• International Journal of Highway Engineering
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• v.17 no.5
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• pp.115-122
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• 2015

PURPOSES: Recently, many local governments have applied chicanes for traffic calming to ensure environment-friendly comfortable and safe roads. However, the geometry of a chicane is designed for speed reduction using a curved portion. This study aims to improve the road geometry conditions of chicanes for reducing carbon emissions and maintaining appropriate driving speeds by considering the relationship between road geometry and carbon emissions. METHODS: This study was conducted as follows. First, carbon emissions corresponding to changing acceleration of vehicles were studied. Second, vehicle acceleration caused by the relationship between the curve radius and the straight length was studied. Accordingly, desirable conditions of curve radius and length of the straight section for reducing carbon emissions were proposed. RESULTS: The existing literature on chicanes present the minimum value of stagger length and path angle in the primary variable condition. This study suggests the maximum values of the curve radius and length of straight section in the primary variable condition. Therefore, if a vehicle's speed at a chicane is 30 km/h, this study suggests a curve radius of up to 24 m. In addition, if the vehicle's speed is 24 km/h, this study suggests a length of straight section of up to 6.6 m. These are the geometric conditions for considering the control of acceleration to the vehicle's maximum speed. CONCLUSIONS: This paper proposes an application of geometric conditions to reduce carbon emissions and maintain appropriate speeds of vehicles through a combination of curve radius and length of straight section.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.69-77
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• 1993

Exhaust emissions are calculated as a product of the emission factor and the vehicle kilometer traveled(VKT). The emission factor is a function of several parameters such as vehicle model year, vehicle mileage, traffic conditions, etc. The representative driving cycles classified as ten different types of an average vehicle speed were selected by analyzing passenger car driving patterns in Seoul. 51 vehicles were sampled and analyzed by types of vehicles, fuels used, model years and vehicle mileages also, exhaust emissions of them were measured by chassis dynamometer. Regression equations between average vehicle speeds and exhaust emissions are made for the estimation of emission factors at different vehicle speeds. Annual emission rates of air pollutants from motor vehicles in Korea were 1116$\times10^3 ton, 149\times10^3 ton, 413\times10^3 ton and 67\times10^3$ ton for CO, HC, NOx and particulats, respetively in 1990. It was found that 56% of CO and 49% of HC were originated from passenger cars and taxis, in addition, 87% of NOx and 100% of particulates were from buses and trucks using diesel fuels.

• Journal of Climate Change Research
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• v.8 no.1
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• pp.41-50
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• 2017

As serious consequences of climate change became indisputable, vehicles based on fossil fuel has to be shifted toward more sustainable way to drastically reduce carbon emissions. Eco-friendly vehicles contribute mitigating climate change through reducing the greenhouse gas emissions. The goal of this research is to find ways to promote the eco-friendly vehicle industry in Korea. In order to achieve this goal, surveys are collected from the professionals of eco-friendly vehicle industry, and analyzed through Delphi method. Results show that the first thing is to promote the eco-friendly vehicle market by introducing the economic incentives. The second thing is to allow more emission credit for eco-friendly vehicle manufacturers. The third thing is to build more concrete infrastructure for the eco-friendly vehicles. The increase of the number of the electric or hydrogen charging system would be one of the good examples of the infrastructure. The fourth thing is that the government supports the research & development of eco-friendly vehicles. The fifth is to regulate that the government agency is mandatory to use the eco-friendly vehicles. The sixth thing is to provide the low-carbon certification for eco-friendly vehicles. The seventh thing is to support advertising the eco-friendly vehicles. The results from this research can be used as a guideline to make policies to stimulate the eco-friendly vehicle industry in Korea.

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.71-84
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• 1993

Currently the problem of air pollution caused by the motor vehicle emission is one of the most serious problems to be solved. Thus we needed the vehicle emissions audit procedure and technical innovation constraining the motor vehicle emission. The Korean Environmental Protection Agency currently audits automobiles for emissions compliance at assembly plants with multiple attribute multiple staged sampling plans. In order to establish the more reasonable audit procedure, the multiple staged sampling plan designed in this paper has been applied to the domestic vehicles by analyzing the statistic characteristics of the emission distribution. This paper summarizes the auditing procedure and develops methods for determining its statistical characteristics. Specifically, we consider how to evaluate a multiple staged sampling plan, give a procedure that efficiently estimates attribute-type probabilities from multivariate variables-type data, and quantify the effect of tightening the acceptable quality level of the sampling plan. As a result it can be proved that this audit procedure is the reasonable plan minimizing the AQL (Acceptable Quality Level) and is to be used effectively for the auditing procedure constraining the injurious gasses of the motor vehicles.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.125-132
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• 2015

PURPOSES : The present study aims to evaluate the added $CO_2$ emissions incurred from accelerating operation when to increase the speed up to the allowed level. METHODS : The methodology used are basically the relationship between emission rates and vehicle speeds or acceleration rate. These rates together are used to calculate the added $CO_2$ emissions incurred from accelerating operation. RESULTS : It was resulted that the all the emission rates are increasing proportionally to vehicle speeds or acceleration rates. Additionally, it was also resulted that allowable speeds increasing, the added emission rates are increasing rapidly. CONCLUSIONS : It may be concluded that if the allowable speed ranges are managed, $CO_2$ emissions during vehicle operation are much reduced. From this reason, it was found that the allowable speed during highway design and operation would be much necessary

