생되는 교통사고와 도로환경적 요인과의 관계를 고려한 사고예측모형을 개발하는 과정으로 교통통계 학자들 사이에서 교통사고의 특성을 잘 반영하여 준다고 알려진 음이항 분포를 사용하였다. 두 번째는 고속도로 진출행동모형의 개발이다. 운전자에 의한 고속도로 진출과정을 단계별로 가정하고 가정된 진출과정에 의해 발생되는 변수들과 사고와의 상관관계를 고려하여 운전행동모형을 개발하였다. 개발된 두 가지 형태의 모형으로 위험도를 수치화하고 편익-비용분석 과정을 통하여 충격흡수시설을 설치여부 판단기준을 제시하였다. 도로환경적 요인과 인적요인을 동시에 고려한 본 연구의 접근방법을 통해 효과적으로 충격흡수시설의 설치여부를 판단할 수 있다.

• 한국ITS학회 논문지
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• 제19권5호
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• pp.1-14
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• 2020

본 연구는 고속도로 교통사고의 사고차량대수에 따른 요인의 영향을 분석하기 위해 다항로짓모형을 이용하여 연구를 수행하였다. 기존의 교통사고 심각도 연구에서는 사고차량대수에 대한 분석이 미흡하였다. 그러나 다중추돌사고는 인명피해 사고로 이어질 가능성이 높고, 사고 지속시간과 사고처리를 위한 사회적 비용이 크기 때문에, 다중추돌사고에 영향을 미치는 요인을 파악하는 것이 중요하다. 따라서 본 연구에서는 사고차량대수를 사고의 요인이 아닌 사고의 결과로 해석하고, 이에 미치는 사고요인별 영향을 분석하였다. 분석결과, 야간사고와 고속도로 본선, 터널, 교량에서 발생한 사고, 운전자과실, 도로장애물, 노면문제로 인한 사고, 내리막 경사, 중차량 연관 사고가 다중추돌사고로 이어질 가능성이 높은 것으로 분석되었다.

• 한국도로학회논문집
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• 제9권2호
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• pp.77-87
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• 2007

고속도로의 교통사고는 다양한 원인들에 의해 발생되고, 그중 운전자의 부주의는 가장 중요한 교통사고 원인으로 알려져 있다. 주의 및 규제표지와 노면요철포장 등의 도로안전시설은 이러한 운전자 부주의를 막기 위해 설치 운영되고 있다. 본 연구에서는 서해안고속도로 일부구간에 설치된 길어깨-노면요철포장의 교통사고감소 효과를 분석하기 위해 C-G 방법 (Hauer에 의해 개발된 비교그룹을 이용하는 사전 사후 분석방법)을 수행하였다. 분석결과 길어깨에 도로요철포장을 설치한 도로는 설치하지 않은 도로에 비해 차도이탈사고가 연간 2.43건 정도 감소한 것으로 나타났으며 감소율은 0.38(표준편차 0.21)인 것으로 나타났다. 차도이탈사고는 교통사고 중 길어깨-노면요철포장 설치에 가장 민감하게 영향을 받는 사고형태이다. 본 연구를 통해 서해안고속도로에 설치된 길어깨-노면요철포장은 교통사고 감소에 기여한 것으로 분석되었으며, 특히 차도이탈사고가 현저하게 감소된 것으로 분석되었다.

• 산업경영시스템학회지
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• 제22권49호
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• pp.125-133
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• 1999

Nonrecurring congestions are generally caused by random or less predictable events, such as accidents, spilled loads stalled or broken-down vehicles that, temporarily reduce the capacity of the freeway. The purpose of this paper is to present the effect of incidents on the traffic congestion on the urban freeway by simulation method. The simulation scenario is composed of two level traffic conditions, two level incident severities, and eight level incident durations. After incident, the recovering duration to the normal traffic flow, increased by linear of incident duration. Total vehicles travel time increased and average travel speed decreased by squares curve of incident duration. Considering incident impacts, incident management system is evaluated the major function of the urban freeway traffic management system. Also, necessary the related research to detect, verify, and develop effective response strategies for traffic incidents.

• 한국안전학회지
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• 제26권4호
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• pp.127-134
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• 2011

A traffic accident which happens in Expressway during dense fog is more likely to cause the sequential accidents and high death rate. So, the preventive measures shall be taken at dangerous areas to enhance the efficiency of roads and minimize the accidents and the resultant damages. So, it is necessary to find out the characteristics of freeway zone which has high risk of fog occurrence and to establish the comprehensive safety strategy on installation and operation of the safety equipment. In this study, I developed a fog forecasting model by using the freeway fog data. This model can be used as the fog forecasting model in dealing with fog problems when new road is planned. The model was developed by using a statistical analysis technique or the regression analysis, focusing on the variables such as geographical features and regional conditions, distances to water sources and the area of water source. I have segmented the models by classifying the area into inland area and coastal area. The distance to water source and area of the water source located around the freeway were found to be main factors causing fog.

• 한국도로학회논문집
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• 제9권4호
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• pp.65-74
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• 2007

노면요철포장은 1950년대 처음 설치된 후 사고감소효과에 대하여 여러 가지 연구가 있어왔다. 대부분의 연구에서 주로 졸음과 부주의 사고를 예방하는 것으로 알려져 있다. 본 논문에서는 고속도로 377개소에서 4년 동안 수집한 교통사고를 바탕으로 노면요철포장 설치 전 후에 사고감소원인과 환경을 분석하였다. 분석결과 노면요철포장 설치 전 후 교통사고를 비교할 때 -200건/2년(-32.3%) 감소하여, 노면요철포장 설치시 사고감소 효과가 있는 것으로 나타났다. 세부교통사고 원인분석결과 노면요철포장 설치효과가 유의하다고 할 수 있는 교통사고원인 항목을 제시할 수 있었다. 졸음, 과속, 주시태만, 부주의, 차량결함, 안전거리 미확보 교통사고감소가 유의하였다. A, B, C 등급 사고의 경우 교통사고감소가 유의하였다. 기상 상태 원인분석결과 맑음, 비, 흐림 기상상태에서 노면요철포장으로 인한 교통사고감소가 유의하였다. 본 논문 결과는 그동안 졸음 혹은 부주의 교통사고우려에 대응하도록 한 기존 노면요철포장 설치기준보다 원인인자를 명확히 하고 확장하여 고속도로 교통사고감소에 기여할 것으로 생각된다.