• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.45-60
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• 2003

A median is a safety feature most commonly used to separate opposing traffic on a divided highway. In designing highways, the selection and installation of a median can be a critical part from a safety viewpoint because road crossing accidents are definitely more serious than other accidents. In regard to the important function of the median. the proper countermeasure ought to have been provided and thorough study should have been carried out. In this paper, traffic accident data are analyzed to examine the accident reduction effect of the median, which are gathered from all over 4-lane national roads in Korea. The traffic accident data were categorized into two groups by the existence of a median. For more effective analysis, the data have been classified by accident type, severity. and occurrence time. To compare the effectiveness of median installation, not only the accident frequency but also the accident severity, EPDO. and the occupancy rate of specific accidents have been used as a mode of effectiveness. The analysis of the effectiveness of medians shows that both the accident frequency and the accident severity could decrease by providing a median. Also the section where a median was supplied showed the improvement of overall safety through fewer serious and fatal crashes as well as fewer head-on crashes. Therefore, conclusions can be drawn from results of this study that the median installation is an important means to increase the safety of over 4-lane national roads. This study is expected to provide the reasonability of the median installation by identifying the reduction of traffic accident after the median installation and to play a major role in selecting sections where the median is to be offered.

• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.119-129
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• 2014

This study aims to evaluate the accident reduction effects of 'Section Speed Enforcement System' (SSES) operation in freeways. In pursuing the above, this study collects the accident data for 5 years (2 years before operation and 3 years after operation) at all 9 sections where SSESs are operated, and evaluates annually the effects before and after operation using the comparison group method (C.G. Method). The measures of effectiveness are total accidents (TAs), fatal and serious accidents (FSAs), total injuries (TIs) and fatal and serious injuries (FSIs). The main results are as follows. First, TAs and TIs are reduced to 41.7 and 17.1%, respectively. Second, FSAs and FSIs are reduced to 41.7 and 32.2%, respectively. Therefore, SSES has more effectiveness at fatal and serious accident. Third, the accident reduction effect has been increasing, and particularly the effect of 'after three years' is evaluated to be notable.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.65-74
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• 2007

There have been research and studies on rumble strip effectiveness in terms of accident reduction since rumble strips were first installed in 1950's. Research has shown that rumble strips reduce accidents from drowsy and inattentive driving. The present research statistically analyze the accident reduction effect of rumble strips based on accident reports obtained from rumble strip installed 377 places of nation wide freeway lines. Based on the results, rumble strips are effective in reducing accident frequencies 32.3%. The probable various factors inducing accidents are identified. These include drowsiness, speeding, inattentiveness, vehicle defectiveness, and short headways. It was found that rumble strips are effective in reducing A, B, C leveled accidents, and in reducing clear, cloudy, and rainy weather accidents. The results may make clear and expand probable types of accidents that rumble strips would reduce, then reduce the total accidents on freeway lines.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.23-32
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• 2010

Because ROTA(road traffic authority) analyzes the effects of accident reduction based on the data of 1-year after installation of RLC(red light camera), study of accident reduction effects over year after the installation of RLC is very short. This study deals with the traffic accident reduction during 3 years after the installation of RLC. The objective is to analyze the effects of accident reduction by year using EB method. In pursuing the above, the study uses the 951 accident data occurred at the 20 intersections which RLC are installed. The main results analyzed are as follows. First, the safety performance function (SPF) has been developed by the Poisson regression models which are statistically significant. Second, the results of an Empirical Bayes(EB) analyses showed that the accidents were reduced by the range from 2.73 to 38.75% after 1 year, from 6.85 to 47.36% after 2 year, and from 6.04 to 39.31% after 3 year from the installation of RLC.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.21-27
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• 2012

