• International Journal of Highway Engineering
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• v.15 no.4
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• pp.135-146
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• 2013

PURPOSES : This study aimed to analyze the impact the operation of pre-signals at 4-leg signalized intersections and present primary environmental factors of roads that need to be considered in the installation of pre-signals. METHODS : Shift of proportions safety effectiveness evaluation method which assesses shifts in proportions of target collision types to determine safety effectiveness was applied to analyze traffic crash by types. Also, Empirical Bayes before/after safety effectiveness evaluation method was adapted to analyze the impact pre-signal installation. Negative binomial regression was conducted to determine SPF(safety performance function). RESULTS : Pre-signals are effective in reducing the number of head on, right angle and sideswipe collisions and both the total number of personal injury crashes and severe crashes. Also, it is deemed that each factor used as an independent variable for the SPF model has strong correlation with the total number of personal injury crashes and severe crashes, and impacts general traffic crashes as a whole. CONCLUSIONS: This study suggests the following should be considered in pre-signal installation on intersections. 1) U-turns allowed in the front and rear 2) A high number of roads that connect to the intersection 3) Many right-turn traffic flows 4) Crosswalks installed in the front and rear 5) Insufficient left-turn lanes compared to left-turn traffic flows or no left-turn-only lane.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.198-206
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• 2014

According to the statistics of the National Police Agency, red light running (RLR) crashes represent a significant safety issue throughout Korea. This study deals with the RLR crashes occurred at signalized intersections in Cheongju. The objectives of this study are to comparatively analyze the characteristics of between RLR crashes and the Non-RLR crashes, and to find out factors using a Binary Logistic Regression(BLR) model. In pursuing the above, the study gives particular attentions to testing the differences between the above two groups with the data of 2,246 RLR/ 3,884 Non-RLR crashes (2007-2011). The main results are as follows. First, many RLR crashes were occurred in the nighttime and in going straight. Second, the difference between RLR and Non-RLR crashes were clearly defined by crash type, maneuver of vehicle before crash, age of driver (30s, 50s), alcohol use and accident pattern. Finally, a statistically significant model (Hosmer and Lemeshow test : 7.052, p-value : 0.531) was developed through the BLR model.

• Safety and Health at Work
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• v.10 no.2
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• pp.213-218
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• 2019

Background: Motorcycles are one of the important members of commercial transportation because of the convenient use during congested traffic conditions and the ease of parking in narrow streets. This study investigates the characteristics of crashes and traffic signal violations caused by motorcycle couriers. Methods: From the national compensation data, this study analyzed the traffic crashes caused by 671 motorcycle couriers. Results: Among 671 injured couriers, 50.6% were aged less than 40 years, 49.2% run in a small business of <5 employees, and 47.2% had work experience of <6 months. Motorcycle crashes occurred mainly due to "rider overturned alone" (67.5%), in the daytime (73.5%), or on cloudy or clear days (77.2%). However, the violation rate caused by motorcycle couriers was high in couriers in a small business of <5 employees (13.9%), with work experience of <6 months (13.9%), on cloudy or clear days (12.4%), on an intersection (29.8%), in the type of "crash with a vehicle" (31.2%), or in a death accident (35.7%) Conclusion: The findings of this study can be used as a baseline in devising policies for preventing crashes of motorcycle couriers.

• Journal of Korean Society of Transportation
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• v.34 no.2
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• pp.123-134
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• 2016

Traffic accident at intersections takes 44.3% of total number of accidents on entire road network of Korea in 2014. Although several studies addressed contributory factors of accidents at signalized intersection, very few is known about the factors at rural unsignalized intersections. The objective of this study is therefore to investigate specific characteristics of crashes at rural unsignalized intersection and to identify contributory factors in causing crashes by statistical approach using the Ordered Logistic Regression Model. The results show that main type of car crashes at unsignalized intersection during the daytime is T-bone crashes and the number of crashes at 4-legged intersections are 1.53 times more than that at 3-legged intersections. Most collisions are caused by negligence of drivers and violation of Right of Way. Based upon the analysis, accident severity is modeled as classified by two types such as 3-legged intersection and 4-legged intersection. It shows that contributory factors in causing crashes at rural unsignalized intersections are poor sight distance problem, average daily traffic, time of day(night, or day), angle of intersection, ratio of heavy vehicles, number of traffic violations at intersection, and number of lanes on minor street.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.90-97
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• 2009

One of the most important factors that affect a person's risk of injury in a motor vehicle crash is the age of the person. This study investigates the characteristics of crash injuries among young, middle-aged and older drivers and occupants. Based on the comprehensive claim data from automobile insurance from 2000 to 2007, this study examines in great detail the drivers and occupants injury body regions and severity by age in car-to-car frontal crashes. It has been shown that elderly drivers and occupants suffer more injuries at a chest region compared to the middle-aged group. This research calls attention to the need for design to make vehicles more protective for older drivers in car-to car frontal crashes.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.84-87
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• 2003

