• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.127-135
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• 2009

Most traffic information that drivers receive while driving are stored in their short-term memory and disappear within a few seconds. Contemporary modeling approaches using a dummy variable can't fully explain this phenomenon. As such, this study proposes to use utility functions of real-time in-vehicle traffic safety information (IVTSI), analyzing its safety impacts based on empirical data from an on-site driving experiment at signalized intersection approach with a limited visibility. For this, a driving stability evaluation model is developed based on driver's driving speed choice, applying an ordered probit model. To estimate the specified utility functions, the model simultaneously accounts for various factors, such as traffic operation, geometry, road environment, and driver's characteristics. The results show three significant facts. First, a normal density function (exponential function) is appropriate to explain the utility of IVTSI proposed under study over time. Second, the IVTSI remains in driver's short-term memory for up to nearly 22 second after provision, decreasing over time. Three, IVTSI provision appears more important than the geometry factor but less than the traffic operation factor.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.65-77
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• 2013

Recent advanced sensors and communication technologies have been widely applied to advanced safety vehicle (ASV) for reducing traffic accident and injury severity. To apply the advanced safety vehicle technologies, it is important to quantify the safety benefits, which is a fundamental for justifying application. This study proposed a methodology for quantifying the effectiveness of the advanced driver assistant system (ADAS), and applied the methodology to lane departure warning system (LDWS) and automatic emergency braking system (AEBS) which are typical advanced driver assistant systems. When the proposed methodology is applied to 2008-2010 gyeonggi-province crash data, LDWS would reduce about 10~14% of relevant crashes such as head-on, run-off-the road, rollover and fixed-object collisions on the road. In addition, AEBS could potentially prevent about 50% of total rear-end crashes. The outcomes of this study support decision making for developing not only vehicular technology but also relevant safety policies.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.103-111
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• 2011

The speed is one of the significant factors affecting accident occurrence. In particular, freeway accidents are highly associated with the speed because vehicles travel on the freeway at higher speed leading to greater potential of severer injury. Efforts attempting to relating speed with accident occurrence have not been significantly made in Korea. The objective of this study is to model the relationship between speed and accident rate on freeways. Loop detector data and accident data obtained from a stretch of Kyungboo freeway during the recent five years, 2005-2009, were used to establish the model. Multiple linear regression analyses showed that median, minimum and standard deviation of speed were contributing variables in the model. The statistical significance identified by the analyses supports the feasibility of the model in evaluating various transportation policies and operations strategies in terms of traffic safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4634-4643
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• 2014

The objective of this study was to analyze the effects of LED safety block using the government database. To evaluate these effects, the night accident data was obtained from 2007 to 2011 from the database. At the LED-installed area, compared to the uninstalled area, the number of night traffic accidents, injured and mortality had decreased by 26.2%, 21.2% and 38.3%, respectively. The LED-installed intersections are safer than the LED-uninstalled roads from a traffic accidents perspective. In conclusion, a LED safety block is quite effective in decreasing the number of traffic accidents. Although this study was conducted using the data from Changwon city, where LED safety blocks have been installed so far, these results can provide valuable data to other cities considering the implementation of these LED safety blocks.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.169-178
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• 2008

Level of Service (LOS) is one of ways to evaluate operational conditions. It is very important factor in evaluation especially for the facility of highways. However, some studies proved that ${\upsilon}/c$ ratio and accident rate is appeared like a second function which has a U-form. It means there is a gap between LOS and safety of highway facilities. Therefore, this study presents a method for evaluation of a signalized intersection which is considered both smooth traffic operation (delay) and traffic safety (accident). Firstly, as a result of our research, accident rates and EPDO are decreased when it has a big delay. In that reason, it is necessary to make a new Level of Service included traffic safety. Secondly, this study has developed a negative binominal regression model which is based on the relation between accident patterns and stream. Thirdly, standards of LOS are presented which is originated from calculation between annual delay costs and annual accident cost at each intersection. Lastly, worksheet form is presented as an expression to an estimation step of a signalized intersection with traffic accident prediction model and new LOS.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.59-67
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• 2004

On January 1, 2003, the motor vehicle management system in Korea was transformed from government's vehicle type approval to manufacturer's self-certification. The motor vehicle recall system with self-certification is an essential mechanism to place the liability of the vehicle defects on manufacturers and hence protect consumers from automobile accidents. This study provides a methodology to measure the benefits of motor vehicle recall system in two categories: benefits of reduction in traffic accidents and benefits of severity reduction in traffic accident. Applying the proposed methodology, the benefits of implementing motor vehicle recall system in Korea were estimated. It was estimated that 745 traffic accidents, 12 fatal accidents, and 1473 injury accidents were respectively reduced in 2002 due to implementation of motor vehicle recall system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.775-789
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• 2008

