• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.1-11
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• 1998

Focuses of this study are to investigate the usage status of head-restraint system(H/R) in usual driving and to simulate usage conditions of H/R at rear-end crashes. The usage of H/R was categorized into five classes according to the height and distance from occupant's head ; Large-$90^{\circ}$ H/R for enough height and short distance. Large-$70^{\circ}$ H/R for enough height and long distance. Small-$90^{\circ}$ H/R for low height and short distance. Small-$70^{\circ}$ H/R for low height and long distance. and No H/R. Then. these five conditions were tested to find out the degree of neck injuries by using a car-crash simulation package, DYNAMAN. Results from the investigation of H/R usage show that most of drivers(60%) have Small-$70^{\circ}$ H/R for low height and long distance. Results from the simulation performed at 15mph and 30mph show that: 1) at 15 mph, there is a possibility for neck injury in Small-$90^{\circ}$ H/R and Small-$70^{\circ}$ H/R. 2) at 30 mph. there is a high possibility of death in Small-$70^{\circ}$ H/R and Small-$90^{\circ}$ H/R.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.3
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• pp.391-398
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• 2019

In general, truck-involved crashes increase severity in terms of both injury level and crash impact level. Recently, although the frequency and fatality of truck-involved crashes in Korea are rising, their associative studies are very limited. Therefore, the objective of this study is to identify critical factors influencing on injury severity of truck-involved crashes on Korean freeway system. To carry out this objective, this study uses an ordered probit model (OPM) based on a 6-year crash dataset from 2012 to 2017. From the analysis, eight variables were found to have a great effect on injury severity: older driver, crash speed, rear-end collision, number of vehicles involved, drowsy driving, nighttime (0:00 to 6:00) driving, overturn or rollover, and vehicle's fire after crash. However, injury severity was less severe in crashes under snowy condition and crashes to traffic facilities (i.e., crash alone).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.152-167
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• 2018

The high-speed weigh-in-motion system can collect the traveling speed and load information of individual vehicles, which can be used in a variety of ways for the traffic surveillance. However, it has a limit to apply the high-speed weigh-in-motion data directly to a safety analysis because high-speed weigh-in-motion's raw data are point measured data. In order to overcome this problem, this paper proposes a method to calculate the conflict rate and the Impulse severity based on surrogate safety measures derived from the detection time, detection speed, vehicle length, vehicle type, vehicle weight. It will be possible to analyze and evaluate the risk of rear-end collision on freeway traffic. In addition, this study is expected to be used as a fundamental for identifying crash risks and developing policies to enhance traffic safety on freeways.

• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.37-43
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• 2012

The purpose of this research is to obtain and analyze dynamic responses from human volunteers for the development of the human-like mechanical or mathematical model for Korean males in automotive rear collisions. This paper focused on the introduction to a low-speed rear impact sled test involving Korean male subjects, and the accumulation of the motion of head and neck. A total of 50 dynamic rear impact sled tests were performed with 50 human volunteers, who are 30-50 year-old males. Each subject can be involved in only one case to prevent any injury in which he was exposed to the impulse that was equivalent to a low-speed rear-end collision of cars at 5-8 km/h for change of velocity, so called, ${\Delta}V$. All subjects were examined by an orthopedist to qualify for the test through the medical check-up of their necks and low backs prior to the test. The impact device is the pendulum type, tuned to simulate the crash pulse of a real vehicle. All motions and impulses were captured and measured by motion capture systems and pressure sensors on the seat. Dynamic responses of head and T1 were analyzed in two cases(5 km/h, 8 km/h) to compare with the results in the previous studies. After the experiments, human subjects were examined to check up any change in the post medical analysis. As a result, there was no change in MRI and no injury reported. Six subjects experienced a minor stiffness on their back for no more than 2 days and got back to normal without any medical treatment.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.71-82
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• 2016

Information System for rear-end collision avoidance is a unit service of C-ITS pilot project. Road environment that the number of vehicles at the same driving high-speed has a possibility that the communication delay or failure caused by heavy load of vehicle to vehicle communication. In this study, effects of the road network about a communication failure rate of information system for rear-end collision avoidance was analyzed quantitatively with micro traffic simulation. The simulation was carried out in situation that crash of two vehicles are occurred at merging area with speed limit 80km/h and information of collision is prvoided to the rear vehicle. From simulation results, it can confirm the trend of the increasing 14% of potential conflict according to 10% increasing of the communication failure rate. C-ITS service has a goal of increasing safety. The coommunication failure rate increases due to heavy load of vehicle causes a fatal result in road safety administrator position. For the success of C-ITS project, a communication system developers side should perform the effort to reduce the communication failure rate.