This study deals with the relationships between signal operation and traffic accident of signalized intersections. The objective of this study is to analyze the traffic accident reduction effects on the operation of all-red clearance interval (ARCI). This study gives particular attentions to evaluating the traffic accident reduction effects of ARCI at 37 signalized intersections in Cheongju using before-after evaluation with comparison group. The main results are as follows. First, the number of traffic accidents, fatalities and injuries has changed before operating ARCI and thereafter. Second, the result of before-and-after evaluation with comparison group showed that the number of accidents was reduced by 20.0% and that the number of fatalities and injuries was reduced by 28.0%. Finally, reduction effects from operating ARCI were evaluated to be 6.0~35.0% in the number of accidents and 18.0~37.0% in the number of fatalities and injuries.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.168-181
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• 2023

This study analyzed the effects of traffic enforcement on accident reduction. The results revealed a significant reduction in both overall accidents (28.53%) and fatal accidents (39.44%). Notably, enforcement equipment targeting speed limits of 30 km/h and 50 km/h demonstrated similar accident reduction rates of 42.23% and 25.85%, respectively. However, variations were observed based on accident types and types of traffic violations. Therefore, it is evident that enforcement equipment yields distinct accident reduction effects depending on speed limits and types of traffic accidents. This finding underscores the potential for making informed policy decisions to enhance traffic safety measures.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.130-130
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• 2018

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.129-142
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• 2017

Accident Black Spot Improvement Project is the representative road safety intervention to eliminate environmental risk factors on the roadway by installing road safety facilities. Although it is one of the main road safety projects in Korea, there has been a lack of effort analyzing the traffic accident reduction effects of this project. In this study, therefore, we selected 4,171 road black spots from 2004 to 2013 and investigated the traffic accident reduction effects of 5 road safety facilities by using "Comparison Group(C-G)" method. Through the analysis, it was found that the number of traffic accidents were lowered by 4.45% with traffic islands, 32.17% with road paved markers, and 24.13% with speed cameras, respectively. However, 0.61% with pedestrian fencing and 1.67% with skid resistant pavement were increased on the other hand. In addition, we also analyzed traffic accident reduction facilities' performance on specific types of collision mentioned in manual on road safety facilities by Ministry of Land, Infrastructure and Transport. It was shown that the number of bad weather traffic accidents were reduced by 52.96% with road paved markers, pedestrians accidents were reduced by 62.77% with pedestrian fencing and rear-end collisions were reduced by 26.00% with skid resistant pavement.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.109-117
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• 2008

The first phase of School Zone Improvement Project introduced to enhance the safety of school-routes were completed by 2007 and the second phase of the project will be continued from 2008 to 2012. Since a huge budget is required for the project, there is a need to evaluate how many child-related crashes were reduced through the project, prior to the implementation of the second phase. Therefore, this study aims to analyze the influence of the School Zone Improvement Project on reduction in child-related crashes with data collected from the database of the National Police Agency. This study employed a Before-and-After study with comparison group to assess how many crashes were reduced. The results showed that the number of child-related crashes were decreased by 10, which is about 39% reduction in crash frequencies. With respect to the land use characteristics of school zones, the number of reduced crashes in residential zone, commercial zone, and mixed zone were 2.41, 3.8, and 0.5, respectively. The results may provide a significant implication for the second phase of the project that there is a need to establish different plans for improvement project with respect to land use characteristics.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.291-303
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• 2016

The number of traffic accidents at intersections has been increased over the past decade, and in 2014, accounted for 44% of the total traffic accidents. In addition, since most of road accident black spots include signalized intersections, the improvement of safety on signalized intersection is top priority for national road safety program in Korea. For the decision of most effective action plan for the safety of signalized intersection, this study conducted meta-analyses to assess the effects of various road safety facilities at signalized intersection on traffic accidents. We selected 19 articles regarding the prediction of traffic accidents at signalized intersection and calculated 34 individual effect sizes on 8 variables included in the articles. The results found that there was a statistically significant negative relationship between the occurrence of traffic accident and the presence of all of road safety facilities except an exclusive left turn bay. It shows that most of the road safety facilities could prevent traffic accidents, and intersection channelization has the most effective on the reduction of traffic accidents followed by left-turn acceleration lane, lightning, crosswalk, exclusive right-turn lane and median barrier.