Drowsy driving is a major cause of automobile crashes and can lead to more serious injuries than other causes of traffic accidents. Factors increasing the risk of drowsy driving and related crashes include sleep loss, late night driving, untreated or unrecognized sleep disorders, use of sedating medications and consumption of alcohol. Young people, especially young males, shift workers, and people with untreated sleep apnea syndrome and narcolepsy are well known as the population groups at highest risk. To prevent drowsy driving and its consequences, getting adequate and quality sleep is both easier and much more successful than any remedial measure. Other helpful behaviors include avoidance of alcoholic beverages and limiting late night driving. Taking a short nap or consuming caffeine can make a short-term difference in driving alertness. In addition, information should be actively provided to the public about the importance of sleep disorders and their consequences. To reduce injuries and death caused by drowsy driving, it is a prerequisite to increase public awareness that drowsy driving can cause serious automobile crashes and has morbidity and mortality rates as high as those of drunk driving.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.453-459
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• 2010

In the study of traffic safety, it is utmost important to obtain more reliable estimates of the expected crashes for a site (or a segment). The observed crashes have been mainly used as the estimate of the expected crashes in Korea, while the empirical Bayes (EB) estimates based on the Poisson-gamma mixture model have been used in the USA and several European countries. Although numerous studies have used the EB method for estimating the expected crashes and/or the effectiveness of the safety countermeasures, no past studies examine the difference in the estimation errors between the two estimates. Thus, this study compares the estimation errors of the two estimates using a Monte Carlo simulation study. By analyzing the crash dataset at 3,000,000 simulated sites, this study reveals that the estimation errors of the EB estimates are always less than those of the observed crashes. Hence, it is imperative to incorporate the EB method into the traffic safety research guideline in Korea. However, the results show that the differences in the estimation errors between the two estimates decrease as the uncertainty of the prior distribution increases. Consequently, it is recommended that the EB method be used with reliable hyper-parameter estimates after conducting a comprehensive examination on the estimated negative binomial model.

• International Journal of Highway Engineering
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• v.19 no.6
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• pp.201-212
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• 2017

PURPOSES : The objective of this study is to identify the characteristics affecting traffic accidents that have occurred in 564 industrial complexes nationwide from 2011 to 2015. METHODS : The traffic accidents were specified using various factors such as industrial complex type (national VS. general), industrial complex degradation (old VS. non-old), location of complex (capital VS. non-capital), and traffic law violation (speeding, signal violation, and median invasion). The average number of crashes and accident ratio (fatal, severe, and both) in terms of characteristics of industrial complexes were calculated. With a sample of crashes of the industrial complexes for 5 years, statistical significances were tested to analyze and compare the differences based on industrial complex and traffic law characteristics using parametric and non-parametric methods. RESULTS : From statistical results, it is observed that the crash frequency occurring in old industrial complexes is three times higher than that in non-old industrial complexes. Old industrial complexes located in a capital area, old national industrial complexes, and old general industrial complexes are considerably related to higher crash frequency, but the fatal accident ratio appeared to have no statistical difference across industrial complex characteristics. Severe crashes are more likely to occur in non-old industrial complexes on an average. CONCLUSIONS : It is necessary to eliminate potential threats to roads and traffic in the same manner as illegal parking in industrial complexes through the restoration of old industrial complexes. To improve the efficiency of road infrastructure, efforts should be made to improve traffic safety in accordance with industrial characteristics such as planning and operation of relevant local government programs.

• International Journal of Highway Engineering
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• v.9 no.2 s.32
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• pp.77-87
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• 2007

Traffic accidents on freeway are occurred by various factors, and driver inattention is one of the most important factors causing traffic accidents. To warn drivers about unexpected dangerous events and diminish driver inattention problems, traffic safety facilities including warning and regulatory traffic signs; delineators; rumble strips are installed. In this study, the traffic safety effect of shoulder rumble sips were investigated using "Comparison Croup (C-G)" method developed by Hauer. Through the analyses, it was found that numbers of run-off-the road crashes were reduced as 2.43 crashes per year after the installation of shoulder rumble strips on the freeway. Based on the analysis results in this study, it was concluded that shoulder rumble strips on the freeway contribute to reduce traffic accidents, especially run-off-the road crashes.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.63-72
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• 2012

While the number of crashes and fatalities has decreased for the last few decades, the proportion of elderly-involved crashes has continuously increased from 19.5% in 2001 to 29.6% in 2008. This paper aims to evaluate the effectiveness of traffic safety education to seniors, which has been conducted for the purpose of providing more systematic knowledge such as safety regulations and making the elderly more aware of the risks of crashes, and eventually to reduce elderly-involved crashes. First, we investigated the levels of traffic safety knowledge of the elder people who attend senior community centers and social welfare centers in Seoul and provided traffic safety education. Then, the effectiveness of traffic safety education was evaluated by using the before-and-after analysis. We set up two different groups to improve the reliability of evaluation: one for control group and the other for comparison group. The results showed that the average scores of the control group after education were significantly improved at the 95% significance level compared to the average scores before education, whereas the comparison group did not show a significant differences in the average scores before and after education except for two questions. This indicates that the levels of traffic safety knowledge of the control group have been improved through education and therefore, the safety education seem to be effective to some extent.