• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.5
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• pp.23-29
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• 2015

In this study, human is the subject of driving a car, the actual EEG is a biological information in a number of reactions that are displayed while driving the vehicle by using a measuring device, occurs during travel of the road EEG to be collected, number of experiments the collected material on the basis of changes associated with running time, extracts the factors such as changes due to road geometry, and analysis was performed. The required changes in the EEG occurring during traveling experiment analysis alpha (${\alpha}$) waves, beta (${\beta}$) wave, after the primary extraction in the form of gamma (${\gamma}$) faction, the brain wave frequency of the entire period of the experiment change rate extracts, to calculate the change in frequency in response to EEG characteristics by applying the regression model to observe a learning effect in response to an increase in the number of experiments, as a result, depending on the number of experiments, EEG changes due to individual differences. The show, by repeatedly driving a section like this, it was possible to verify that comfortably travels driver accustomed in accordance with the stored road geometry and signal, safety facilities.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.59-64
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• 2008

The urban is possessing of various landuses such as commercial, industrial, residential and official areas. All of these landuses is including the paved areas that are roads and parking lots. The NPS (nonpoint sources) pollutants are generally originated from pavement areas in urban by human activities. Especially the roads are stormwater intensive landuses because of high vehicle activities and high imperviousness. The main NPS pollutants from roads are particulates and metals from vehicles and pavements. The Korea MOE (Ministry of Environment) is developing the NPS control program to reduce the NPS pollutants from the basins. However, it is not easy to control the NPS because it has high uncertainty by characteristics of rainfalls and watersheds. Therefore, this research was conducted on characterizing the runoff and providing mean EMC from roads. The monitoring were performed for total 16 rainfall events from a road in Youngin City since 2006. The results show that the TSS is highly correlated with other pollutant parameters. The statistical regression models using TSS EMC have been developed to easily determine the EMC of other pollutant parameters.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.95-105
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• 2009

Traffic accidents on highways are likely to happen when there is an imbalance in the complex relationships among key elements such as road geometries, driver related factors, and mechanical performances. The Demand-Effort Model (DEM), which evaluates highway safety, can be explained by the imbalance, which occurs when the level of demand of the driver's attention to the road environment exceeds that of the response from the driver. This study suggests a new model that improves the reliability of the current DEM through the reinterpretation on the physiological signals with the help of the Neural Network Model (NNM). The data were collected from 149 subjects, who drove a test vehicle on the Yongdong, Honam, and Seohaean Expressways in Korea. Three important results could be drawn from the recursive tests as follows; (1) Only 5 out of 10 parameters on the physiological signals which are currently used were proven to be meaningful through the Normality Test, Cluster Analysis, and Mann-Whitney Analysis. (2) The revised DEM, which internally uses the NNM, showed more reliable results than existing DEM. Group 1, which is based on the new DEM showed 80.0% of accuracy in measuring the level of driver's efforts, however, that of Group 2 based on the current DEM was 74.3%. (3) Field tests on the Honam Expressway showed lower 'type II error' with the new DEM (40.5%) than the old DEM (58.8%). The DEM is designed as a quick and easy way to determine highway safety prior to the minute road safety audit (RSA) by a professional audit team. Then a new DEM, which is based on the NNM, needs to be considered since it showed higher reliability and lower error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.175-181
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• 2020

This paper suggests a proper hydraulic filling method in downtown areas. Road subsidence on roadways and sidewalks in downtown areas can result in vehicle damage and casualties. The representative cause of road subsidence is the fraudulent construction in nearby construction sites. A deficiency of excavation restoration causes approximately 25~49% of subsidence. This is performed by equipment or manpower. Hydraulic filling is used in backfilling narrow pipe conduits and spaces between structures. On the other hand, standard specifications and quality assurance standards regarding hydraulic filling principles and construction conditions are insufficient. Therefore, in-door model experiments on hydraulic filling principles, backfilling material, and compaction efficiency were performed. This paper suggests guidelines by investigating and analyzing construction status. In conclusion, thrown backfilling material has a particle size distribution and permeability coefficient as major factors, and detailed standards of the factors are suggested. To improve the compaction efficiency, 90% or more, compaction by the floor should be in units of 0.3m while ensuring a lower drainage layer. When an H-shape stabilizing pile is pulled out after filling, additional hydraulic filling should be in the disturbance range.

• 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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.12-19
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• 2010

In road network, especially in urban area, inefficiency of travel time is caused by signal control and turn maneuver at intersection and this inefficiency has substantial effects on travel time. When searching for the shortest path, this inefficiency which is caused by turn maneuver must be considered. Therefore, travel time, vehicle volume and delay for each link were calculated by using simulation package, PARAMICS V5.2 for adaptation of turn penalty at 16 intersections of Gangnam-gu. Turn penalty was calculated respectively for each intersection. Within the same intersection, turn penalty differs by each approaching road and turn direction so the delay was calculated for each approaching road and turn direction. Shortest path dealing with 16 intersections searched by Dijkstra algorithm using travel time as cost, considering random turn penalty, and algorithm considering calculated turn penalty was compared and analyzed. The result shows that by considering turn penalty searching the shortest path can decrease the travel time can be decreased. Also, searching the shortest path which considers turn penalty can represent reality appropriately and the shortest path considering turn penalty can be utilized as an alternative.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.69-76
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• 2018

