• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.59-74
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• 2021

The domestic road space is reaching the limit of planar space distribution, and Increasingly, the importance of three-dimensional space distribution through the development of underground space. therefore, In this study, a study was conducted on a traffic control method that can safely induce two different traffic flows in the connection between the ground road and the underground road. Through VISSIM, we calculated the appropriate amount of outflow and inflow traffic compared to the capacity of the main line when there is a Merge/Diverge section in the underground road. and Through the analysis of the number of conflicts, the appropriate traffic control level for safety in the underground, A basic study was conducted on the level of risk in the underpass according to the level of delay in the ground part through the analysis of the delay scenario of the ground road.

• Journal of KSNVE
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• v.6 no.2
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• pp.253-259
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• 1996

Neighboring buildings which are sufficiently close to both sides of an urban street reflect sound back to the road and sound energy is increased by thses reflectors. Therefore, this study is forcussed on the prediction modeling for road traffic noise under reflective conditions. A part of a block in urban road is regared as a box. The sound energy density in the box is employed to establish prediction formulas in terms of independent variables. The variables. The validity of the proposed prediction method has been experimentally confirmed by applying it to actually measured road traffic noise data. On the whole, the agreement between measured and predicted noise levels appeared to be satisfactory.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.449-464
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• 2016

The purpose of this study is to test applicability of cut-through roundabouts at a congested intersection and to provide the traffic volume ranges for theirs application. Various test scenarios were developed according to variation of total traffic volume, left-turn ratio to total traffic volume, and ratio of major road traffic volume to minor road traffic volume. In addition, three intersection types of cut-through roundabout, roundabout, and signalized intersection were compared with respect to delay times for each scenario, resulted from the simulation using VISSIM. In case of the ratio of major road traffic volume to minor road traffic volume, 6:4, the delay times of cut-through roundabout decreased up to 30% of left-turn ratio to total traffic volume for 400vphpl, up to 20% for 500vphpl, up to 10% for 600vphpl. In case of the ratio, 7:3, they are the same as 6:4 for 400vphpl, 500vphpl, and 600vphpl but they decreased up to 30% for 300vphpl and up to 10% for 700vphpl. In case of the ratio, 8:2, they are the same as 7:3 for 400vphpl, 500vphpl, and 700vphpl but they were reduced by 10% to 30% for 300vphpl and 20% for 600vphpl. It is concluded that the smaller left-turn ratio to total traffic volume as well as the ratio of minor road traffic volume to major road traffic volume is, the more effective in reducing delay times the cut-through roundabout is. Cut-through roundabouts can be expected to reduce delay times at a signalized intersections with traffic conditions above-mentioned.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.311-315
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• 2008

This study was performed to investigate propagation characteristics and effects of road traffic noise generated from vehicles. Noise levels of expressway and general road were measured at four points in a straight line based on distance from the road, and analyzed. The average noise level of expressway was 78.9 dBA at 5 m, 76.4 dBA at 10 m, 72.0 dBA at 20 m, 69.0 dBA at 30 m. That of general road was lower about $3.1{\sim}3.5\;dBA$ than that of expressway. There was no significant difference in distance attenuation between expressway noise and general road noise. The farer the distance from source is, the more the attenuation is. The influence range of noise is assessed by noise environmental standards or road noise limits. Noise levels of the time zone were measured at a boundary line of apartment to grasp noise variation by time. The time zone of lowest noises was $3{\sim}4$ a.m. and that of highest noise was $8{\sim}10$ a.m. Data recorded on tapes were analyzed to understand the characteristics of frequency because these characteristics are important factors to plan the noise reduction measures, namely path measures.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.89-93
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• 2003

The ambient noise in modem society is the factor to give people serious influence. Noise barriers installation is mostly used in the apartment estate to protect countermeasure about the road traffic ambient noise. The purpose of this study is to suggest reference data fur design of traffic noise reduction in apartment estate. It finds out how the traffic noise is measured about a noise barriers and physical characteristics. The 57dB was measured from the noise barriers in a 2m point. An ambient noise's of the part to belong noise attenuation is big at the sound arresting area of the noise barriers as the distance far.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1177-1190
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• 2009

The traffic operating speed is one of important information to measure a road capacity. When we supply the information of the road of high traffic by using navigation, offering the present traffic information and the forecasted future information are the outstanding functions to serve the more accurate expected times and intervals. In this study, we proposed the traffic speed forecasting model using the accumulated traffic speed data of the road and highway and forecasted the average speed for each the road and high interval and each time interval using Fourier transformation and time series regression model with trigonometrical function. We also propose the proper method of missing data imputation and treatment for the outliers to raise an accuracy of the traffic speed forecasting and the speed grouping method for which data have similar traffic speed pattern to increase an efficiency of analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.244-257
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• 2017

Traffic congestion occurs from drivers' human factors such as driver reaction time, reckless lane change, and inexperienced driving. When Automated Vehicles are introduced, human factors are excluded, resulting in increased average vehicle speed, stabilizing traffic flow, and increasing road capacity. This study analyzed traffic flow changes through traffic volume-speed-density plots, and increased road capacity due to Automated Vehicles. As a result of the analysis, when rate of automated vehicles gests higher, the traffic flow became stable. Additionally, it was analyzed that when all vehicles were automated, the road capacity increased by about 120 %. It is expected that there will be a positive expectation in terms of traffic congestion and traffic demand management due to the introduction of Automated Vehicles.

