• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.51-61
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• 2002

In this dissertation, We demonstrated the Travel Time forecasting model in the freeway of multi-section with regard of drives' attitude. Recently, the forecasted travel time that is furnished based on expected travel time data and advanced experiment isn't being able to reflect the time-lag phenomenon specially in case of long distance trip, so drivers don't believe any more forecasted travel time. And that's why the effects of ATIS(Advanced Traveler Information System) are reduced. Therefore, in this dissertation to forecast the travel time of the freeway of multi-section reflecting the time-lag phenomenon & the delay of tollgate, we used traffic volume data & TCS data that are collected by Korea Highway Cooperation. Also keep the data of mixed unusual to applicate real system. The applied model for forecasting is consisted of feed-forward structure which has three input units & two output units and the back-propagation is utilized as studying method. Furthermore, the optimal alternative was chosen through the twelve alternative ideas which is composed of the unit number of hidden-layer & repeating number which affect studying speed & forecasting capability. In order to compare the forecasting capability of developed ANN model. the algorithm which are currently used as an information source for freeway travel time. During the comparison with reference model, MSE, MARE, MAE & T-test were executed, as the result, the model which utilized the artificial neural network performed more superior forecasting capability among the comparison index. Moreover, the calculated through the particularity of data structure which was used in this experiment.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.7-15
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• 2011

Emerged in early 1990s, so called 'Quick service' industry that provides faster delivery of small parcels than regular mail service accelerated use of motorcycles. As the economic grows, use of large bicycles (more than 250CC displacement) for leisure purpose has also rapidly increased. Traffic crash data clearly shows the increasing trend in motorcycle crashes. The ratio of motorcycle involved crashes out of total has increased from 5.7% in 2005 to 8.3% in 2008, and similar trend can be found in fatalities ratio as well. In this study, we assess the level of risk when motorcycles operate on motorways by analyzing traffic rule violation ratio, lane change behaviour, driving speed behaviors of motorcycles in Uninterrupted Traffic Flow Facilities and using PC-CRASH simulation we also calculate car shock impulses occurred when an accident happens. Analysis result shows that the motorcycle is different from the car in terms of lane change timing and average speed, and also shows motorcycle drivers tends to conduct more improper driving behavior particularly when traffic is congested. The results from this study could be usefully applied when the law enforcement agent decides whether bicycles shall be allowed to use motorways. The result could be also utilized as fundamental information for further study of bicycles' driving behavior.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.1-10
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• 1998

The temporary steel bridges which are constructed for detour and constructional expediency are consisted of H-beams(as superstructure) and H-piles(as substructure). Because these members are fastened by high-tension bolts, there are no expansion joints in these bridges. So, these kinds of bridges have no system which can relieve the excessive thermal stress. In this investigation, monitoring system was set up at temporary steel bridge and stress and temperature changes of H-beam are monitored. From these measured data, it is analyzed that the relationship between ambient and main-girder temperature change, between temperature and stress change. With these analyses, it is resulted that the thermal stress take main part of stress variation in this bridge and the restrain of thermal longitudinal displacement of H-pile. In addition, because the connection part of H-beam to H-beam is weak in the continuous spans, the sub-modelling is well apt to reflect the effect of thermal stress.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.219-227
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• 2001

In this study, the simulation was constructed using CA(Cellular Automata) rule to analyze the effect of incidents, which was verified using real-time VDS data and data collected on the field. The study analyzed the effect of incidents on highways by the simulation. The result appears to be statistically available with 5% of significance level. In order to analyze the effect of incident, the study classified time period of incidents and types of incidents in relation with traffic volume. Also, the effect of each type of incidents was analyzed in terms of time difference in sectional travel and delay time. In conclusion, little effect of incidents on traffic flow is noticed with light traffic volume but it becomes serious as the traffic volume increases. In addition, the delay happens to appear without incidents as the traffic volume increases over 2000 veh/hour. Also, when incidents happened during 45 minutes, the delay was about 425-722 veh·hour.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.103-112
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• 2008

In the feasibility analysis, Braess' Paradox results in the negative social benefit in spite of adding transportation facilities. Consequently, it has been difficult to judge on the investment of SOC projects. This research aims to analyze the Braess' Paradox in the feasibility analysis and to seek a remedy for the Paradox. Several experiments were conducted on the simple network under the various conditions. From the experiments, following findings were validated: Braess' Paradox occurred only if travel demands met within certain intermediate range. In terms of traffic assignment method, the SO was more likely to reduce the effect of the Braess' Paradox than the UE. However, the Braess' Paradox in the benefit of operating cost saving occurred in all cases and the paradox in the total benefit continued. In order to solve the problem, new link cost function considered travel time and operating cost simultaneously were suggested. As a result, the negative benefit was significantly decreased in the UE case and total negative benefit was no longer shown in the SO case through the analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.443-446
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• 2016

