• International Journal of Highway Engineering
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• v.11 no.3
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• pp.121-128
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• 2009

This study has proposed the signal operating system to use both semi-actuated signal control and pedestrian push-button as a way to make up for the problems of 3 leg intersections which are operated inefficiently in the signal operation, one of the methods of traffic operations. In case of the semi-actuated signal control, it can reduce delay inside the intersection by serving to uncongested traffic on the main road where there is not much traffic volume on the secondary road and push-button signal can reduce unnecessary waiting time it could happen to vehicles by operating it though there is no pedestrian. Quantitative analysis was tried regarding the average delay reduction per vehicle using VISSIM, microscopic simulation program regarding how much effect it has compared with the existing signal control system and semi-actuated signal control system when the above two advantages are collected. The field test was performed for one three-leg intersection of Incheon. According to respectively signal control method pedestrian traffic changed and executed a sensitivity analysis. The result which compares the average delay time per a vehicle of scenarios, the signal control method of using the pedestrian push-button system in comparison with the fixed signal control method showed to decrease effect of a minimum 3.7 second (10%), a maximum 5.8 second (16%). When the pedestrian traffic volume was 20% or less of the measurement traffic volume, The signal control method of using the pedestrian push-button system appeared to be more efficient the semi-actuated signal control with object intersection.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.3
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• pp.233-248
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• 2012

The national emission from energy sector accounted for 84.7% of all domestic emissions in 2007. Of the energy-use emissions, the emission from mobile source as one of key categories accounted for 19.4% and further the road transport emission occupied the most dominant portion in the category. The road transport emissions can be estimated on the basis of either the fuel consumed (Tier 1) or the distance travelled by the vehicle types and road types (higher Tiers). The latter approach must be suitable for simultaneously estimating $CO_2$, $CH_4$, and $N_2O$ emissions in local administrative districts. The objective of this study was to estimate 31 municipal GHG emissions from road transportation in Gyeonggi Province, Korea. In 2008, the municipalities were consisted of 2,014 towns expressed as Dong and Ri, the smallest administrative district unit. Since mobile sources are moving across other city and province borders, the emission estimated by fuel sold is in fact impossible to ensure consistency between neighbouring cities and provinces. On the other hand, the emission estimated by distance travelled is also impossible to acquire key activity data such as traffic volume, vehicle type and model, and road type in small towns. To solve the problem, we applied a hierarchical cluster analysis to separate town-by-town road patterns (clusters) based on a priori activity information including traffic volume, population, area, and branch road length obtained from small 151 towns. After identifying 10 road patterns, a rule building expert system was developed by visual basic application (VBA) to assort various unknown road patterns into one of 10 known patterns. The expert system was self-verified with original reference information and then objects in each homogeneous pattern were used to regress traffic volume based on the variables of population, area, and branch road length. The program was then applied to assign all the unknown towns into a known pattern and to automatically estimate traffic volumes by regression equations for each town. Further VKT (vehicle kilometer travelled) for each vehicle type in each town was calculated to be mapped by GIS (geological information system) and road transport emission on the corresponding road section was estimated by multiplying emission factors for each vehicle type. Finally all emissions from local branch roads in Gyeonggi Province could be estimated by summing up emissions from 1,902 towns where road information was registered. As a result of the study, the GHG average emission rate by the branch road transport was 6,101 kilotons of $CO_2$ equivalent per year (kt-$CO_2$ Eq/yr) and the total emissions from both main and branch roads was 24,152 kt-$CO_2$ Eq/yr in Gyeonggi Province. The ratio of branch roads emission to the total was 0.28 in 2008.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.129-135
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• 2017