PURPOSES : This study determined the optimal usage rate of RAP (reclaimed asphalt pavement) using cold central-plant recycling (CCPR) on a road-surface layer. In addition, a mixture-aggregate gradation design and a curing method based on the proposed rate for the surface-layer mix design were proposed. METHODS : First, current research trends were investigated by analyzing the optimum moisture content, mix design, and quality standards for surface layers in Korea and abroad. To analyze the aggregate characteristics of the RAP, its aggregate-size characteristics were analyzed through the combustion asphalt content test and the aggregate sieve analysis test. Moreover, aggregate-segregation experiments were performed to examine the possibility of RAP aggregate segregation from field compaction and vehicle traffic. After confirming the RAP quality standards, coarse aggregate and fine aggregate, aggregate-gradation design and quality tests were conducted for mixtures with 40% and 50% RAP usage. The optimum moisture content of the surface-layer mixture containing RAP was tested, as was the evapotranspiration effect on the surface-layer mixture of the optimum moisture content. RESULTS : After analyzing the RAP recycled aggregate size and extraction aggregate size, 13-8mm aggregate was found to be mostly 8mm aggregate after combustion. After using surface-chipping and mixing methods to examine the possibility of RAP aggregate segregation, it was found that the mixing method contributed very little for 3.32%, and because the surface-chipping method applied compaction energy directly as the maximum assumption the separation ratio was 15.46%. However, the composite aggregate gradation did not change. Using a 40% RAP aggregate rate on the surface-layer mixture for cold central-plant recycling satisfied the Abroad quality standard. The optimum moisture content of the surface-layer mixture was found to be 7.9% using the modified Marshall compaction test. It was found that the mixture was over 90% cured after curing at $60^{\circ}C$ for two days. CONCLUSIONS : To use the cold central-plant recycling mixture on a road-surface layer, a mixture-aggregate gradation design was proposed as the RAP recycled aggregate size without considering aggregate segregation, and the RAP optimal usage rate was 40%. In addition, the modified Marshall compaction test was used to determine the optimum moisture content as a mix-design parameter, and the curing method was adapted using the method recommended by Asphalt Recycling & Reclaiming Association (ARRA).

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.11-24
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• 2017

Although many efforts to stop speeding or inappropriate speed, it failed to reduce the number of speeding-related crashes. Therefore, it is important to analyze the characteristics of speeding offenders and the cause of speeding at hot spots. In this study, we investigate the level of severity in speeding by the characteristics of speeding offenders using the Ordered Logistics Regression Models(OLRM). For the analysis, we use the speeding data collected by 39 traffic enforcement cameras in city of Cheongju and other related data including the speeding ticket history of drivers during the most recent 3 years, their demographic characteristics, their own vehicles, and road environment factors. The major results of this study are as follows. Firstly, commercial fleet drivers are more likely to repeat the conviction of high-range speeding with more than 30km/h over speed limits than other drivers. Secondly, mid-range speeding are observed as 21,462 frequency which is 76.7% of total speeding frequency and occurred mostly at suburban and rural area. It concludes that contributory factors affecting the severity of speeding at signalized intersection are drivers' speeding offence history, posted speed limits, time of day, gender of driver, and location of the intersection as show by the OLRM developed in this study(McFadden R-square : 0.296).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.96-106
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• 2014

Necessarily traffic policies have been biased in car than pedestrian, so pedestrian's environment is getting worse. Result of this situation our accident rate is high as 36.4%, compared to OECD member countries with average rate of 17.8%(in 2009). Increasing interest for pedestrians environment improvement, and it make an effort to build environment to guarantee walk and safety of pedestrians. Analysis on the binary logistic regression(BLR) was used. The dependent variable is occurring from the road width of less than 9m accident, and independent variable extracted can be obtained from the traffic accident data. Traffic accident on roads having width of less than 9 meters affecting variables is when the driver is straight, when the driver is female, when the pedestrian is walk driveway, and so on. To prevent it, efforts is demanded to protect handicapped, to build safe pedestrians environment using C-ITS and to decrease speed of going straight vehicle on roads having width of less than 9 meters.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.40-49
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• 2017

The purpose of the research is to analyze the recent cases of green space planning and planting design in Beijing, one of the cities having the worst particulate matters (PM) pollution. This study comprehensively reviewed Chinese academic literature addressing green space planning to reduce PM pollution. In addition, we conducted field observations and interviews with public officials from Beijing Municipal Bureau of Landscape Design in charge of planning and management of green spaces in Beijing. After the extensive review of literature we derived tree planting principles to mitigate the impact of PM from urban road system, residential area, and industrial district. Using the principles we evaluated the three recent cases of planting design to mitigate PM: Beijing Fuxing Road, Fu Run Residential Area and Beijing Beiqi Multipurpose Vehicle Factory. We conclude that green space planning and trees planting are not effective in mitigating negative impact of PM pollution because of inadequate selection of trees and inconsiderate planting composition. We proposed to replace the tree species with the ones capable of reducing the spread of PM, and reorganize planting compositions that consider the directions and characteristics of urban wind flow. This study suggests desirable types of tree species and planting compositions for road, residential and industrial districts, and we expect that it provides helpful guidelines for making planting design and species selection to mitigate the impact of PM in urban landscape.