차량의 증가에 따라 다양한 교통문제들이 발생하고 있다. 이러한 문제를 해결하고자 IT기술과 융합된 지능형 교통시스템(ITS)의 연구가 진행되고 있다. 하지만 기존 ITS기술들은 국가별로 도로의 특성이 다양하기 때문에 쉽게 적용하기 어렵다. 그러므로 기존ITS기술들을 실험 및 테스트하기 위한 시뮬레이션 환경이 필요하다. 본 논문에서는 ITS기술들을 한국도로에 적용 할 수 있도록 하는 교정방법을 제안한다. 실험 도로는 항상 정체 현상이 발생하는 서울외곽순환고속도로를 선택하였고 실험 환경은 PTV사의 VISSIM 시뮬레이터를 이용하였다. 실험 결과 실제 속도 등고선 그래프와 시뮬레이션 환경에서의 속도 등고선 그래프의 병목현상이 발생하는 구간이 동일한 것을 확인 하였다. 또한 스테이션별 통행량 그래프를 비교하여 실제 교통량과 유사함을 확인하였다.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.1
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• pp.59-77
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• 2008

The purpose of this study is to investigate the impact of traffic-related air pollution on the urban population in the Metropolitan Seoul area. In particular, this study analyzes urban population exposure to traffic-related particulate materials(PM). For the purpose, this study examines the relationships between traffic flows and PM concentration levels during the last fifteen years. Traffic volumes have been decreased significantly in recent year in Seoul, however, PM levels have been declined less compare to traffic volumes. It may be related with the rapid growth in the population and vehicle numbers in Gyenggi, the outskirt of Seoul, where several New Towns have been developed in the middle of 1990's. The spatial pattern of commuting has changed, and thus and travel distances and traffic volumes have increased along the main roads connecting CBDs in Seoul and New Towns consisting of large residential apartment complexes. These changes in traffic flows and travel behaviors cause increasing exposure to traffic-related air pollution for urban population over the Metropolitan Seoul area. GIS techniques are applied to analyze the spatial patterns of traffic flows, population distributions, PM distributions, and passenger flows comprehensively. This study also analyzes real time base traffic flow data and passenger flow data obtained from T-card transaction database applying data mining techniques. This study also attempts to develop a space-time model for assessing journey-time exposure to traffic related air pollutants based on travel passenger frequency distribution function. The results of this study can be used for the implications for sustainable transport systems, public health and transportation policy by reducing urban air pollution and road traffics in the Metropolitan Seoul area.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.44-55
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• 2013

Intelligent transportation systems allow us to have valuable opportunities for collecting reliable wide-area coverage traffic and weather data. Significant efforts have been made in many countries to apply these data. This study identifies the critical points for classifying rain intensity by analyzing the relationship between rainfall and the amount of speed reduction. Then, traffic prediction performance by rain intensity level is evaluated using relative errors. The results show that critical points are 0.4mm/5min and 0.8mm/5min for classifying rain intensity (slight, moderate, and heavy rain). The best prediction performance is observable when previous five-block speed data is used as inputs under normal weather conditions. On the other hand, previous two or three-block speed data is used as inputs under rainy weather conditions. The outcomes of this study support the development of more reliable traffic information for providing advanced traffic information service.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.51-63
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• 2000

Dynamic traffic assignment(DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution algerian Recently, with its promise for In(Intelligent Transportation System) and GIS(Geographic Information System) applications, DTA have received increasing attention. This potential also implies higher requirement for DTA modeling, especially regarding its solution efficiency for real-time implementation. But DTA have many mathematical difficulties in searching process due to the complexity of spatial and temporal variables. Although many solution algorithms have been studied, conventional methods cannot iud the solution in case that objective function or constraints is not convex. In this paper, the genetic algorithm to find the solution of DTA is applied and the Merchant-Nemhauser model is used as DTA model because it has a nonconvex constraint set. To handle the nonconvex constraint set the GENOCOP III system which is a kind of the genetic algorithm is used in this study. Results for the sample network have been compared with the results of conventional method.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.1-9
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• 2010

Predictive information on the freeway incident impacts can be a critical criterion in selecting travel options for users and in operating transportation system for operators. Provided properly, users can select time-effective route and operators can effectively run the system efficiently. In this study, a model is proposed to predict freeway incident impacts. The predictive model for incident impacts is based on short-term prediction. The proposed models are examined using MARE. The analysis results suggest that the models are accurate enough to be deployed in a real-world. The development of microscopic models to predict incident effects is expected to help minimize traffic delay and mitigate related social costs.