• Wind and Structures
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• v.9 no.4
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• pp.297-313
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• 2006

The concentration of air pollution along roads is higher than the surrounding area because ventilation efficiency has decreased due to the high-density use of space along roads in recent years. In this study, ventilation efficiency around a heavily traffic road covered by an elevated highway and hemmed in along its side by buildings is evaluated using Visitation Frequency (VF, the frequency for pollutant to return to the objective domain) and Purging Flow Rate (PFR, the air flow rate for defining the local domain-averaged concentration). These are analyzed using Computational Fluid Dynamics (CFD) based on the standard $k-{\varepsilon}$ model. The VF and PFR characteristics of four objective domains are analyzed in terms of the changes in wind direction and arrangements of the fencing dividing up and down direction in the road center under the elevated highway. The resulting VFs are more than 1.0 for all cases, which means that pollutants return to the objective domain restricted by the elevated highway and side buildings. The influence of the arrangement of the buildings around the objective domain and the structure in the domain on the VF is substantial. In cases where there are no obstacles under the elevated highway, the local air exchange rate in the domain tends to be improved. Using these indices, the urban ventilation efficiencies between different urban areas can be compared easily.

• Journal of Environmental Impact Assessment
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• v.13 no.6
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• pp.295-305
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• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking "environmentally sustainable transportation (EST)" projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents for the last six years. The EIA for railroad construction projects accounts for only 4.9% of total 918 project EIAs during 1998-2003, and the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water pollution, waste management, and noise, etc. We compared characteristics of environmental impacts of railroad construction with those of vehicle road construction, based on environmental and construction-planning indicators appeared in Environmental Impact Statements. Railroad construction usually requires longer tunnels and bridges for a given length than those for vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than 50% of those in vehicle road construction. To develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly recommended.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.691-698
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• 2015

In the area of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide ($TiO_2$), that is one of photocatalytic reaction material, is very efficient for removing NOx. Therefore, application of $TiO_2$ concrete is a good alternative in order to remove NOx which is a main cause of air pollution. This experimental study aimed to evaluate the long-term performance of $TiO_2$ concrete such as NOx removal efficiency due to performance period and environmental resistance for application of road structures. It was found that the $TiO_2$ is reasonable applicable on the road structure because $TiO_2$ concrete has a long-term performance.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.37-48
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• 1975

Air pollutants were measured to get useful data in preventing and controlling the pollution at industrial and semi-industrial, commercial, cross-road and residential areas by season in Busan from September 1973 to June 1974. Teated were dustfalls(ton/$km^2$/month)by Deposit Gauge method, sulfuric anhydride(mg $SO_3/day/100cm^2 PbO_2$) by Lead Peroxide candle method. The relations between pollution and metherologlcal factors and source of pollution were discussed, The findings are as follows: 1. The mean value of dustfalls was 24.8 tons rangi~ng from 12.5 tons to 44.5 tons. The highest amount of dustfalls of 29.0 tons was measured in crossroad areas while the 1oeest of 22.7 tons in commercial areas, and Winter the highest of 27.7 tons while in Spring the lowest of 21.2 tons. 2. The mean value of water soluble substances was 31.7 per cent, and seasonal variation of pH was shown as 4.20 in Autumn, 3.85 in Summer and 2.76 in Winter. 3. The mean value of sulfuric anhydride was 1.54mg ranging from 0.197mg to 4.162 mg. The highest concentration of sulfuric anhydride of 2.03mg was detected in cross-road areas while thelowest of 1.23mg in residential areas, and Summer the highest of 2.18mg while in Spring the lowest of 1.09mg(0. 92mg in Nov. 1973) 4. Dustfalls are more with the decreased of relative humidity and precipitation while concentrat:on of sulfuric anhydrides are more with the increased of relative humidity. 5. There is a probability of occuring chronic symptoms(respiratory and others) as the dustfalls with 24.8 tons and sulfuric anhydride with 1.54mg in Busan. According to this, it is the time to discuss monitoring system and systematic preventing methods.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.199-202
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• 1998

This paper describe an intelligent cruise control system for automobile. With the remarkable numerical increase of automobiles on the road, the optimized traffic flow control using the cruise control is one of the very important traffic problems to overcome the limitation of an existing road capacity. Based on this idea that minimize the fuel cost and the air pollution, and accept a driver's needs for driving, we have developed an intelligent cruise control system for vehicle. This proposed intelligent fuzzy cruise controller was successfully implemented using the fuzzy algorithm, the i80c196 μ-controller board and the throttle valve actuator. The field test results on an linear road was introduced.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.286-291
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• 2011

Onsite usage of construction equipment accounts for a 6.8% of air pollution in Korea. The high concentration of carbon dioxide in such emissions impact not only climate change, but also people's health. However, greenhouse gas emissions from onsite equipment usage have not yet been fully investigated. This study presents a comparative analysis on how much greenhouse gas is generated by various equipment types used in different construction activities. Two ongoing cases which involve a typical road construction project in Korea were selected for the comparison purpose. Greenhouse gas emissions from each onsite equipment usage of the different activities were estimated on the ground of design documents. The estimates were compared and analyzed to derive the main sources of greenhouse gas emissions. The result showed that earthwork constituted the largest part-more than 90%-among work types. Dump truck, bulldozer, and loader were major sources for such emissions. The study results are expected to be used as a basis for reduction of greenhouse gas emission from onsite equipment usage.