• Journal of Auto-vehicle Safety Association
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• v.4 no.1
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• pp.5-11
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• 2012

This paper discusses the evaluation of the safety impact of the Adaptive Cruise Control (ACC) system in Korea. To evaluate the safety impact, this paper suggests an analysis method by using the test scenario and field operational test data. The test scenario is composed to represent the main component factor of the ACC system and ACC related accident situation such as rear-end collision, lane-change, and road-curvature, etc. Also, from the field operation test data, the system's potential to increase the safety can be measured ideally. Besides, field operational testdata was used to revise the expected safety impact value as Korean road conditions. By using the proposed evaluation method, enhanced safety impact of the ACC system can be estimated scientifically.

• 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.32 no.5
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• pp.441-451
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• 2014

This study proposes a novel performance measure, which is referred to as Hazardous Spacing Index (HSI), to be used for evaluating safety of traffic stream on freeways. The basic principle of the proposed methodology is to investigate whether drivers would have sufficient stopping sight distance (SSD) under limited visibility conditions to eliminate rear-end crash potentials at every time step. Both Road Weather Information Systems (RWIS) and Vehicle Detection Systems (VDS) data were used to derive visibility distance (VD) and SSD, respectively. Moreover, the K-Nearest Neighbors (KNN) method was adopted to predict both VD and SSD in estimating predictive HSIs, which would be used to trigger advanced warning information to encourage safer driving. The outcome of this study is also expected to be used for monitoring freeway traffic stream in terms of safety.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.78-85
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• 2021

Recently a traffic accident of heavy duty vehicles under the mandatory installation of ADAS (Advanced Driver Assistance System) is often reported in the media. Heavy duty vehicle accidents are normally occurring a high number of passenger's injury. According to report of Insurance Institute for Highway Safety, FCW (Forward Collision Warning) and AEB (Automatic Emergency Braking) were associated with a statistically significant 12% reduction in the rate of police-reportable crashes per vehicle miles traveled, and a significant 41% reduction in the rear-end crash rate of large trucks. Also many countries around the world, including Korea, are studying the effects of ADAS installation on accident reduction. Traffic accident statistics of passenger vehicle for business purpose in TMACS (Traffic safety information Management Complex System in Korea) tends to remarkably reduce the number of deaths due to the accident (2017(211), 2018(170), 2019(139)), but the number of traffic accidents (2017(8,939), 2018(9,181), 2019(10,095)) increases. In this paper, it is introduced a traffic accident case that could lead to high injury traffic accidents by being equipped with AEB in a bus. AEB reduces accidents and damage in general but malfunction of AEB could occur severe accident. Therefore, proper education is required to use AEB system, simply instead of focusing on developing and installing AEB to prevent traffic accidents. Traffic accident of AEB equipped vehicle may arise a new dispute between a driver's fault and vehicle defect. It is highly recommended to regulate an advanced event data recorder system.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.93-102
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• 2012

The frequency and severity of traffic accidents related to signalized intersections in urban areas have been more serious than those in both arterial segments and crosswalks. Especially, traffic accidents involved with injuries and fatalities have caused by traffic signal violations within intersections. Therefore, many countries including Korea have installed the red light enforcement camera (RLE) to reduce traffic accidents associated with the traffic signal violation. Meanwhile, many methodologies have been studied in terms of safety impacts estimation of red light enforcement, which, however, cannot be easy to conduct. In this study, safety impacts was estimated for intersections of Chicago downtown area using SPF models and EB approach. As a result, for all crash types and target traffic accident types such as "angle", "rear end", "sideswipe in the same and other directions", "turn", and "head on", fatal crashes were reduced by 26% and 38%. However, RLE may increase property-demage-only-crashes by 3.23% and 1.16%, respectively.