• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.51-62
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• 2008

An innovative feature of this study is to propose a methodology for evaluating safety performance in real time based on vehicle trajectory data extracted from video images. The essence of evaluating safety performance is to capture unsafe car-following and lane-changing events generated by individual vehicles traveling within video surveillance area. The proposed methodology derived three indices including real-time safety index(RSI) based on the concept of safe stopping distance, time-to-collision(TTC), and the collision energy based on the conservation of momentum. It is believed that outcomes would be greatly utilized in developing a new generation of video images processing(VIP) based traffic detection systems capable of producing safety performance measurements. Relevant technical challenges for such detection systems are also discussed.

• Journal of Auto-vehicle Safety Association
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• v.9 no.1
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• pp.6-12
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• 2017

Regulation for the testing and operation of automated vehicles on public roadways has been recently developed all over the world. For example, the licensing standards and the evaluation technology for automated vehicles have been proposed in California, Nevada and EU. But specific safety evaluation scenarios for automated vehicles have not been proposed yet. This paper presents safety evaluation scenarios for extraordinary service permission of automated vehicles on highways. A total of seven scenarios are selected in consideration of safety priority and real traffic situation. Six scenarios are relevant with lane keeping and one scenario is relevant with lane change. All scenarios are developed based on existing ADAS evaluation scenarios and repeated simulation of automated vehicle algorithm. Safety evaluation factors as well as scenarios are developed. The safety factors are based on existing ADAS ISO requirements, ADAS safety factors and current traffic regulations. For the scenarios, a hunter vehicle is needed in addition to automated vehicle evaluated. The hunter vehicle performs multiple roles like preceding vehicle, cut-in vehicle and so on. The hunter vehicle is also automated vehicle equipped with high performance GPS, radar and Lidar. All the scenarios can be implemented by driving a lap on a KATRI ITS test track. These scenarios and safety evaluation factors are investigated via both a computer simulation and an experimental vehicle test on the test track. The experimental vehicle test was conducted with two automated vehicles, which are the evaluated vehicle and the hunter vehicle.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.42-54
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• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.32-38
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• 2018

Studies on classification of national roads have been continued, but there is little research on the classification of urban arterial roads. Due to the increase of traffic volume, urban arterial roads do not perform well as main roads. In this paper, the function of urban arterial road was established by using cluster analysis using traffic characteristics. Traffic characteristics such as traffic volume, weekend coefficient and speed coefficient were used to establish the functions of 55 main arterial roads in Seoul. The results of this paper are compared with those of the method using AADT. The method using AADT classifies the characteristics according to the traffic volume of the whole lane. In this paper, however, the results are derived using the traffic volume per lane reflecting the actual traffic volume. In addition, the functional classification of the arterial roads in Seoul was compared with the results of this paper to verify that the traffic characteristics were reflected. As a result, the method presented in this paper is more effective in showing traffic characteristics than the current highway functional classification method, and the functional classification system will be helpful for road extension and planning design.

• Journal of the Korean housing association
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• v.11 no.4
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• pp.85-96
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• 2000

The purpose of this study was to evaluated noise environment of the low-rise multi-family house in Athens, Georgia. The results of this study can be applied to the prevention of noise when planning multi-family houses, roads and cities in Korea. The subjects of this study were the place of 1m, 10m, 50m, 100m from 4-lane road ofT apartment and 233 residents lived in the low-rise multi-family houses in Athens. The results of this study were as follows. 1. The average noise level at 1m, 10m, 50m and 100m was 55.5dB, 46.7dB, 43.0dB, 43.0dB and 41.2dB respectively from 4-lane road of T apartment. From the view of the standard in this study, the physical noise was good. 2. The results of the residents subjective response on the noise were as follows. The external noise residents felt - that was a noise by operating machines, and traffic noise - ware as 2.57 on average. The noise by the daily activities, the noise of nature are a little as 2.38 on average. They were disturbed a little by the external noise. They felt the solid born sounds(average 2.49) more than airbone sound(average 2.23) by the internal noise. They are suffered worse from noise in summer and they worse from 8-12 oclock due to external noise and 16-20 oclock due to internal noise. Comparing the noise environment of Korean with that of American, I found a meaningful difference of nature and the noise of daily activities of external noise and all internal noise.

