• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.7-14
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• 2003

Statistics shows that 80% of freeway users travel less than 50km, and only 8% of them do over 100km. It means that the freeway is used for commuting. As a result, the freeway is not used efficiently and social cost is high. The current toll system aims for the efficient usage of the freeway by restraining short-distance trips and inducing long-distance ones. Thus, policies such as minimum toll system and discount for long-distance trips have been carried out. However. these two policies take no account of demand management between the freeway and alternative roads. They merely consider the compensation for charge on users, so the assessment of discount rate and distinction of distance are not reasonable. Consequently, not only the effective demand management but also the evaluation of those policies has been difficult to be achieved. The objective of this paper is to analyze those problematic policies and to establish a reasonable and improved toll system. In addition, this study presents the methodology to minimize social cost, which can be achieved by reducing short trips and encouraging long ones on the freeway. A new methodology of freeway toll system is applied and the results are presented.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.67-77
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• 2022

An automatic freeway bus-only lane enforcement system was developed and assessed in a real-world environment. Observation of a bus-only lane on the Youngdong freeway, South Korea, revealed that approximately 99% of the vehicles violated the high-occupancy vehicle (HOV) lane regulation. However, the current enforcement by the police not only exhibits a low enforcement rate, but also induces unnecessary safety and delay concerns. Since vehicles with six passengers or higher are permitted to enter freeway bus-only lanes, identifying the number of passengers in a vehicle is a core technology required for a freeway bus-only lane enforcement system. To that end, infrared cameras and the You Only Look Once (YOLOv5) deep learning algorithm were utilized. For assessment of the performance of the developed system, two environments, including a controlled test-bed and a real-world freeway, were used. As a result, the performances under the test-bed and the real-world environments exhibited 7% and 8% errors, respectively, indicating satisfactory outcomes. The developed system would contribute to an efficient freeway bus-only lane operations as well as eliminate safety and delay concerns caused by the current manual enforcement procedures.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.152-159
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• 1998

This paper presents a method evaluating benefits of ramp metering strategies on freeway safety. Based on the traffic and the accident data collected on a 4.2 km (2.6 mile) section of Interstate highway 35-West in Minneapolis, U.S.A., the relationship between traffic variables and safety measures is investigated. An aggregate specification that could be used to predict accident frequencies on freeways is proposed as a multiple regression form. The specification includes 15 minutes volume and occupancy data, which are commonly available from surveillance and control systems. The primary variables that appear to affect the frequencies of freeway accident are: vehicle-miles of travel, entrance ramp volumes and the dynamic effect of queue building. A simulation method evaluating the dynamic effect of control strategies on safety is proposed next. The potential benefits of freeway ramp metering on freeway safety are finally investigated via a proposed method.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.19-28
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• 1999

This study deals with developing Critical GaP Model and Merge Probability Model which describe traffic patterns in the microscopic view, for the Purpose of suggesting a proper design criteria within the climbing lane section. Minimum tolerance speeds at the end of the climbing lane are calculated 60km/hr for 2-lane freeway, and 75km/hr for 4-lane freeway. In case of 2-lane freeway, the result is same as existing design criteria. and a new value is 15km/hr higher than existing design criteria for 4-lane freeway. In addition, auxiliary length at the end of the climbing lane is needed about 200m for 4-lane freeway to adjust high minimum tolerance speed. Therefore we propose to increase minimum tolerance speed for 4-lane freeway.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.127-136
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• 2008

In these days, frequency of constructions on e freeway are increasing according as growing of the importance of e road maintenance and the road management. Work zone on the freeway where vehicles pass with high speed needs control method of lane closure and construction equipment. Because there are seldom researches in domestic study about reflecting characteristics of domestic road, sometimes we have applied for foreign cases to our traffic circumstance but it is not proper to apply for standard of other countries in our cases. foreign nation has different country square, condition of road, and level of people mind. Therefore, this study shows traffic accident characteristics in freeway work zones in Korea. At first, this study collected traffic accident data which include for 3 years $2003{\sim}2005$ in the whole freeway in Korea and then divided the data to five parts - level of the accident, type of the construction work, type of the accident, reason of the accident, according to geometric. According to comparing with non-work zones accident, this study found traffic accident characteristics in freeway work zones in Korea and suggested some alternative ideas for safety of work zones.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.99-104
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• 2015

PURPOSES : It is well known that experts determined the current standard dimensions of freeway lane markings. However, rigorous engineering rationale could be insufficient regarding whether or not the standard dimensions account for how visible the markings are to the driver. In this study, we seek to optimize the dimensions of freeway lane markings to improve their visibility to drivers. METHODS : The study was conducted as follows. First, alternative lane marking dimensions were selected which could be installed in a test construction site. Second, a video recording was made while driving on the test construction site. Third, subjects were shown the recorded video and then instructed to indicate their preference from among the various lane markings. Lastly, t-tests were applied to assess the statistical significance of differences in the preferences expressed. RESULTS : According to the t-test results, there was no significant difference in the preferences expressed regarding the lane marking widths. However, with regard to the dimensions of freeway lane marking, which represents line marking lengths, gap lengths, and widths of marking, the subjects expressed a preference for specific dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm. CONCLUSIONS : In considering the dimensions of freeway lane markings and their relation to visibility by the driver, it was found that dimensions such as 6 m:12 m,13 cm, 8 m:12 m,10 cm and 6 m:12 m,10 cm.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.631-634
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• 1999

A series of in-situ inspection and measurements have been conducted to estimate rebar corrosion incidence of freeway concrete bridges in Seoul metropolitan area. The results of this study have been analysed to identify the extent of chloride concentration and incidence of steel corrosion in various ages and in the different members of the structures. About 34% of the freeway structures had a value lower than - 350mV(vs CSE), so it could conclude that the excessive chloride concentration was a major cause of rebar corrosion.

• 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.

• Journal of Korean Society of Transportation
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• v.10 no.1
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• pp.5-20
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• 1992

Even though the types of ramp facilities in Korea are not various like other countries operations in these sections are very important because ramp merging and /or diverging flow affects freeway overall sections. In this study existing methodologies especially the gap acceptance model and the regression model in USHCM are evaluated with our field data. By gap acceptance model the merging capacity is founded 2.360 pcph which is increased by 7% than the capacity of freeway basic section. And in comparison of actual lane 1 volume to the estimation volume by HCM model the model slightly overestimates the actual volue.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.49
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• pp.125-133
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• 1999

Nonrecurring congestions are generally caused by random or less predictable events, such as accidents, spilled loads stalled or broken-down vehicles that, temporarily reduce the capacity of the freeway. The purpose of this paper is to present the effect of incidents on the traffic congestion on the urban freeway by simulation method. The simulation scenario is composed of two level traffic conditions, two level incident severities, and eight level incident durations. After incident, the recovering duration to the normal traffic flow, increased by linear of incident duration. Total vehicles travel time increased and average travel speed decreased by squares curve of incident duration. Considering incident impacts, incident management system is evaluated the major function of the urban freeway traffic management system. Also, necessary the related research to detect, verify, and develop effective response strategies for traffic incidents.