• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.108-117
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• 2011

Seoul metropolitan government has been operating traffic signal control system with the name of COSMOS since 2001. COSMOS uses the degrees of saturation and congestion which are calculated by installing loop detectors. At present, inductive loop detector is generally used for detecting vehicles but it is inconvenient and costly for maintenance since it is buried on the road. In addition, the estimated queue length might be influenced in case of error occurred in measuring speed, because it only uses the speed of vehicles passing by the detector. A traffic signal control algorithm which enables smooth traffic flow at intersection is proposed. The proposed algorithm assigns vehicles to the group of each lane and calculates traffic volume and congestion degree using traffic information of each group using VANETs(Vehicular Ad-hoc Networks) inter-vehicle communication. It does not demand additional devices installation such as cameras, sensors or image processing units. In this paper, the algorithm we suggest is verified for AJWT(Average Junction Waiting Time) and TQL(Total Queue Length) under single intersection model based on GLD(Green Light District) Simulator. And the result is better than Random control method and Best first control method. In case real-time control method with VANETs is generalized, this research that suggests the technology of traffic control in signalized intersections using wireless communication will be highly useful.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.560-569
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• 2019

Purpose: Greenhouse gases are one of the major causes of global warming, a global disaster. This study aims to calculate road sector greenhouse gas emissions more precisely than conventional methods. Method: Currently, the average speed of a vehicle is used to calculate greenhouse gas emissions. In this study, GHG emissions are calculated using the speed of individual vehicles and compared with current methods. Result: It was confirmed that the existing emission estimation method underestimated about 15% in the case of carbon dioxide, about 1% in the case of nitrous oxide, and about 1% in the case of methane. Conclusion: Current methods of estimating greenhouse gas emissions were developed before 2000 and were developed to meet the limits of available data. However, with the advancement of technology, the quality of available data is now high, and new emissions estimation methods are needed. Therefore, in this study, we propose a method for estimating the velocity-based greenhouse gas emissions of individual vehicles as a more accurate method for calculating greenhouse gas emissions.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.548-559
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• 2019

Purpose: Analysis method of V2I data driven motorway service area usage behavior to cope with manpower survey. Method: Segmentation of traveling state group and boundary using the distribution characteristics of traveling speed data of individual vehicles. Result: As a result of the verification, the use rate of resting places in lunchtime surged, and the boundary between the distribution status of the traffic speed data was clearly or unclear. Conclusion: The effect of the cost reduction is big because it can cope with the use of rest area survey by manpower and there is no limit in the time and space range of investigation. The dynamic utilization rate of each time sequence, such as a service area/drowsiness shelter/simple service area, with a V2I system, can be calculated. Identify illegal parking on highway section. Identify the unexpected situation in the road section. Identify the real-time service area utilization rate and congestion information.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.131-137
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• 2010

The stormwater runoff from rest areas in highways are known as more polluted compared to highways because of more vehicle activities. This study is performed to find pollutant characteristics in the rest areas in the magnitude of statistical pollutant concentrations during storms. Washoff characteristics of pollutants from rest areas by monitoring of rainfall, runoff rate and runoff samples were evaluated. High concentrations of pollutants in runoff were observed at the beginning of runoff and rapid decrease thereafter, indicating that first-flush effects are clearly occurred. Event Mean Concentrations(EMCs) of TSS, COD, TN, and TP are estimated to be in the range of 31.04-127.11mg/L, 35.5-369.5mg/L, 2.62-9.86 mg/L, and 0.53-1.96mg/L, respectively. Heavy metals in runoff showed relatively high values, possibly due to the abrasion of brake pad or tire while cars are slowly moving for parking. EMCs of total Pb, total Cu, and total Ni are in the range of $1206-16293{\mu}g/L$, $237-7906{\mu}g/L$, and $53-6372{\mu}g/L$, respectively. Pollutant loading per rest area calculated by using EMC, flowrate and target area is also described for each pollutant.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.89-99
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• 2004

The purpose of this study is to evaluate the value of information on Bus-Route concerning on the User's Individual value. The value of information is estimated with the price of time saving by using the information. The price of unit time for each user is applied to convert the saving time to the cost. To estimate the user's expense from origin to destination the previous model is modified. Bus-travel cost is estimated with variables such as bus-travel time, bus-interval, bus-fare, and the price of walking distance. In this study, to estimate in-vehicle time the bus-travel time model is developed based on the spatial characteristics distinguished by three types of circular-road in the network of Daegu Metropolitan area. For the case study, a set of the origin and destination is selected as Dalsu-gu District Office and East Daegu Train Station respectively. There are several bus-routes which can be used as direct or transferable bus-routes selected. The study showed that when the value of time for individual users is \1,738/hr, there is no benefit to using information of transferable bus-routes. It also showed that the more discount rates of bus fare is increased, the benefit to using information of transferable bus-routes is increased, and that the lower value of time is, the benefit to using information of transferable bus-routes is increased.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.207-218
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• 2001

