• International Journal of Highway Engineering
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• v.17 no.5
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• pp.39-46
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• 2015

PURPOSES: The operational characteristics of roundabouts are generally influenced by location as well as traffic volume. The goal of this study is to develop urban and rural roundabout accident models and to discuss safety improvement guidelines based on the model. METHODS : To analyze accidents, count data models are utilized in this study. This study used accident data from 2010 to 2013 for 56 roundabouts collected from the Traffic Accident Analysis System (TASS) of Road Traffic Authority. Poisson and negative binomial regression models were developed for this study using NLOGIT 4.0. RESULTS : The main results are as follows. First, the hypotheses that there are distributional differences in the number of accidents and injuries/fatalities among rural and urban roundabouts were accepted. Second, Poisson and negative binomial regression accident models, which were all statistically significant, were developed. Seven independent variables, which were statistically significant, were adopted. Third, the common variable of models was evaluated to be traffic volume. CONCLUSIONS : This study developed two negative binomial roundabout accident models and suggested some accident reduction strategies. The results are expected to give some implications to the safety improvement of roundabout.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.49-56
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• 2021

The purpose of this study is to develop a methodology to select a cluster of night traffic accidents using CRP (Continuous Risk Profile) analysis. the other purpose of this study is to present the characteristics of the traffic accident cluster section selected at night using CRP analysis. The CRP analysis was performed considering traffic volume of target routes through traffic accident data. In addition, variables were set according to the freeway sections. the method of subtracting the daytime CRP from the nighttime CRP was used to analyze the nighttime traffic accident. As a result, Using the CRP analysis, the sections of hotspot were identified and plotted based on traffic accidents. Also, the sections where traffic accidents are frequent were those where IC or Tunnels were installed, and there was a deviation from the general section. In conclusion, CRP analysis could be used to calculate the frequent section of specialized traffic accidents at night, and it was selected as a point in need of improvement due to the frequent occurrence of specialized traffic accidents at night in the section where IC or tunnel facilities are installed. In addition, it is inferred that the number of specialized traffic accidents at night in the section where IC or tunnel facilities are installed is a factor in the problem of night visibility due to lighting facilities.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.54-63
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• 2023

Pedestrian traffic needs to be accurately quantified to predict effectively pedestrian traffic accidents, however, pedestrian traffic is more difficult to measure than vehicle traffic. In this study, we suggest the time-and cost-effective application of mobile closed-circuit television (CCTV) using a smartphone as an alternative that can collect and analyze real-time data with little. In the present investigation, the pedestrian-vehicle conflict that can develop into an accident was defined as the pedestrian accident exposure. After installing mobile CCTV in 40 sections of Dongseong-ro, Daegu, the pedestrian accident exposure was estimated through negative binomial regression analysis using the collected data. The results of the analysis showed statistically significant changes in the pedestrian accident exposure variables. Based on the present results, a pedestrian accident exposure estimation model was developed which can be used in sections where pedestrian accidents may occur.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.341-350
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• 2021

Purpose: The purpose of this study is to present an analysis method to select priorities for areas where the traffic safety system is applied to reduce pedestrian accidents. Method: Using Kernel density analysis using the coordinate information of the accident point, we performed density analysis of elderly walking accidents and elderly jaywalking accidents, and analysis of the weight of two types of walking accidents. Result: As a result of density analysis of the weight considering elderly jaywalking accidents, it was analyzed that the density of pedestrian traffic accidents for th elderly was higher in Gunsan-si, Jeongeup-si, and Gimje -si compared to Jeonju-si, where the number of elderly pedestrian accidents were high. Conclusion: The analysis results of this study are judged to be possible to use objective indicators for the selection of target sites for the introduction of the traffic safety system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1142-1148
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• 2006

Actually, a present traffic accident detection system is subsisting limitation of accurate distinction under the crowded condition at intersection because the system depend upon mainly the image information at intersection and digital image processing techniques nearly all. To complement this insufficiency, this article aims to estimate the level of present technology and a realistic possibility by analyzing the acoustic characteristic of crash sound that we have to investigate fur improvement of traffic accident detection rate at intersection. The skid sound of traffic accident was showed the special pattern at 1[KHz])$\sim$3[KHz] bandwidth when vehicles are almost never operated in and around intersection. Also, the frequency bandwidth of vehicle crash sound was showed sound pressure difference over 30[dB] higher than when there is no occurrence of traffic accident below 500[Hz].

