• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.841-846
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• 2011

Presently, the level of service(LOS) of the domestic roads are evaluated by using average speed of passing by vehicles. However, this method has been designed by considering the degree of congestion on the road only, without considering the reality of traffic safety. Therefore, for the LOS to serve as an index evaluating proper road design and operation, it should be able to deal with wider coverage than known factors which directly affects road users. Therefore the study wants to explore the concept of user cost, as a factor that covers traffic safety and flow, for evaluating roads. Also, the study wants to develop UML based user-centric design, not a one-time development method, for evaluating risk order of roads.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.95-102
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• 2011

Anti-icing system can immediately respond when snowing is expected or the snow comes down on the road surface. It has been recognized that the system can reduce traffic accidents and congestion by quickly removing the frozen road surface area. However, it is very difficult to implement this system due to the expensive equipment installation and operation cost, Recently, there was a developed program for predicting the freezing area using three-dimensional model and tracking the sun path. But, there is no objective analysis method and all developed approaches are different so that the general standard of anti-icing system is needed. In this study, we proposed the decision criteria for determining application priorities of the anti-icing system based on weather and road conditions, i.e., geometric and topographic conditions. Regional climate survey, topographical analysis, and dynamic vehicle simulation considered road geometry and skid resistance was conducted to standardize the installation method of anti-icing system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.3
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• pp.36-46
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• 2011

At present, the number of local governments using the Traffic Information Center are increasing and drivers are utilizing its traffic information from VMS installed on roads in cities. However, the cases of the user's utility of VMS about urban roads with special characteristics different from expressways and urban highways haven't been evaluated so far. Because VMS is a medium installed from a budget to provide traffic information, it is necessary to evaluate and manage the efficiency of users. This study judged that the efficiency of the drivers using VMS of urban roads most influences the duty on alternative route information provision so that it established its evaluation criteria. In addition, it needs to raise its value by many drivers' observation of VMS. Therefore, in case of the same conditions, the installation location of VMS should be a road section with much traffic volume so its the evaluation criteria was established. At present, the study results can be utilized to raise the user's utility of VMS installed in the urban roads.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.151-172
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• 1994

The objective of study is to evaluate design standards related to the allowable truck speeds, taper length and sign requirements together with the operating practices and economic justification for climbing lanes. Field surveys were carried out on seven climbing lanes, three on two-lane and four on four-lane freeways. Data collected are traffic volume, speed, usage rate and delay. It is found that current design criteria for determining the length of climbing lane, taper lengths, and traffic sign requirements must be upgraded. It is also recommended that regulations on the use of climbing lane be established to make it more effective. Further, economic analysis revealed that the climbing lane is economically justified for two-lane and four-lane freeway if the AADT is over 4,577 and 5,116 vehicles respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.663-669
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• 2011

In this study, the optimal length of left-turn lane in permissive left-turn signal system at the signalized intersection which has a left-turn bay is estimated. It is a simulation analysis using the queueing theory that estimate the length of left-turn lane. Traffic density conform to the standards of operating a permissive left-turn system of the Practical Manual Traffic Safety Facilities. And each of a left-turn arrival rate, a left-turn service rate, left-turn average queueing time, for green time average queueing vehicle, for red time average queueing vehicle and average queueing vehicle cycle is calculated. As a result of this study, we would learn how much the space should be secured at the signalized intersection which has a left-turn bay. The methodology using the queueing theory to work out the optimal length of waiting lane in the permissive left-turn signal system was presented.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.841-847
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• 2018

Since global energy consumption and demand for energy have dramatically risen, a focus on environmental problems and sustainability has become more important. Clean and renewable energy sources such as offshore wind power generation have received attention among new renewable energy options as alternative energy resources. Due to maintenance and operational perspectives, offshore wind farms have been planned for installation in many coastal waters. However, development of offshore wind farms faces interference from existing maritime traffic along the planned areas. In order to safely and effectively govern marine traffic in the vicinity of wind farms and inner areas, standard criteria are suggested to allow vessels to sail the internal waters of offshore wind farm areas. Therefore, the purpose of this study is to establish allowable criteria for sailing vessels and safety zones for offshore wind farms by investigating the local regulations of various offshore wind farm cases overseas. The commended inner safety zone of wind farms is proposed to be a distance of 150 % of the rotation diameter of the wind turbine rotor and a distance of 200 m from the outer wind turbine for the outer safety zone. Besides this, the allowable criteria for sailing vessels within a wind farm is proposed to have an air draft of 14.47 m south-west wind farm sea areas for a minimum margin to avoid hull contact through evaluation of the tide and height of a wind turbine. further studies will be needed to establish vessel sailing criteria among adjacent offshore wind farms as well as vessel sailing criteria within a single offshore wind farm.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.127-135
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• 2008

Intermodal or transfer facilities is always necessary wherever different modes meet at one place and exchanges of passengers among the modes take place. Design of intermodal or transfer facilities requires a careful consideration of numerous legal and technical factors. This study intends to suggest the fundamental principles needed for design the intermodal facilities to enhance the level-of-service for transfer passengers as well as the efficiency of operation. Previous studies and relevant legal documentation are reviewed and examined. Steps in the design procedures are suggested, and data necessary for designing the facility is suggested. The above principles are applied to the real design of Busan KTX station in order to identify the problems.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.127-137
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• 2006

This Paper Presents a novel incident detection method for using the speed-density difference between detectors. When a incident is happened the downstream traffic condition is mostly lower speed and higher density and the upstream is higher speed and lower density In respect of such characteristics, we can suggest a method for detecting an incident based on the speed-density information provided from detectors. The incident detection method is tested by using the accident data collected from the Cheonan-Nonsan Highway. The results show that suck an incident detection method can analyze the position of accident by comparing the speed-density difference between detectors. The work described in this paper is only at on early stage, in the sense that there are several areas to be further investigated in application of this method. such as setting a critical value for judging the incident. a level of accident wave, a varying Pattern between the incident locations and detectors, etc.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.13-20
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• 2007

For calculating the number of lane, it is essential to gain the 30th or 100th highest design hourly volume. The design hourly volume obtained from AADT multiplied by design hour factor. In this paper, we developed the regression models fur estimating the 30th highest hour volume and 100th highest hour volume as defined by AADT 50,000 criterion based on the data obtained the 34 monitoring sites in highway. By comparing the performance of the proposed models and conventional models using MAPE, the proposed model for 30th highest design hourly volume reduced the estimator error of 11.83% than that of conventional methods for less than AADT 50,000 and decreased estimation error of 22.17% than that of conventional method for more than AADT 50,000. Moreover, the proposed model for 100th highest design hourly volume reduced the estimator error of 8.16% than that of conventional methods for less than AADT 50,000 and decreased estimation error of 15.25% than that of conventional method for more than AADT 50,000.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.159-168
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• 2002

The Highway Capacity Manual(HCM) suggests estimating the average green time for the performance evaluation of the traffic actuated operation and Provides the average green time estimation model. However, the model provides with much room for improvements. This document proposes a new analytical model that overcomes the shortage of the HCM model. The average green times estimated by the HCM model and the proposed model were compared. A computer program using the proposed model was coded for the study, while the ACT348 program was used for the implementation of the HCM model Through the comparison study based on the 1,196 hypothetical simulation data surrogating field data, it was found that the average green times estimated by the proposed model yields much nicer one-to-one linear relationship to the simulation results than the ones from the HCM model in both exclusive-only and shared-permitted cases. The R2 values of the proposed and the HCM models with those cases are 0.90 and 0.56, and 0.86 and 0.57, respectively.