• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.147-158
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• 2010

Studies on the distribution of traffic demands have been proceeding by providing traffic information for reducing greenhouse gases and reinforcing the road's competitiveness in the transport section, however, since it is preferentially required the extensive studies on the driver's behavior changing routes and its influence factors, this study has been developed a discriminant model for changing routes considering driving conditions including traffic conditions of roads and driver's preferences for information media. It is divided into three groups depending on driving conditions in group classification with the CART analysis, which is statistically meaningful. And, elements of the driving conditions and the preferred media affecting the change of paths are classified into statistical meaningful groups through the CHAID analysis, and the major factors affecting the change of paths are examined. Finally, the extent that driving conditions and preferred media affect a route change is examined through a discriminant analysis, and it is developed a discriminant model equation to predict a route change. As a result of building the discriminant model equation, it is shown that driving conditions affect a route change much more, the entire discriminant hit ratio is derived as 64.2%, and this discriminant equation shows high discriminant ability more than a certain degree.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.26-32
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• 2016

An autonomous car(driverless car, self-driving car, robotic car) is a vehicle that is capable of sensing its environment and navigating without human input. Autonomous cars can detect surroundings using a variety of techniques such as radar, lidar, GPS, odometry, and computer vision. Advanced control systems interpret sensory information to identify appropriate navigation paths, as well as obstacles and relevant signage. Autonomous cars have control systems that are capable of analyzing sensory data to distinguish between different cars on the road, which is very useful in planning a path to the desired destination. An issue tree, also called a logic tree, is a graphical breakdown of a question that dissects it into its different components vertically and that progresses into details as it reads to the right.Issue trees are useful in problem solving to identify the root causes of a problem as well as to identify its potential solutions. They also provide a reference point to see how each piece fits into the whole picture of a problem. Using Issue-Tree menthods, transportation safety policies were developed with autonompus vehicle in mind.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.29-39
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• 2019

As mobile robot applications increase in real life, the need of low cost autonomous driving are gradually increasing. We propose a novel vision-based real-time lane detection and tracking system that supports autonomous driving of mobile robots in constrained tracks which are designed considering indoor driving conditions of mobile robots. Considering the processing of lanes with various shapes and the pre-adjustment of operation parameters, the system structure with multi-operation modes are designed. In parameter tuning mode, thresholds of the color filter is dynamically adjusted based on the geometric property of the lane thickness. And in the unstable input mode of curved tracks and the stable input mode of straight tracks, lane feature pixels are adaptively extracted based on the geometric and temporal characteristics of the lanes and the lane model is fitted using the least-squared method. The track centerline is calculated using lane models and the motion model is simplified and tracked by a linear Kalman filter. In the driving experiments, it was confirmed that even in low-performance robot configurations, real-time processing produces the accurate autonomous driving in the constrained track.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.113-120
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• 2005

Highway geometric design aims to provide drivers with safe and efficient road conditions. Highway design method of Korea doesn't consider demand characteristics of drivers, vehicles etc. Therefore there is a gap between designer's expectation and user's behavior and it hinders to make safer roads. It is required to develop the geometric design criteria and design method based on driving characteristics to provide safe and flexible design. This study suggested a geometric design method of horizontal curves on rural 4-lane highways based on speed distribution.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.32-49
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• 2024

In this paper, we analyzed the impacts of road traffic conditions and speed limit changes on traffic flow and safety. Travel speed and moving speed were set as traffic flow indicators and'moving speed-travel speed',speed deviation, large speed deviation ratio, and number of conflicts were set as safety indicators, and the impacts of changes in road traffic conditions and speed limits on these were analyzed. According to the analysis results, the speed limit had a significant impacts on the traffic indicators, but did not significantly affect the safety indicators. As a result of the statistical validity test, it was proven that the traffic flow index increases as the speed limit increases. However, although safety indicators often increase, their validity has not been proven statistically. Therefore, if the speed limit is set and operated by properly considering the traffic flow status according to various road conditions and changes in traffic volume, it can be said to match the speed at which drivers drive and improve traffic flow and safety. Therefore, it is expected that calculating the speed limit considering the traffic flow indicators and safety indicators presented in this paper and operating the speed limit according to changes in traffic volume will contribute to stabilizing the traffic flow on the road.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.78-89
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• 2022