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.111-118
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• 2018

Korea is facing a surge in the aging population, showing that population aged 65 and above will be accounted for 42.5% of the total population in 2065 with the emphasis on the over-80 population consisting of 19.2%. In response to this abrupt change in population structure, the number of traffic fatality accident referring to older driver as aged 65+ years had been increasing from 605 fatalities in 2011 to 815 fatalities in 2015 resulting in increases in 34.7% in oppose to happening to decreases in 17.2% about non-older driver. With Logit analysis based on Newton-Raphson algorithm utilizing older driver's traffic fatality data for the 2011-2015 years, it was found that the likelihood of an accident resulting in a fatality for super older driver aged 80 years and above considerably increased compared to other older driver with aging classification: 2.24 times for violation of traffic lane, 2.04 times for violation of U-turn, 1.48 times for violation of safety distance, 1.35 times for violation of obstacle of passing; also average annual increase of traffic accident cost related to super older driver was fairly increased rather than other older driver groups. Hence, this study proposes that improving and amending transport safety system and Road Traffic Act for super older driver needs to be urgently in action about license management, safe driving education, etc. when considering the increase of over-80 population in the near future. Also, implementing a social agreement with all ages and social groups to apply with advanced driver assistance system for older driver groups will be able to become a critical factor to enhance safe driving over the face of the country.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.143-149
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• 2017

According to traffic accidents statistics, the number of fatalities, injuries and the rate of increase of traffic accidents have been decreasing over last 5-years. The fatality rate is 1.9 for total accidents but the fatality rate for single vehicle accidents shows a 7.9, which is 4 times greater than the average for all accidents. Single vehicle accidents, usually occur as a vehicle impacts a fixed objects on the roadside as the vehicle runs-off from the road. However, few researches have been conducted considering the accident severity of single vehicle accidents which impact to the fixed objects on the road. The single vehicle accident is directly related to the composition of road cross section, (since it is the required the minimum width of a road for all run-off-the-road vehicles to recover or come to a safe stop). Therefore, this study analyzes the influence of road cross section on traffic accidents to find out the severity of single vehicle accident. To analyze the road elements which are related to the accident severity, the Ordered Probit Model was used. As variables, the element of road cross section such as the radius(m), vertical curve(%), cross sectional grade(%), road width(m). number of climbing lane, median, and curb, were used (as was the 3-years of accidents data). This study found out that cross slope(%), road width(m), and the number of climbing lane are related to the severity of accident. The result of this study could be expected to improve the road safety and to be used as the base data for further road safety research.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.55-63
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• 2003

The traffic accident is the prerequisite of the traffic accident reconstruction. In this study, the traffic accident (forward collision) and traffic accident reconstruction (inverse collision) simulations are conducted to improve the quality and accuracy of the traffic accident reconstruction. The vehicle and tire models are used to simulate the trajectories for the post-impact motion of the vehicles after collision. The impact dynamic model applicable to the forward and inverse collision simulations is also provided. The accuracy of impact analysis for the vehicular collision depends on the accuracy of the coefficients of restitution and friction. The neural network is used to estimate these coefficients. The forward and inverse collision simulations for the multi-collisions are conducted. The new method fur the accident reconstruction is proposed to calculate the pre-impact velocities of the vehicles without using the trial and error process which requires the repeated calculations of the initial velocities until the forward collision simulation satisfies with the accident evidences. This method estimates the pre-impact velocities of the vehicles by analyzing the trajectories of the vehicles. The vehicle slides on a road surface not only under the skidding during an emergency braking but also under the steering. A vehicle over steering or cornering with excessive speed loses the traction and leaves tile yaw marks on the road surface. The new critical speed formula based on the vehicle dynamics is proposed to analyze the yaw marks and shows smaller errors than ones of the existing critical speed formula.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.142-147
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• 2018

This study aims to analyze and discuss the accidents based on the level of traffic culture (LOT). In pursuing the above, LOT are divided into three categories based on the standardized index of traffic culture. Also, this study focuses on developing the accident models using GLM (generalized linear model). The main results are as follows. First, the null hypotheses that the ratios of fatal and serious injured persons (FSI) are the same over categories are rejected. Second, as the common variables, the ratio of turn signal usage and elderly population are analysed to be impacted to the ratio of FSI. Third, the traffic culture indicators among 5 accident factors which give impact to 'high level' are judged to affect the reduction of FSI. Fourth, compared to other levels, the traffic law violations among 7 accident factors of 'medium level' are estimated to influence the increase of FSI. Finally, in 'low level', the increasing ratio of traffic culture index compared to that of previous year and the number of hospital beds per person are evaluated to be significant to reducing the ratio of FSI. This study can be expected to give some policy implications to regional traffic safety policy-making.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.33-43
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• 2022

The number of car crashes increases along with the increasing number of vehicles. Hence, diverse initiatives on traffic accidents have been implemented, targeting zero crash fatalities. According to the 3rd Traffic Safety Master Plan of 2016, the current standard selecting road accident black spots prioritizes locations with the high cumulative death toll. While this standard is suitable for roads that a city government manages to some extent, it is not suitable for roads less than 20 meters that a borough (Gu) handles. The roads under the supervision of a borough do not have enough death toll, and thus improvements on its road accident black spots are highly limited. In addition, discovering the causes of traffic accidents is not easy when the number of car accidents is obtained by considering only fatal accidents, which are relatively low in number. Therefore, including all traffic accidents might identify causes of accidents and result in better advancements. Therefore, this research follows rational decision-making and suggests new National Traffic Safety Master Plan standards. These new standards are obtained by comparing accident costs between the location of fatal crashes and road accident black spots. The analysis result shows that considering all types of accidents yields better results. For example, a Three-way Intersection in front of Zion Day Care Center, one of the selected spots under the current standard, has lower road crash costs than Sinchon Intersection, a selected spot under a new standard. Therefore, the study concludes that the standards to select road accident black spots need to include traffic accident severity and road crash costs.