• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.129-134
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• 1999

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.179-186
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• 2001

As the freight traffic becomes heavier, the high speed of existing freight cars is essential instead of the construction of a new railway. The high speed can be achieved by the design modifications of the freight bogie. In this paper, an analytical model of freight bogie including the lateral force between rail and the flange of wheel is developed to decide the critical speed, which activates a hunting motion and tells the running safety of freight bogie. The dynamic responses of the analytical model were compared with an experimental data from a running test of a freight bogie and showed good agreements between them. The analytical model is used to find the design modifications of the freight bogie by parameter studies. The results show that the reduction of wheelset mass ratio and the increase of the axle distance of the freight bogie can increase the critical speed, but the primary lateral stiffness has little effects on the critical speed. And this also study shows that smaller wheel conicity deteriorates the running safety of the freight car, which means the overhauling of the wheel of freight bogie should be done regularly.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.53-58
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• 2006

Recently, vessel's average speed in the sea becomes fast because of the increasing of high-speeds vessel like a container ship and ferry. So, it is considered that speed control in the korean narrow waterway isn't the proper vessel traffic management, now. And, there is a rare paper studied about speed control quantitatively and numerically, especially speed control is discussing continuously, as abrogation of Incheon Port's speed control and alleviation of Kwangyang Port's speed control a according to navigating mariner's request. After this paper replayed the navigation traffic flow in the straight waterway using marine traffic flow simulation, the Environmental Stress Model is introduced to evaluate difficulty of each vessel's traffic.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.22-30
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• 2015

Recently ITS have been increasingly applied on the roads to resolve traffic problems. Especially, Variable Message Sign (VMS), which is the one of ITS for traffic management and traffic safety, can be used for providing information about road conditions, climate conditions. In this study, data acquisition and statistical analysis were conducted for estimating safety impacts of providing traffic information through VMS. As a result of analyzing traffic characteristics before and after providing traffic information through VMS, average travel speed was decreased and vehicles tended to drive on centerline of lanes in 1st and 2nd lane after providing traffic information through VMS. Also, in order to analyze safety impacts of provided VMS traffic information, traffic safety hazard zone was established in each lane and probability distributions of passing traffic on the study area was estimated through Anderson-Darling Test. As a result of this, safety impacts of VMS traffic information in 1st lane could, on average, increase in left and right side of the lane by 0.69% and 7.07%, respectively. In case of 2nd lane, safety impacts could, on average, increase in left and right side of the lane by 2.71% and 0.02%, respectively.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.135-140
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• 2017

This study deals with the safety of roundabout. The purpose of this study is to analyze the factors affecting the pedestrian accidents of roundabout near schools. In pursuing the above, this study gives particular attentions to comparatively analyzing the pedestrian accident by number of entry and circulatory lane. The traffic accident data from 2013 to 2015 are collected from TAAS data set of Road Traffic Authority. To develop the pedestrian accident model, the Poisson and negative binomial models has been utilized in this study. Such the dependent variable as the number of pedestrian accidents and the 24 independent variables as geometry, traffic volume and others are used. The main results are as follows. First, 3 Poisson and 2 negative binomial models(${\rho}^2$ of 0.153~0.426) which are all statistically significant are developed. Second, the common variable of models based on the number of circulatory roadway lane is analyzed to be the entry lane width and that of the number of entry lane is evaluated to be the design speed. Also specific variables are evaluated to splitter island, roundabout sign, number of approach road, bus stop and elementary school. Finally, the design speed might be expected to decrease the number of pedestrian accidents near schools.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.13-25
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• 2024

In traffic management, gaps in understanding traffic conditions continue to exist. While the self-belonging problem indicator develops relative to speed, belonging, and self-based relative inclination, it does not apply elimination criteria that may indicate situations that contrast with attribute-specific problems. In this study, we develop integrated indicators that specify communication situations and safety levels for modeling. We review indicators of changes in traffic conditions and raise safety issues, reviewing the indicators so that ITS data can be applied, analyzing the relationships between indicators through factor analysis. We develop combined, integrated indicators that can show changes and stability in traffic situations and that can be applied in traffic information centers to contribute to the development of a traffic environment that can monitor related traffic conditions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.627-635
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• 2014