• Convergence Security Journal
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• v.12 no.6
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• pp.31-37
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• 2012

Today, the core technology of an automobile is becoming to IT-based convergence system technology. To cope with many kinds of situations and provide the convenience for drivers, various IT technologies are being integrated into automobile system. In this paper, we propose an convergence system, which is called Augmented Driving System (ADS), to provide high safety and convenience of drivers based on image information processing. From imaging sensor, the image data is acquisited and processed to give distance from the front car, lane, and traffic sign panel by the proposed methods. Also, a converged interface technology with camera for gesture recognition and microphone for speech recognition is provided. Based on this kind of system technology, car accident will be decreased although drivers could not recognize the dangerous situations, since the system can recognize situation or user context to give attention to the front view. Through the experiments, the proposed methods achieved over 90% of recognition in terms of traffic sign detection, lane detection, and distance measure from the front car.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1617-1623
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• 2018

It is necessary to develop a next generation location referencing method with higher accuracy as advanced technologies such as autonomous vehicles require higher accuracy of location data. Thus, we proposed a framework for a lane-level location referencing method (L-LRM) based on high-precision digital road network map, and developed a tool which is capable of analyzing and evaluating the proposed method. Firstly, the necessity and definition of location referencing method was presented, followed by the proposal of an L-LRM framework with a fundamental structure of high-precision digital road network map for the method. Secondly, an architecture of the analysis and evaluation tool was described and then the Windows application program was developed using C/C++ programming language. Finally, we demonstrated the performance of the proposed framework and the application program using two different high precision digital maps with randomly generated road event data.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.3-10
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• 2012

This study dealt with traffic accidents occurring within roundabouts. The objective was to develop roundabout accident models for different driving types by using simultaneous equations. In pursuing the above, this study used a statistical program SPSS 17.0 to accommodate data from 148 accidents occurred within 39 roundabouts of Korea. In addition, the 2SLS(2 stage least square) estimation method was adopted to calibrate the models. The main results are as follows. First, both the number of accidents and the EPDO were evaluated to have bilateral relationships. Second, all 6 different simultaneous equation models according to driving types were found to be statistically significant. Third, the developed models were compared to each other with respect to either common or specific variables. Finally, variables such as ADT, conflicting rate, heavy vehicle ratio, circulatory roadway width, number of circulatory roadway lane, approach lane width, average approach lanes, parking places, and bus stops were selected as independent variables for the models.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.97-106
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• 2010

Environmental issues resulting from climate change and energy crises have become global issues, and cycling has gained greater popularity for sustainable transportation. Though many cities are trying to build bicycle roads, it is not easy to implement bicycle roads because there is little available space for bicycle facilities. Therefore, road diets have become more popular in Korea. However, there has been no intensive research to date of their impacts. The purpose of this research is to evaluate the effects of road diets and construction of bike lanes. Every benefit, including energy benefit, environmental benefit, and health benefit is considered, while only time savings benefit has been considered in previous studies. The benefit analysis for the Seoul metropolitan area as a case study shows that road diets have a (1) time saving benefit for only five percent of the mode share and (2) enough total benefit even if bicycle mode share is less than two percent.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.278-291
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• 2017

Effective installation and operations of traffic safety signs in the advance warning area is of considerable interest for safer traffic management at freeway work zones. This study evaluated the feasibility of traffic safety sign installation based on a driving simulation experiment to take drivers' responsive characteristics into consideration. Both the compliance rate for speed limit and a lane-changing safety index were used for evaluating a set of driving simulation scenarios. It was identified that providing speed limit signs to reduce speed in advance and afterward guiding lane-changing could lead to safer maneuvering of vehicles entering work zones. The outcomes of this study are expected to be useful for revising freeway work zone management policies toward crash prevention.