As a city and industries are developed rapidly, a traffic accident and congestion take places on the road link become serious and it can be a large problem of the society in the future. Especially, most of the traffic accidents on the signalized intersection are caused by the human factor, vehicle and environmental factor mutually. The relation of the traffic accident and volume is acting on the outbreak of the traffic accident and the mistake of driver altogether as a major cause. The purpose of this paper is to develop a model for the forecasting of the traffic accident and to use research data gained to predict many traffic accidents. The data of this study were used with real one of the 73 areas of the four-legged signalized intersection in Kwang-ju city from 1996 to 1998 for three years to develop a model for the forecasting of the traffic accident. The statistical methods used in this paper are the principal component, regression and correlation analysis. We studied accident models to find out useful data from the statistics method and applied the data to the different area of the Choun-La province for the verification of the model. So, the result of this paper showed a reasonable model for the forecasting or the traffic accident and possibility of the model for simulating on real case. Finally, This study would be made of a study continually for the safe design and plan for the four-legged signalized intersection.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.43-52
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• 2012

A lane departure warning system (LDWS) is an effective technology-based countermeasure for preventing traffic crashes as it provides warning information to drivers. Understanding the characteristics of perception and satisfaction levels on LDWS is fundamental for deriving better performance and functionality enhancements of the system. The purpose of this study is to evaluate the user satisfaction of LDWS. A survey to collect user perception and user preference data was conducted. Both cross-tabulation analysis and binary logistic regression technique were adopted to identify the factors affecting user satisfaction for LDWS. The results revealed that the accuracy and timeliness of warning information was significant for evaluating the effectiveness of LDWS. In particular, the warning accuracy at a curve segment on the road was the most dominant factor affecting user satisfaction. The outcome of this study would be valuable in evaluating and designing LDWS functionalities.

• Journal of Korean Society of Transportation
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• v.34 no.4
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• pp.341-353
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• 2016

Highway is mainly in charge of middle-long distance of vehicular travel. Trip length has shown a growing trend due to increased commute distances by the relocation of public agencies. For this reason, the proportion of driver-driven accidents, caused by their fatigue or sleepiness, are very high on highways. However, existing studies related to accident prediction have mainly considered external factors, such as road conditions, environmental factors and vehicle factors, without driving behavior. In this study, we suggested an accident index (FDR, Fatigued Driving Rate) based on traffic behavior using large-scale Car Navigation path data, and exlpored the relationship between FDR and traffic accidents. As a result, FDR and traffic accidents showed a high correlation. This confirmed the need for a paradigm shift (from facilities to travel behavior) in traffic accident prediction studies. FDR proposed in this study will be utilized in a variety of fields. For example, in providing information to prevent traffic accidents (sleepiness, reckless driving, etc) in advance, utilization of core technologies in highway safety diagnostics, selection of priority location of rest areas and shelter, and selection of attraction methods (rumble strips, grooving) for attention for fatigued sections.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.153-164
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• 2009

This Paper presents the severity analysis result of the year 2006 national pedestrian crashes using the data base of 37,589 records prepared for the National Police Bureau. A set of attributing factors considered to affect pedestrian crash patterns were selected, and their contributing effects were investigated by applying the Ordered Logit Model. This model was selected because this model has been able to afford satisfactory results when the dependent variable involved ordered severity levels; fatal, injury, and property- damage-only in this investigation. The investigation has unveiled the followings; First, the pedestrian crash patterns were dependent upon human -drivel and pedestrian- characteristics including gender, age, and drinking conditions. Second, other contributing factors included vehicle, roadway geometric, weather, and hour of day characteristics. Third, seasonal effect was not contributive to crash patterns. Finally, the application of the Ordered Logit Model facilitated the ordered severity level analysis of the pedestrian crash data. This paper concludes that conventional wisdom on the pedestrian crash characteristics is largely truthful. However, this conclusion is limited only to the data used in this analysis, and further research is required for its generalization.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.74-89
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• 2015

The objective of this study is to present countermeasures for mitigation of flood damage with inundation analysis considering the effect of inland and river flood and prediction of flood inundation area, depth and time against emergencies caused by abnormal flood and local torrential rainfall. In this study, 2-D inundation analysis was fulfilled on the basis of river flood analysis applying to HEC-HMS and FLDWAV model and inundation analysis applying to SWMM model for the area of Shineum-dong, Gimcheon-si. Also expected inundation depth and area about probable rainfall of 100 and 200 years frequency were suggested. If expected inundation depth and flooding area is presented on the basis of this inundation analysis considering the effect of inland and river flood, it would be an important preliminary data to establish structural and nonstructural countermeasures for flood prevention. Also if flood risk map is prepared based on the result of inundation analysis, it would be useful to evacuate residents in high-risk area and regulate road and vehicle.