• Journal of Korean Society of Transportation
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• v.10 no.1
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• pp.21-40
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• 1992

We examine primarily the existing study procedures for freeway weaving section by comparing speed estimates. Most methods have poor predictions because of neglecting the weaving vehicle influ-ence. In this study we develop the speed prediction equation considering the weaving influence area i.e, weaving box. Assuming that speeds outside weaving box are similar to speeds in freeway basic sec-tions we develop speed equation in box based on the field data. Moreover level of service criteria and weaving analysis precedure are proposed under the new speed prediction equation.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.1-8
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• 2018

PURPOSES : In this study, design elements of rest areas for drowsy drivers are classified and appropriate criteria for each design element are presented. METHODS : By comparing and analyzing the design criteria for rest areas, the most appropriate installation criteria were suggested by considering the driving patterns of rest area users. RESULTS : As a result of the study, elements influencing the design of rest areas for drowsy drivers are suggested such as installation location and installation type. In addition, proper separation distance between resting areas was suggested considering vehicle flow, users' fatigue and physiological needs. Other criteria for rest areas were also suggested. CONCLUSIONS : Proper safety facilities were not installed in rest areas because appropriate criteria were not established. In this study, design elements were derived and installation criteria were designed so that rest areas could be used safely and conveniently.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.215-222
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• 2010

Average speed denotes a travel speed based on the average travel time of vehicles to traverse a segment of roadway, and average travel speed is used as a measure of effectiveness (MOE) suggested in the highway capacity manual (HCM) for evaluating the level of service (LOS) of roadway. Most of the urban freeways in our country are having congestion problem regardless of the rush hours as a high-speed highway with a speed limit of 80km/h or less. Especially traffic congestion within the ramp junction areas is becoming worse by the increased traffic and lack of links with the arterials around the urban freeway. So, the purpose in this study is to identify the traffic characteristics within the ramp junction areas of urban freeway, predict the average speed within the ramp junction areas based on the traffic characteristics identified, and finally prove the validity of the average speed predicted.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.63-75
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• 2018

A Service Area plays an important role in preventing accidents in advance by creating a space for long distance drivers or drowsy drivers to rest. Therefore, proper positioning of the expressway service area is essential, and it is important to analyze accurate demand forecasting and user travel behavior. Thus, this study analysis travel behavior and developed odel of the probability of using the service area by using the DSRC data collected by the RSE on the highway. According to the analysis, the usage behavior of highway service areas was most frequently when travel time was 90 minutes or more on weekdays and 70 minutes or more on weekends. The utilization rate of the service area estimated from the probability model of use of the rest area in this study was 1 % to 2 % error. The results of this study are meaningful in analyzing the behavior of the use of rest areas using the structured data and can be used as a differentiated strategy for selecting the location of rest areas and enhancing the service level of users.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.7-16
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• 2011

This study investigates the degree of dependency on freeways when auto travelers make route choices in the Seoul Metropolitan Area. The investigation is conducted based on aggregated auto trip data, defining the degree of dependency as the proportion of auto trips selecting freeways in their travel paths. The analyses reveal that the trips departing from the areas with higher accessibility to freeways tend to exhibit higher dependency on freeways. In addition, the dependency is significantly affected by the travel time differences between two paths including and excluding freeways, respectively. The number of service interchanges was found to be one of significant factors for trips to Incheon and Gyenggi areas. The finding indicates that the factors affecting the degree of dependency on freeways may vary depending on the areas' characteristics. The findings would enhance the understanding of drivers' route choice behavior in Seoul at an aggregate level.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.137-149
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• 1999

For decades, many traffic flow studies on the analysis and determination of level of service (LOS) for the weaving sections have been made to Provide several regression equations. Weaving and non-weaving speeds were dependent variables for the equations, with independent variables being weaving length, number of lanes, and weaving ratios. One of the difficulties in developing the equations was that the weaving areas were rare in Korea, so the statistical analyses for calibrating the equation parameter could not be performed in a desirable manner. In this regard, a new and stochastic methodology for predicting the weaving and non-weaving speeds within the weaving sections was required. In this study the following design variables were developed; influence area of the weaving section. headway distribution within the weaving section, maximum weaving volume of the weaving section, length of the ideal weaving section, and speed estimations for the weaving and non-weaving flows. The evaluation of the new model was made comparing the delay in the weaving section with the one in the freeway basic section.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.167-173
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• 2009

In general, an influenced area of merging section is defined as 500 m including 100 m upstream and 400 m downstream. However, from an observation of the actual traffic flow, it is found that merging effect influences more on downstream than upstream. In this study, an influenced area of merging section on freeway is analyzed by using turbulence which is defined as conflicts between vehicles. In order to overcome the limits of existing traffic flow detection system established with intervals of about 500 m, this study uses raw data collected from the detectors which are established in entrance ramps with similar road conditions. To divide data of each point into similar road conditions, the data of total 72 hours is sorted by Level of Service. An influenced area analyzed by standard deviation of speed is 700 m section of highway, including 300 m upstream and 400 m downstream, for both right and left ramps. It is the result including upstream 200 m more than previous studies.