Super - Bus Rapid Transit (S-BRT), adding the advantages of urban railroads to BRT, has emerged to solve the problem of low speed and reliability of the existing BRT. Notably, the S-BRT driveway is classified into exclusive lanes and roads, as BRT, in the domestic guidelines. However, S-BRT and BRT have different operating goals and characteristics, so it is necessary to systematize the S-BRT driveway. Therefore, this study classified an S-BRT driveway into exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane based on domestic conditions. Subsequently, a control strategy for transit signal priority in each driveway was presented by the study based on the characteristics of the driveway to achieve the S-BRT target service level. Finally, the S-BRT target service level was almost achieved, and the travel speed was high and increased in the order respectively in the exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane in the study. Hence, it is important to operate a transit signal priority considering the characteristics of each driveway when operating the S-BRT. In essence, this study is expected to be used as a reference for driveway design and transit signal priority operation when introducing S-BRT in each local government in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.287-300
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• 2022

The introduction of Connected and Automated(CAD) technology has a growing interests especially in areas with low demand for transport, where often the local transport services do not connect to peripheral areas for more efficient and convenient mobility services. However, there are few researches on CAD-based mobility services in areas with low demand for transport. Because current researches are mainly focuses on introduction of CAD-based mobility services in area with high demand for transport such as urban and highway. These two areas have different road environments and these differences require different driving technology especially related to Operational Design Domain(ODD). ODD is important factors for introduction of CAD-based mobility services. Therefore, we compare the road environments of areas with low demand for transport and areas with high demand for transport in terms of ODD. In addition, this paper proposes suggest guidance for the introduction of CAD-based mobility services in areas with low demand for transport such as rural and suburban areas.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.2
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• pp.150-156
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• 2011

Smart Highway is a next generation highway that significantly improves a traffic safety, reduces incidence of traffic accidents, and supports intelligent and convenient driving environments so that drivers can drive at high speeds in safety. In order to implement smart highway, it is required to gather a large amount of data including conditions of a road and the status of vehicles, and other useful data. To provide situation information of highway, it has been gathered traffic information using optical sensors(CCTV, etc.). However, this technique has problems such as the problem of information gathering, lack of accuracy depending on weather conditions and limitation of maintenance. It needs radar system which has not effect on environmental change and algorithm processing technique in order to provide information for a safety driving to driver and car. In this paper, it is used radar with 9.4GHz to test performance of a road surface and developed radar system for detecting test. And we compared and analyzed a performance of data acquired from each radar through computer simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.195-211
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• 2023

For the commercialization For the commercialization of autonomous vehicles (AV), the operational design domain (ODD) of automated driving systems (ADS) is to be clearly defined. A common language and consistent format must be prepared so that AV-related stakeholders can understand ODD at the same level. Therefore, overseas countries are presenting a standardized ODD framework and developing scenarios that can evaluate ADS-specific functions based on ODD. However, ODD includes conditions reflecting the characteristics of each country, such as road environment, weather environment, and traffic environment. Thus, it is necessary to clearly understand the meaning of the items defined overseas and to harmonize them to reflect the specific domestic conditions. Therefore, in this study, domestic optimization of the ODD classification system was performed by analyzing the domestic driving environment based on international standards. The driving environment of currently operating self-driving car test districts (Sangam, Seoul, and Gwangju) was investigated using the developed domestic ODD items. Then, based on the results obtained, the ranges of the ODDs in each test district were determined and compared.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.207-208
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• 2016

By according to increase the research for autonomous vehicle in automobile industries, the efficient of autonomous cargo truck instead of conventional driver cargo truck will be analyzed in logistics areas. The inland transportation has been serious problem such as traffic accident, traffic congestion in downtown, air pollution, noise and etc. even if it have a great effect to logistics industries. Especially there have to be improved its transportation schedule and sleepy driving in night which induced heavy accident in highway. In this study, the effectiveness of autonomous cargo truck will be analysed by considering the logistics cost including social effects.