• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1525-1534
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• 2014

In recent years, the passengers are likely to decide their route on impulse due to the development of the integrated public transport system, and real-time information system. Especially, public transport fare integration in Seoul Metropolitan area, 2004 makes them not to have resistance about changing the modes or routes and their route choice is most effected by the degree of congestion. Assignment model have limitations to describe route changes by congestion. In this study, the concept of a link cost function used in road assignment and Effective frequency is introduced to describe the passengers' behavior when the capacity of public transport is over and the waiting time variation. Two situations, new transit line operation and accident, are set up to validate the model, as a result of the transit assignment by this model, the traffic on networks is not over the capacity. It is expected that this study will be of help to reflect the various behaviors in transit assignments.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.5
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• pp.571-580
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• 2012

Epidemiologic studies of air pollution need accurate exposure assessments at unmonitored locations. A land use regression (LUR) model has been used successfully for predicting traffic-related pollutants, although its application has been limited to Europe, North America, and a few Asian region. Therefore, we modeled traffic-related pollutants by LUR then examined whether LUR models could be constructed using a regulatory monitoring network in Metropolitan area in Korea. We used the annual-mean nitrogen dioxide ($NO_2$) in 2010 in the study area. Geographic variables that are considered to predict traffic-related pollutants were classified into four groups: road type, traffic intensity, land use, and elevation. Using geographical variables, we then constructed a model to predict the monitored levels of $NO_2$. The mean concentration of $NO_2$ was 30.71 ppb (standard deviation of 5.95) respectively. The final regression model for the $NO_2$ concentration included five independent variables. The LUR models resulted in $R^2$ of 0.59. The mean concentration of $NO_2$ of elementary schools was 34.04 ppb (standard deviation of 5.22) respectively. The present study showed that even if we used regulatory monitoring air quality data, we could estimate $NO_2$ moderately well. These analyses confirm the validity of land use regression modeling to assign exposures in epidemiological studies, and these models may be useful tools for assessing health effects of long-term exposure to traffic related pollution.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.32-45
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• 2018

This study aims to compare the mutual perception gap on dangerous driving behavior between male and female drivers in multiple aspects, analyze them, and identify factors that trigger this different perception. To understand the mutual perception gap on dangerous driving behavior, DBQ(Driving Behavior Questionnaire) was applied as a rating scale. By applying results into the Co-oreintation model, this study compared the mutual perception gap between male drivers and female drivers and analyze results. In addition, factors that generate the perception gap between both genders were drawn by analyzing factors. This study suggested that objective consistency identified the perception gap that driving behaviors of others were more dangerous between two genders. In addition, subjective consistency was different as both genders assumed that the counterpart's driving behavior takes more risks than their own actual driving behaviors. In regard to the accuracy, men were aware that female driving behaviors are more dangerous than their behaviors. However, female driving behavior assumed by women was consistent with male perception in all factors, which indicated that women perceive men precisely. In addition, results were compared and analyzed in both perspectives of male drivers and female drivers by combining predictive models. Based on these results, both genders perceived that counterpart's driving behavior is more dangerous among both genders.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.103-113
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• 2005

A pedestrian accident is generally less fully understood than the 'typical' car-to-car collision. For this reason, the analysis of the pedestrian accident is, in many respects, more complicated and demanding. The purpose of this study is to identify clearly the impact point that is the main subject of struggle in pedestrian accidents. In order to develop the model, it is very significant to classify actual accident data including impact velocity. vehicle damage and injury scale of pedestrian. These data were collected from three local branches of RTSA(Road Traffic Safely Authority). The number of collected data were 34 cases and 61.7% of them were fatal accidents. In consequence of analyzing the data by statistical method, it revealed that there is correlation between impact velocity and throw distance. It, also shows that the impact velocity has strong linear correlation to vehicle damage and injury scale. Consequently, reconstruction analysis models of pedestrian accidents considering in local circumstances(such as the physical characteristics of pedestrians and vehicles) was developed However. it is difficult to apply the result of this study to all sorts of pedestrian accidents, because the actual accident data which were used to develop the model were limited. To overcome this limitation, it is necessary to develop an analysis model applicable to diverse circumstances with a wide range of pedestrian accident data on a national basis.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.195-203
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• 2009

This research wished to risk type and examine closely driver special quality and relation of traffic accidents by occurrence type of traffic accidents and traffic accidents seriousness examine closely relation with Severity. Fractionate traffic accidents type by eight, and driver's special quality for risk group's classification did to distinction of sex, vehicle type, age etc. analyzed relation with injury degree adding belt used putting on availability for security the objectivity with wave. Used log-Linear model and Logit model for analysis of category data. A head-on collision and overtaking accident, right-turn accident are high injury or death accident and possibility to associate in relation with accident type and seriousness degree. In risk group analysis The age less than 20 years in motor-cycle driver, taxi driver in 41 years to 50 years old are very dangerous. The woman also was construed to the more risk group than man from when related to car, mini-bus, goods vehicle etc. Therefore, traffic safety education and Enforcement for risk group that way that can reduce accident that produce to reduce a loss of lives at traffic accidents appearance a head-on collision and overtaking accidents, right-turn accidents should be studied and as traffic accidents weakness class may have to be solidified.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.211-218
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• 2010