The Office for Government Policy Coordination announced in 2006, september that a scheme of pre-signal would show remarkable outcome to reduce traffic accidents. Therefore, the Ministry recommended applying preferentially the pre-signal scheme to enhancement projects for high accident frequency areas. In case that the suggested pre-signal was unilaterally introduced to the enhancement projects at intersections, it might rather cause a big trial and error in terms of traffic safety. Hence, on the basis of quantitative analysis, this study was to indicate a pre-signal's effectiveness to reduce the traffic accidents, to illustrate a trend of the accident type due to the pre-signal, and to introduce intersection type that could be appropriate for the pre-signal. The methodology adopted Comparison-Group Method which was developed by Hauer. Through this methodology, overall effectiveness to reduce the accidents is considered positive but individual effectiveness by intersection and by accident case was different. All cases of the accidents at small scale intersection demonstrated positive results to reduce its accidents, while in case of frontal collision and side-right angle collision out of the accident types, the installation of pre-signal rather caused a negative result increasing the accident in terms of the traffic safety. I hope that this study would be a useful reference for future development of the estimation of accident effectiveness. Thus, when the pre-signal is being installed in the big intersection, it is recommended operating the installation concerning carefully improvements about muliple aspects as traffic operation, traffic facility, human factor etc.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.63-77
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• 2023

This study applies reinforcement learning to effectively operate expressway hard shoulder running (HSR). An HSR algorithm was developed, and its effectiveness was evaluated using the VISSIM microscopic simulation program. The simulation evaluated two aspects: mobility and safety. The DQN-based HSR algorithm found speed improvement of up to 26 km/h. Compared to the current method, the difference in the number of conflicts was not significant. Considering the results, a DQN-based HSR operation has a clear effect, and it is necessary to consider adjusting the current operational criteria.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.51-62
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• 2008

An innovative feature of this study is to propose a methodology for evaluating safety performance in real time based on vehicle trajectory data extracted from video images. The essence of evaluating safety performance is to capture unsafe car-following and lane-changing events generated by individual vehicles traveling within video surveillance area. The proposed methodology derived three indices including real-time safety index(RSI) based on the concept of safe stopping distance, time-to-collision(TTC), and the collision energy based on the conservation of momentum. It is believed that outcomes would be greatly utilized in developing a new generation of video images processing(VIP) based traffic detection systems capable of producing safety performance measurements. Relevant technical challenges for such detection systems are also discussed.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.65-80
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• 2005

대부분의 국가들이 노선버스의 운영을 공공부문에서 담당하고 있으나 우리나라를 비롯한 일부에서만 민간이 운영하고 있어 시민들을 위한 공익성만을 추구 할 수는 없는 입장이며 노선의 선정 또한 사업자와 공공이 협의하여 시행할 수밖에 없다. 이를 개선하기 위하여 버스노선 개편, 공동배차제 등 개선방안을 많은 지자체에서 시행하였지만 시민${\cdot}$업체${\cdot}$공공부문에서의 합의 도출은 지난한 상황이며 실행력이 없는 계획이 되고 있음을 여러 사례에서 볼 수 있다. Internet등 통신기술의 급속한 발달에 따라 통신을 통한 의사표출이 자유롭고 용이해지면서 일반지자체의 경우에 전체 민원 중 교통부문이 차지하는 민원이 $50\%$를 상회하고 있으며, 교통민원 중 $45.3\%$가 노선버스의 정시성 확보 및 운전기사의 불친절, 무정차 통과 등에 관한 것으로써 시민들이 가장 알고싶어 하는 사항이 버스의 실시간 운행상황임을 알 수 있었다. 따라서 본 연구에서는 실시간 버스정보제공을 통해 노선버스 이용자들의 대기시간 감소 및 이용편의를 증진시키고, 이를 통해 승용차 이용자를 대중교통수단으로 유도하여 대중교통을 활성화시키는 버스정보시스템(BIS ; Bus Information System)을 정립하며, 충주시 교통여건을 감안한 버스정보시스템 도입전략을 수립하고, 도입에 따른 기대효과를 분석하여 합리적이고 효과적으로 적용할 수 있는 지방자치단체 특히 충주시의 지능형 교통정보 시스템을 마련하는데 그 목적이 있다.