Currently the highest speed limit on the road traffic congestion or because you can not cope with climate change to cause a traffic accident may be a factor. According to the Road Traffic Act as well as 20% to 50% in case of inclement weather, but the driver must slow speed left to the judgment of the difficulties, and to slow the vehicle and the relative velocity between the vehicle does not run longer be a big influence on the environment and safety. Thus, variable speed control for drivers on the road, specify the appropriate maximum speed limit in bad weather It keeps motorists slowed the run rate to prevent accidents or reduce the severity of accident damage is expected to be possible. The purpose of this study is the frequent traffic accidents Continuous Busan (City Freeway) around the variable speed control in the appropriate sections so that it can be done by analyzing the characteristics of traffic accidents were the severity of the accident. Highway and urban environment, the geometry of the structure because it has a lot of Curved planar point compared to wet and dry road surfaces by simulated rain wet had bom the more the speed the greater the risk of an accident was the result. Based on these results, the primary section, first urban highway tunnel, near the lamp, near Toll Plaza, near binary Outlet after considering various factors such as speed reduction is needed in the first period by conducting awareness and recognize the need for the participation of the driver and the future city installation and operation of highways in all sectors is expected to be expanded.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.4
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• pp.359-365
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• 2013

There are more than 10 ships and jetfoil passenger ships with speeds of 30~40 kts navigating between Japan and Busan ports per hour. Busan port has the highest density of traffic among the Korean ports and waterways. Jetfoil ships are the most frequently encountered amongst other vessels and about 18 % of passing jetfoil vessels violated port regulations. Based on the analysis of traffic survey carried out for 10 days, jetfoil vessels often overtook other vessels in route and deviated with high speed. This paper verified a proper speed and how to navigate in or out route of jetfoil ships by marine traffic flow simulation. A acceptable navigation speed for jetfoil vessel's mariner was calculated at less than about 32kts in Busan Port. It is a little different that shiphandling difficulty of jetfoil was almost the same whether passing in and out route in Busan Port. This paper proposes that the passing time of jetfoil ships should avoid the peak time to improve the traffic safety in Busan Port.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.55-63
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• 2020

Road traffic noise is a major complaint. Porous pavement (PP) has been proposed as an effective method for reducing road traffic noise, but it has not been applied much due to the lack of quantitative evaluation. In this study, the noise reduction of single-layer porous pavement (SLPP) and double-layer porous pavement (DLPP) was evaluated. The noise was measured using the CPX method, and the driving speed was measured every 10km/h from 50km/h to 80km/h. The differences in noise level between the two PPs were statistically significant. The driving speed had no significant effect on the difference in noise between the two PPs. The DLPP showed a 6.6dB(A) reduction in average and a 6.3dB(A) reduction at the 95% confidence level compared to the SLPP. Reducing noise by 5dB(A) is equivalent to reducing traffic to 1/3 or lowering the vehicle's speed to 1/2. Sensitively, it is possible to recognize a 3dB(A) and 5dB(A) difference. The DLPP and SLPP were very effective in reducing traffic noise.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.97-107
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• 2018

PURPOSES : The effects on traffic accidents change with the changing environment. Accordingly, this study analyzes the characteristics of traffic accidents based on the personal characteristics (gender and age) of drivers, and those of 25 autonomous districts in Seoul, and suggests improvements. METHODS : Based on data pertaining to traffic accidents in Seoul, the analysis of accident characteristics was conducted by categorizing the types of traffic accidents according to the drivers' gender and age, and characteristics of 25 autonomous districts in Seoul. Further, for statistical verification, the SPSS software was used to derive influence variables through a multinomial logistic regression analysis, and a method for reducing traffic accidents was proposed. RESULTS : Analysis results show that males tend to be more involved in speed-related accidents and females in low-experience driving-related accidents such as those during parking and alleyway driving. In addition, variables such as age, automobile type, district, and day of the week are found to influence accident types. CONCLUSIONS : This study analyzed the accident characteristics based on personal and city characteristics to reflect the sociological characteristics that influence traffic accidents. The number of traffic accidents in Korea could be decreased drastically by implementing the results of this study in customized safety education and traffic maps.