Volume of concrete slab changes by temperature and moisture effects. At that time, tensile stress develops because the slab volume change is restrained by friction resistance between the slab and subbase, and then crack occurs occasionally. Accordingly, researchers have made efforts to figure out the friction characteristics between the slab and subbase by performing push-off tests. Lately, researches to analyze concrete pavement behavior by the friction characteristics have been performed by finite element method. In this study, The friction characteristics between the slab and subbase were investigated based on the friction test results for lean concrete, aggregate, and asphalt subase widely used in Korean concrete pavements. The energy method bilinearizing relation between nonlinear friction resistance and displacement were suggested. The friction test was modeled by 3-D finite element program, ABAQUS, and the model was verified by comparing the analyzed results to the test results. The bilinear model developed by the energy method was validated by comparing analysis results obtained by using the nonlinear and bilinear friction resistance displacement relation as input data. A typical Korean concrete pavement was modeled by ABAQUS and EverFE and analyzed results were compared to evaluate applicability of the bilinear model.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.147-158
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• 2010

Studies on the distribution of traffic demands have been proceeding by providing traffic information for reducing greenhouse gases and reinforcing the road's competitiveness in the transport section, however, since it is preferentially required the extensive studies on the driver's behavior changing routes and its influence factors, this study has been developed a discriminant model for changing routes considering driving conditions including traffic conditions of roads and driver's preferences for information media. It is divided into three groups depending on driving conditions in group classification with the CART analysis, which is statistically meaningful. And, elements of the driving conditions and the preferred media affecting the change of paths are classified into statistical meaningful groups through the CHAID analysis, and the major factors affecting the change of paths are examined. Finally, the extent that driving conditions and preferred media affect a route change is examined through a discriminant analysis, and it is developed a discriminant model equation to predict a route change. As a result of building the discriminant model equation, it is shown that driving conditions affect a route change much more, the entire discriminant hit ratio is derived as 64.2%, and this discriminant equation shows high discriminant ability more than a certain degree.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.169-183
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• 2010

Image-based traffic information collection systems have entered widespread adoption and use in many countries since these systems are not only capable of replacing existing loop-based detectors which have limitations in management and administration, but are also capable of providing and managing a wide variety of traffic related information. In addition, these systems are expanding rapidly in terms of purpose and scope of use. Currently, the utilization of image processing technology in the field of traffic accident management is limited to installing surveillance cameras on locations where traffic accidents are expected to occur and digitalizing of recorded data. Accurately recording the sequence of situations around a traffic accident in a freeway and then objectively and clearly analyzing how such accident occurred is more urgent and important than anything else in resolving a traffic accident. Therefore, in this research, existing technologies, this freeway attribute, velocity changes, volume changes, occupancy changes reflect judge the primary. Furthermore, We pointed out by many past researches while presenting and implementing an active and environmentally adaptive methodology capable of effectively reducing false detection situations which frequently occur even with the Gaussian Mixture model analytical method which has been considered the best among well-known environmental obstacle reduction methods. Therefore, in this way, the accident was the final decision. Also, environmental factors occur frequently, and with the index finger situations, effectively reducing that can actively and environmentally adaptive techniques through accident final judgment. This implementation of the evaluate performance of the experiment road of 12 incidents in simulated and the jang-hang IC's real-time accident experiment. As a result, the do well detection 93.33%, false alarm 6.7% as showed high reliability.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.2
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• pp.10-16
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• 2000

The purpose of this study is to identify relationships between a central angle and a radius of curvature of divided roads in flat terrain of traditional villages, suggesting layout criteria for traditional villages: Nak-an, Sung-Eup, Ha-Whe. This study is sought to find the optimum model through the various SAS regression analyses. a regression analysis of this data was adopted to induce the relationship formula between a central angle of curve and a radius of curvature. Results of this study are as follows: 1) Most of the divided roads in traditional villages have a complex curve rather than a simple curve. 2) A central angle of curve has ranged from 11$^{\circ}$to 127$^{\circ}$, with a mean degree of 63.9. 3) In the lower level of central angle(11-40$^{\circ}$), the branch roads have distributed with a high frequency, but with a low frequency in the higher level of central angle(90-140$^{\circ}$). 4) A radius of curvature in the divided roads has ranged from 0.9m to 59.6, but half of the roads have concentrated on 1-6m of the curvature. 5) Compared to the result of hilly villages in previous study(Ahn, 1999), value of central angels in flat villages is lower than that of hilly villages, while a mean value of the curvature is higher than that of hilly villages. 6) A Non-linear regression analysis, resulting from the SAS application, was useful method to induce a relationship formula between a central angle and a radius of curvature in the branch roads. Our study's formula is as follow: R=100.3*EXP(-0.06*$\delta$)+3.91. 7) Our study model has less error than that of the Kishizuka's method, being applicable to a broader range of the branch roads. 8) A minimum radius of curvature in our study has showed 3.9m, suggesting to reconsider applications of the Kishizuka's(5.8m) in the footpass design, In the study for this presupposition model the efficiency and utility of it can be estimated to grow large according to how much and how far it includes both extremes of data. This study is for the application to a design in future through the numerical formula of divided roads of various traditional villages. The studies from now on will be about the quasi-hilly quasi-hilly village and hilly village supplementing these factors more.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.227-241
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• 2005

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.