The respective delivering vehicle loaded with the own cargo moves into the respective delivery area. At the base, the delivery points D1 and D2, for example, have the same starting point but the destination is different. The average delivering time of the delivery vehicle is mostly more than 8 hours a day. Therefore, the efficiency of delivery is generally low. In this study, the deliveries will be forwarded from a base station to a delivery point where cross docking will be applied to a single vehicle, and will be distributed from the cross docking point through cross docking. If the distribution is implemented, one vehicle will not have to be operated from the base to the cross docking point. In that case, logistics cost will be reasonably saved by the reduction of transportation cost and labor time. If one vehicle only runs from the base to the cross docking point, each vehicle will be operated in two shifts, and the vehicle operation can be efficiently implemented. This research model is based on the assumption that the 3 types of ratios between the traffic volume of the vehicles starting at the base and the vehicles waiting at the cross docking point are set to the first ratio of 30% to 70%, the second ratio of 50% to 50% and the final ratio of 70% to 30%. As a result of the study, The delivery time in the cross docking point is much higher than that in present on the condition that the cargo volume in the D2 area is more than 50%. Likewise, the delivery time is slightly higher on the condition that the cargo volume is less than 50%. Time is reduced in terms of 50% model like AS-IS model.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.77-83
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• 2011

This study deals with the effectiveness of roundabout. The goal is to comparatively analyze the operational effectiveness related to the conversion of rotary to roundabout in Korea. In pursuing the above, this study gives particular attentions to investigating the existing 20 rotaries and developing the networks of before-and-after improvement using VISSIM, and comparatively analyzing the effectiveness. The domestic rotaries were analyzed to need many improvements of geometric structure for the effective operation of roundabout. The main results are as follow. First, when the present condition of traffic volume were applied, the operational effect of rotary were evaluated to be better than roundabout, but the difference analyzed to be small. Second, the average delay per vehicle in the rotaries of urban area were analyzed to rapidly increase according to the growth of traffic volume. Finally, the average speed of roundabout were evaluated to be less (about 10km/h) than that of rotary, because the traffic volume of rural area were less than that of urban area.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.135-145
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• 2008

As a fundamental input to the travel demand forecasting, OD has been always a concern in obtaining the accurate link traffic volume. Numerous methods were applied thus far without a complete success. Some existing OD estimation techniques generally extract regular samples and expand those sample into population. These methods, however, leaves some to be desired in terms of accuracy. To complement such problems, research on estimating OD using additional information such as link traffic volume as well as sample link use rate have been accomplished. In this paper, a new approach for estimating static origin-destination (OD) using probe vehicle has been proposed. More specifically, this paper tried to search an effective sample rate which varies over time and space. In a sample test network study, the traffic volume error rate of each link was set as objective function in solving the problem. As a key result the MAE (mean absolute error) between expanded OD and actual OD was identified as about 5.28%. The developed methodology could be applied with similar cases. Some limitations and future research agenda have also been discussed.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.41-49
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• 1997

In South Korea since 1970s the rapid development of economic growth has brought about "Urbanization" in many areas and also raised the level of people's life in many ways. At the same time, however, the industrialization and overpopulated districts in many areas have caused the problems of air pollution in necessary. Among those air pollution, in particular, in large cities has become more serious since 1990s than before. Air pollution, like TSP and SO$_{x}$ caused by heating, generation of electric power and industrialization in 1980s, showed as that of the type of an underdeveloping country and was not hazardous enough to people in the least. Unfortunately, in 1990s NO$_{x}$, CO and O$_{3}$ caused by the soaring numbers of many types of cars have exhausted air pollutant more hazardous as the same air pollution type of many developed countries. So, the purpose of this study would be to analyze the changes of concentration of NO$_{x}$ and CO on environmental air by traffic volume and from the side drive way to the degree of distance in Sungnam City, and recognize the citizens' consciousness to air pollution and suggest the best walking point in part, and plan to design the reasonable use of cars and finally make the air quality improve toward the better-ment in part. From the research result we can know that people walking in the street would be protected from the hazardous air pollutant caused by the cats if they walk apart from a drive way as far as they can in the street. Accordingly, it might, to minimize th affect of air pollution, be thought to be desirable that the consideration of in introduction the system that the vehicle using the diesel engine motor should use the centered-lane aparted from road. Another to be desirable is that along side the road, the trees inhaled the pollution should be planted.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.57-64
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• 2017