• Journal of Internet Computing and Services
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• v.6 no.6
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• pp.85-97
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• 2005

In this paper, we construct the traffic information database by using the acquired data from the traffic information devices installed in road network, and, by referring to this database, propose the intersection simulation system which can dynamically manage the real-time traffic flow for each section of road from the intersections, This system consists of hierarchical 3 parts, The lower layer is the physical layer where the traffic information is acquired on an actual road. The traffic flow control framework exists in the middle layer. The framework supports the grouping of intersection, the collection of real-time traffic flow information, and the remote monitoring and control by using the traffic information of the lower layer, This layer is designed by extending the distributed object group framework we developed. In upper layer, the intersection simulator applications controlling the traffic flow by grouping the intersections exist. The components of the intersection application in our system are composed of the implementing objects based on the Time-triggered Message-triggered Object(TMO) scheme, The intersection simulation system considers the each intersection on road as an application group, and can apply the control models of dynamic traffic flow by the road's status. At this time, we use the real-time traffic information collected through inter-communication among intersections. For constructing this system, we defined the system architecture and the interaction of components on the traffic flow control framework which supports the TMO scheme and the TMO Support Middleware(TMOSM), and designed the application simulator and the user interface to the monitoring and the controlling of traffic flow.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.47-57
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• 2016

PURPOSES : This study aims to examine the differences between the existing traffic demand forecasting method and the traffic demand forecasting method considering future regional development plans and new road construction and expansion plans using a four-step traffic demand forecast for a more objective and sophisticated national highway maintenance. This study ultimately aims to present future pavement deterioration and budget forecasting planning based on the examination. METHODS : This study used the latest data offered by the Korea Transport Data Base (KTDB) as the basic data for demand forecast. The analysis scope was set using the Daejeon Metropolitan City's O/D and network data. This study used a traffic demand program called TransCad, and performed a traffic assignment by vehicle type through the application of a user equilibrium-based multi-class assignment technique. This study forecasted future traffic demand by verifying whether or not a realistic traffic pattern was expressed similarly by undertaking a calibration process. This study performed a life cycle cost analysis based on traffic using the forecasted future demand or existing past pattern, or by assuming the constant traffic demand. The maintenance criteria were decided according to equivalent single axle loads (ESAL). The maintenance period in the concerned section was calculated in this study. This study also computed the maintenance costs using a construction method by applying the maintenance criteria considering the ESAL. The road user costs were calculated by using the user cost calculation logic applied to the Korean Pavement Management System, which is the existing study outcome. RESULTS : This study ascertained that the increase and decrease of traffic occurred in the concerned section according to the future development plans. Furthermore, there were differences from demand forecasting that did not consider the development plans. Realistic and accurate demand forecasting supported an optimized decision making that efficiently assigns maintenance costs, and can be used as very important basic information for maintenance decision making. CONCLUSIONS : Therefore, decision making for a more efficient and sophisticated road management than the method assuming future traffic can be expected to be the same as the existing pattern or steady traffic demand. The reflection of a reliable forecasting of the future traffic demand to life cycle cost analysis (LCCA) can be a very vital factor because many studies are generally performed without considering the future traffic demand or with an analysis through setting a scenario upon LCCA within a pavement management system.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.49-65
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• 2012

Road traffic noise is closely related to road traffic environment, including traffic volumes by type and travel speed. In this study, we stated some issues and analyzed the relationships between road traffic noise and traffic flow characteristics. First, in attempt to find the answer to the question "When does the loudest traffic noise occur?" we reviewed the issue in the terms of traffic flow. As a result of analyzing level of service through Korea Highway Traffic Noise model, the actual maximum noise occurred in level of service D rather than level of service E, on the capacity state. It shows that maximum noise would be most likely to occur right before and after the peak hours. Second, this paper was looking for the method of a more easy and accurate traffic speed estimation to predict traffic noise. This paper proposed sketch planning techniques of speed-volume curve by level of service on Korea Highway Capacity Manual. As a result of trend line modeling, it was judged that quadratic form is a suitable function, and coefficient of determination ($R^2$) was higher than 0.96, respectively.