• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.655-666
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• 2021

Purpose: This study is to develop a method for measuring dynamic speeding risks using vehicle trajectory big data and to demonstrate the feasibility of the devised speeding index. Method: The speed behaviors of vehicles were analysed in microscopic space and time using individual vehicle trajectories, and then the boundary condition of speeding (i.e., boundary speed) was determined from the standpoint of crash risk. A novel index for measuring the risk exposure of speeding was developed in microscopic space and time with the boundary speed. Result: A validation study was conducted with vehicle-GPS trajectory big data and ground-truth vehicle crash data. As a result of the analysis, it turned out that the index of speeding-risk exposure has a strong explanatory power (R²=0.7) for motorway traffic accidents. This directly indicates that speeding behaviors should be analysed at a microscopic spatiotemporal dimension. Conclusion: The spatial and temporal evolution of vehicle velocity is very variable. It is, hence, expected that the method presented in this study could be efficaciously employed to analyse the causal factors of traffic accidents and the crash risk exposure in microscopic space using mobility trajectory data.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.4
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• pp.126-136
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• 2013

Aircraft accidents these days, following the mega sizing trend of the aircraft, result in enormous losses of human lives apart from those of property, which cannot be replaced by any means. As most recently, in April 20, 2012, a Boeing 737 passenger plane departed Karachi on an augural flight to Islamabad, Pakistan, crashed close to an express highway on final approach, all 121 passengers and 6 crew members were killed. As such a large number of fatalities have been recorded in aircraft accidents while accident investigation results show that more than 95% of aircraft accidents are now survivable. There are three basic stages in surviving the aircraft accident: surviving the crash impact, the evacuation process and the hostile post evacuation environmental elements. These stages require the cabin crew's expeditious and appropriate actions on the basis of systematic and thorough cabin safety training in order to increase occupants' survivability, along with the passengers' preparedness. In this aspect, this paper examines the issues acting as the impediments to the passenger survival in inflight emergency situations, that are the deficiencies with cabin crew safety training, related performances and the shortcomings in passengers' knowledge on inflight safety information, leading to their inappropriate responses to emergency situations. These issues are analyzed and the root causes are identified, suggesting the resolving countermeasures.

• Journal of Convergence for Information Technology
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• v.9 no.12
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• pp.54-61
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• 2019

Recently, IITS (intelligent integrated transportation system) has been important topic in Smart City related industry. As a main objective of IITS, prevention of traffic jam (due to car accidents) has been attempted with help of advanced sensor and communication technologies. Studies show that car accident has certain correlation with some factors including characteristics of location, weather, driver's behavior, and time of day. We concentrate our study on observing auto correlativity of car accidents in terms of time of day. In this paper, we performed the ARIMA tests including ADF (augmented Dickey-Fuller) to check the three factors determining auto-regressive, stationarity, and lag order. Summary on forecasting of hourly car crash counts is presented, we show that the traffic accident data obtained in Korea can be applied to ARIMA model and present a result that traffic accidents in Korea have property of being recurrent daily basis.

• Journal of Korean Society of Transportation
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• v.32 no.1
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• pp.50-62
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• 2014

The number of traffic accidents has been decreased since 2000; however, the downward trend of crash occurrence has been slower after 2006. A few decades ago, physical improvement projects such as alignment improvement and the installation of safety facilities were usually implemented to decrease the occurrence of traffic accidents, but the effects of physical improvement on safety have been gradually decreased. The main objective of this study is to identify how the drivers' characteristics affect and/or are related to traffic accidents. Most of previous works have focused on revealing the difference of the nature of the drivers between the drivers who have no experience and the drivers with experience of traffic accidents. This study tries to analyze the habitual accidents proneness through a survey of drivers' personalities for drivers who were involved in traffic accidents at least once. As a result, nine personality factors were found to be statistically significant: Neuroticism(N), Lie(L), Psychoticism* Neuroticism(PN), Psychoticism*Lie(PL), Extraversion*Lie(EL), Neuroticism*Lie(NL), Impulsiveness(IMP), Venturesomeness(VEN), Empathy(EMP). Among these factors, single character factors were found to increase accidents, whereas complex factors were found to decrease the occurrence of accidents.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.7-12
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• 2018

Injury mechanisms of lower extremity injuries in motor vehicle accidents are focused on fractures, sprains, and contusions. The purpose of this study is to evaluate the analysis of lower extremity injury mechanism in occupant motor vehicle accident by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 1,699 patients due to motor vehicle crashes, 88 (5.2%) received a diagnosis of lower extremity fracture and 141 (8.3%) were the severe who had ISS over 15. Nevertheless during 19 months for research, it was difficult to build up in-depth database about motor vehicle crashes. It has a limitation on collecting data because not only the system for constructing database about motor vehicle crash is not organized but also the process for demanding materials is not available due to prevention of personal information. For accurate analysis of the relationship between occupant injury and vehicle damage in motor vehicle crashes, build-up of an in-depth database through carrying out various policies for motor vehicle crashes is necessary for sure.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.6
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• pp.613-618
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• 2015

In recent years, WorldSID has been continuously developed and investigated to be the representative biofidelic anthropomorphic test device (ATD) as well as the device for replacement of the current EuroSID-2. In Korea, the side impact accident is one of the major severe accidents in terms of the number of accidents and fatality. Since 2003, the side crash test with a speed of 50 kph in the perpendicular direction has been initiated as a safety standard with EuroSID-1 at the first stage. Simultaneously, a 55 kph impact test has been conducted as a part of Korean New Car Assessment (KNCAP). Currently, only EuroSIDE-2 is accepted as a regulatory tool for vehicle certification and KNCAP. The tests with WorldSID are conducted experimentally in order to use WorldSID of the KNCAP in near future.