This study was reviewed the noise reduction effects with installation of 'point to point speed camera' for controlling the speed of the car. The multiple regression analysis was performed to know how the relationship between the noise level and these parameters, such as measured traffic volume and rate of heavy vehicle and weighted average speed was changed with and without the 'point to point speed camera'. In the analysis results shows that the less traffic volume, the more noise reduction effect has been increased and the more traffic volume, the more noise reduction effect has been reduced. And noise reduction effects by the 'point to point speed camera' was different from each measured point. The cause of the difference was determined that inadequate 'point to point speed camera' position to see the effect of noise reduction. It is determined to require a more study to improve the noise reduction effects of the 'point to point speed camera' such as the camera position adjustment.

• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.155-165
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• 2014

This study measured and compared the variation of ventilation rate and fan energy consumption according to various control strategies after installing wireless sensor-based pilot ventilation system in order to verify the applicability of demand-controlled ventilation (DCV) strategy that was efficient ventilation control strategy for underground parking lot. The underground parking lot pilot ventilation system controlled the ventilation rate by directly or indirectly tracking the traffic load in real-time after sensing data, using vehicle detection sensors and carbon monoxide (CO) and carbon dioxide ($CO_2$) sensor. The ventilation system has operated for 9 hours per a day. It responded real-time data every 10 minutes, providing ventilation rate in conformance with the input traffic load or contaminant level at that time. A ventilation rate of pilot ventilation system can be controlled at 8 levels. The reason is that a ventilation unit consists of 8 high-speed nozzle jet fans. This study proposed vehicle detection sensor based demand-controlled ventilation (VDS-DCV) strategy that would accurately trace direct traffic load and CO sensor based demand-controlled ventilation (CO-DCV) strategy that would indirectly estimate traffic load through the concentration of contaminants. In order to apply DCV strategy based on real-time traffic load, the minimum required ventilation rate per a single vehicle was applied. It was derived through the design ventilation rate and total parking capacity in the underground parking lot. This is because current ventilation standard established per unit floor area or unit volume of the space made it difficult to apply DCV strategy according to the real-time variation of traffic load. According to the results in this study, two DCV strategies in the underground parking lot are considered to be a good alternative approach that satisfies both energy saving and healthy indoor environment in comparison with the conventional control strategies.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.12
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• pp.1191-1198
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• 2012

Highway traffic noise is the one of the most frequent pollutant source of environmental claims in Korea for the last 10 years. For abating the noise from the highways, characteristics of highway noise source should be investigated and identified before performing the abatements. Highway noises are affected by traffic volume, vehicle types and speed, tyre and pavement types. In this study, highway noises which measured from different pavements have been analyzed and compared. Especially, the noise from the asphalt concrete pavement, cement concrete pavement and low-noise pavement have been measured simultaneously at the same traffic condition and compared each other. Hopefully, the data of the study may be used for abating highway noise and further studies.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.52-61
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• 2018

This research suggested the traffic signal timing calculation model for signal intersections based on sectional travel time. A detection system that collects sectional travel time data such as Urban Transport Information System(UTIS) is applied. This research developed the model to calculate saturation flow rate and demand volume from travel time information using a deterministic delay model. Moreover, this model could determine the traffic signal timings to minimize a delay based on Webster model using traffic demand volume. In micro simulation analysis using VISSIM and its API ComInterface, it checked the saturation conditions and determined the traffic signal timings to minimize the intersection delay. Recently, sectional vehicle detection systems are being installed in various projects, such as Urban Transportation Information System(UTIS) and Advanced Transportation Management System(ATMS) in Korea. This research has important contribution to apply the traffic information system to traffic signal operation sector.