• International Journal of Highway Engineering
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• v.15 no.4
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• pp.147-154
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• 2013

PURPOSES: To analyze the specific factors of drivers behaviors that amount of cause the greenhouse gas emissions per vehicle. METHODS: Drivers behaviors at intersections are analyzed on the conditions of acceleration and deceleration. RESULTS : First, it is resulted greenhouse gas emissions per vehicle is produced more at intersections than at the main lines of highway. Second, it is resulted that the average speed, the average acceleration rate and the maximum speed are three major factors to produce greenhouse gas per vehicle in acceleration sections. Third, it is resulted that rapid deceleration 20m before entering intersections is the major factor to produce greenhouse gas per vehicle in deceleration sections. CONCLUSIONS: At intersections, sudden acceleration and deceleration is not good for greenhouse gas emissions. Thus, and the average speed, the average acceleration rate and the maximum speed are the chosen as factors to be controlled for drivers' behavior to reduce vehicles' greenhouse gas at intersections.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.94-104
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• 2010

The capacity of highway is restricted and traffic congestion is caused by increasing traffic demand. Also, greenhouse gases are increased by traffic congestion. CDM (Clean Development Mechanism) is an idea of interest to reduce greenhouse gases. However, CDM's cases applied in traffic field are rare. Thus, it is necessary that methodology to reduce greenhouse gas should be developed and applied to CDM. A methodology for identifying greenhouse gas emissions was developed in this paper. This methodology was developed on the basis of baseline methodology registered at UN. Travel time and speed in the conventional traffic condition and in the automated traffic condition are compared by BPR function. The calculated speed applied to emission factor equation and then $CO_2$ emissions was calculated. A simulation was executed to evaluate the validity of the developed methodology. In the result, advanced vehicle's $CO_2$ emissions are more than conventional vehicle's $CO_2$ emissions in the stable flow condition. However, advanced vehicle's $CO_2$ emissions are less than conventional vehicle's $CO_2$ emissions in the unstable flow condition. It is assure that capacity of highway is enhanced and efficiency of highway is improved by adopting advanced safety vehicle in the smart road.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.177-191
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• 2021

One of the major causes of serious air pollution worldwide is emissions from road transportation. A number of countries are working to reduce vehicle emissions, and the Seoul Metropolitan Government is also implementing active policies to reduce emissions by setting a target of 40% by 2030. Implementing these policies requires the introduction of practical indicators. Most of the domestic emissions are calculated by the emission coefficient, a function of speed at the National Institute of Environmental Research under the Ministry of Environment, but the dynamic variable speed is limited to being used as an indicator of the number of eco-friendly vehicles. Therefore, this study calculated the emission rates in Seoul using the vehicle registration data of Seoul and the vehicle inspection data from the Korea Transportation Safety Authority. The tendency of emissions was determined according to key variables such as vehicle type, fuel and mileage. Emissions were based on carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter measured by vehicle inspection from the Korea Transportation Safety Authority. As a result, the emission rates showed a significant trend according to the model year and mileage. This can be used as a policy indicator to preferentially switch commercial vehicles with old model years and long mileage when switching eco-friendly vehicles in Seoul.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.73-81
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• 2006

A commercial diesel engine was converted into a dedicated natural gas engine to reduce the exhaust emissions in a retrofit of a diesel-fueled vehicle. The cylinder head and piston were remodeled into engine parts suited for a spark ignition engine using natural gas. The remodeling of the combustion chamber changed the compression ratio from 21.5 to 10.5. A multi-point port injection(MPI) system for a dedicated natural gas engine was also adopted to increase the engine power and torque through improved volumetric efficiency, to allow a rapid engine response to changes in throttle position, and to control the precise equivalence ratio during cold-start and engine warm-up. The performance and exhaust emissions of the retrofitted natural gas engine after remodeling a diesel engine are investigated. The emissions of the retrofitted natural gas engine were low enough to satisfy the limits for a transitional low emission vehicle(TLEV) in Korea. We concluded that a diesel engine can be effectively converted into a dedicated natural gas engine without any deterioration in engine performance or exhaust emissions.

• International Journal of Highway Engineering
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• v.18 no.3
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• pp.115-125
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• 2016

PURPOSES : This study proposes a methodology to collect data necessary for microlevel emission estimation, such as second-by-second speeds and road grades, and to accordingly estimate emissions. METHODS : To ease data collection for microlevel emission estimation, a vehicle equipped with speed- and location-recording instruments as well as equipment for measuring road geometry was used. As a case study, this vehicle and the proposed methodology were used on a 10-km-long highway in Yongin City, Korea. Emissions from the vehicle during driving were estimated in various microscale driving conditions. RESULTS : Differences in the estimated emission under different microscale driving conditions cannot be ignored. Compared with the estimations obtained when second-by-second data were not considered, CO and NOx emissions were more than threefold higher when considering second-by-second speed; similarly, CO and NOx emission estimations were higher by approximately 10% and 3%, respectively, when considering second-by-second road grade. CONCLUSIONS : The proposed method can estimate vehicle emissions under real-world driving conditions in such applications as road design and traffic policy assessments.