• Journal of ILASS-Korea
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• v.21 no.4
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• pp.207-213
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• 2016

To protect air pollution of urban area from motor vehicles, emission limits for diesel vehicles have been dramatically lowered in short period. But recent studies have shown that on-road NOx emissions of light-duty diesel vehicles are considerably higher than the values measured with laboratory test procedures used for emission certification. To tackle with this issue, Ministry of Environment have a plan to introduce EU RDE-LDV (Real-driving Emission-Light-duty Vehicle) regulation. In this study, 4 Euro 6 diesel vehicles have been tested with the new test procedures published by EU to estimate on-road NOx emissions using PEMS (Portable Emission Measurement System). The results have shown that the requirements of EU RDE-LDV could be met in driving condition of metropolitan area for constitution of test routes and validity of test results. In analysing with Moving Averaging Window method the completeness and normality of test data were validated with the requirement. On-road NOx emissions were quite deviated as test vehicles and higher than the new limit of on-road NOx emission enforced from Sept. 2017, which means that RDE-LDV can effectively reduce NOx emission of diesel vehicles in real driving conditions of Korea.

• Korea Trade Review
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• v.47 no.4
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• pp.271-292
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• 2022

In Korea, the road transport industry is pointed out as a major cause of air pollutants, so management control is needed. Existing studies used only positive input and output variables to measure regional efficiency. However, it is necessary to consider the environmental pollution problem in efficiency analysis. In this study, an undesirable SBM analysis using CO₂ was conducted to measure efficiency of domestic regions. In addition, SDM was conducted to examine the ripple effect between domestic regions. As a result of the analysis, the efficiency of the capital area such as Seoul, Gyeonggi, and Incheon was high in the road transport industry. However, the efficiency of the road transportation industry in Daegu and Gangwon was low. In the SDM analysis, it was found that the regional equipment capabilities had a great influence on efficiency. In order to improve efficiency, it is necessary to increase and improve the equipment capacity of the road transport industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.114-128
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• 2013

Greenhouse gas emissions have been an important issue in different countries because of their effects on global warming. The government has to organize greenhouse gas reduction measures suitable to regional characteristics by establishing annual implementation plans and comprehensive policies based on the UNFCCC. The transportation sector is one of the major contributors of air pollution; hence increasing need to estimate current and future traffic emissions precisely. Under these circumstances, a number of emission models have been developed recently. However, current methods of estimation cannot carry out effective analyses because it does not reflect vehicle movement characteristics. This study aims to present a new method for calculating road traffic emissions in Goyang city. A travel demand model is utilized to carry out GHG emission estimates according the traffic data (fleet composition, vehicle kilometers travelled, traffic intensity, road type, emission factors and speed). This study evaluates two approaches to estimate the road traffic emissions in Goyang City: Pollution-Emis and the Handbook of Emission Factors for Road Transport (HBEFA v.3.1) which is representative of the "average speed" and the "traffic situation" model types. The evaluation of results shows that the proposed emission estimation method may be a good practice if vigilant implementation of model inputs is observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.123-134
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• 2013

Strengthening vehicle emission regulation is one of important policies to improve air quality in urban area. Due to the limitation of specified driving cycles for certification test to reflect real driving conditions, additional off-cycle emission regulations have been adopted in US and being developed in Europe. The driving cycles of US or Europe have been used in emission certification for Korean light-duty vehicles, but it has not been known how well the driving cycles reflect various real driving patterns in Korea. In that point of view, it is required to estimate vehicle emission based on real road driving conditions to raise the effectiveness of vehicle emission regulation in Korea. In this study, real driving emission measurements have been conducted for three Korean light-duty vehicles with PEMS. The driving routes consisted of urban, rural and motorway in Seoul and Incheon. The data have been analyzed with various averaging methods including moving averaging windows method and compared to emission limits set with emission certification modes applied to tested vehicles. The results have shown that the real driving pollutant emissions of a gasoline and a LPG vehicles have been ranged quite lower than those of emission limits on CVS-75 driving cycle. But real driving NOx of a light duty diesel vehicle has been considerably higher than emission limit of NEDC driving cycle. The higher than expected NOx emission of a diesel vehicle might be caused by different strategy to control EGR in real driving condition from NEDC driving.