• Journal of Auto-vehicle Safety Association
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• v.6 no.1
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• pp.22-26
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• 2014

Fatality of accidents on curved roads where rollover accidents are likely to take place was higher than that on straight roads. We ought to investigate factors affecting injury severity of occupant in a vehicle rollover accident. From January 2011 to December 2013, we collected data about rollover motor vehicle crash accident. We surveyed occupant's injury, vehicle type, safety devices, type of rollover accident and the number of turn in accident. Of the 132 subjects, 56.1% were males, 50.8% were drivers, 48.5% fastened seat belt, and air bag deployed in 12.1%. Among injuries sustained head, chest and abdomen were major sites of severe injury(Abbreviated injury scale>2). Seat belt use, rollover type, and the number of 1/4 turn were found to have significant positive correlations with Injury Severity Score. The regression analysis herein found significance in safety belt use and the number of 1/4 turn. Seat belt use was a significant factor affecting injury severe of occupant in rollover accident.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.67-74
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• 2014

Recently, the number of road construction is increasing by industrial development. According to this industrial tendency, the number of traffic accidents are consistently increasing due to increasing number of vehicle on the road. This is mainly because traffic accidents are occurred by various parameter such as negligence of driver, vehicle defects, state of unstable road, natural environment etc. Lane department of vehicles from guardrail is occurring frequently. This type of accident is caused by vehicle performance improvement and shape of vehicle, weak guardrail installation and maintenance. Guardrail has the purpose on prevention such as prevention of traffic accident and prevention of deviating out of road, minimizing damage of driver and vehicle by collision as well as entry into the road through guardrail. Stability evaluation test of guardrail verifies the behavior of guardrail through the crash of truck. At this time, the crash condition has 100 km/h of velocity and $15^{\circ}$ of impact angle. In the case of ground condition, filling slope condition has relatively high bearing capacity of infinite ground towards the test. Guardrail is generally installed on road of shoulder in fill slope in korea. It is possible for stability problem to deteriorate ground bearing capacity in Guardrail in fill slope. The existed study towards stability of guardrail has been carried out in the infinite ground. However, the study on the behavior of fill slope with guardrail is not performed by vehicle collision. Therefore, In this study, the numerical analysis using LS-DYNA was executed for verification on behavior of fill slope with guardrail through vehicle collision. This numerical analysis was carried out with change of embedded depth on installed guardrail post in shoulder of fill slope by vehicle collision and 8 tonf truck crash providing at NCAN (National Crash Analysis Center). As the result, displacement and stress on fill slope are decreased in accordance with the increase of embedded depth of guardrail post. Ground bearing capacity is deteriorated at depth of 450 mm form shoulder of road on fill slope.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.12-28
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• 2019

Road geometry is one of the many factors that cause crashes, but the effect on traffic accident depends on weather conditions even under the same road geometry. This study identifies the variables affecting the crash severity by matching the highway accident data and weather data for 14 years from 2001 to 2014. A hierarchical ordered Logit model is used to reflect the effects of road geometry and weather condition interactions on crash severity, as well as the correlation between individual crashes in a region. Among the hierarchical models, we apply a random intercept model including interaction variables between road geometry and weather condition and a random coefficient model including regional weather characteristics as upper-level variables. As a result, it is confirmed that the effects of toll, ramp, downhill slope of 3% or more, and concrete barrier on the crash severity vary depending on weather conditions. It also shows that the combined effects of road geometry and weather conditions may not be linear depending on rainfall or snowfall levels. Finally, we suggest safety improvement measures based on the results of this study, which are expected to reduce the severity of traffic accidents in the future.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.103-114
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• 2011

In this study, we discuss a fatal accident severity model obtained from the analysis of 112 crash sites collected since 2000, and the resulting relationship between fatal accidents and roadway geometry design. From the 720 times computer simulations for improving driving safety, we then reached the following conclusions:. First, the result of cross and frequency-analyses on the car accident sites showed that 43.7% of the accidents occurred on the curved roads, 60.7% on the vertical curve section, 57.2% on the roadways with radius of curvature of 0 to 24m, 83.9% on the roads with superelevation of 0.1 to 2.0% and 49.1% on the one-way 2-lane roads; vehicle types involved are passenger vehicles (33.0%), trucks (20.5%) and buses (14.3%) in order of frequency. The results also show that the superelevation is the most influencing factor for the fatal accidents. Second, employing the Ordered Probit Model (OPM), we developed a severity model for fatal accidents being a function of on various road conditions so as to the damages can be predicted. The proposed model possibly assists the practitioners to predict dangerous roadway segments, and to take appropriate measures in advance. Third, computer simulation runs show that providing adequate superelevation on the segment where a fatal accident occurred could reduce similar fatal accidents by at least 85%. This result indicates that the regulations specified in the Rule for Road Structure and Facility Standard (description and guidelines) should be enhanced to include more specific requirement for providing the superelevation.