• Journal of ILASS-Korea
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• v.22 no.4
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• pp.218-224
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• 2017

In order to improve the quality of air in urban areas, the emission regulations are being strengthened by the government. The on-road test of light-duty vehicles was started with PEMS because certification test mode does not sufficiently reflect on-road conditions. Therefore, The PEMS-based test was implemented from Sep. 2017 in Europe and Korea. However, this is lack of data on various on-road patterns in Korea. The purpose of the present study has analyzed the effect of speed per acceleration and acceleration on NOx emission on-road driving. The test route consisted of urban, rural, and motorway in Seoul. This study has been conducted by Euro-6 vehicles using on SCR system with PEMS. The on-road emission characteristics were evaluated by moving averaging windows (MAW) method. In results, RDE-NOx by severe driving pattern has been 1.4 times higher than soft driving pattern NIER Route 1.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.55-66
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• 2020

This study developed four algorithms and their associated indices that can quantify and qualify road hazards along roadways. Initially, relevant raw data can be collected from commercial vehicles by camera and DTG. Well-processed data, such as potholes, road freezing, and fog, can be generated from the Integrated management system. Road hazard algorithms combine these data with road inventory data in the Data Sharing Platform. Depending on well-processed data, four different road hazard algorithms and their associated indices were developed. To test the algorithms, an experimental plan based on passive DTG attached in probe vehicles was performed at two different test locations. Selection of the test routes was based on historical data. Although there were limitations using random data for commercial vehicles, hazardous roadways sections, such as fog, road freezing, and potholes, were generated based on actual historical data. As a result, no algorithm error was found in the entire test. Because this study provides road hazard information according to a section, not a point, it can be practically helpful to road users as well as road agencies.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.61-68
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• 2013

PURPOSES : The purpose of this study is to study the noise reducing effect of Micro Surfacing by comparing general asphalt, longitudinal tining and Slurry Seal. METHODS : This study measures vehicles' noise of each section by the NCPX method that can measure noise between the road surface and the tire at the field. Total sound pressure and sound pressure level by the 1/3 octave band frequency are calculated through the field data of each section. Total sound pressure level is compared by ANOVA test statistically. After ANOVA test, post-hoc test is conducted to know mean difference of surface type by Tukey. RESULTS : As the result of CPB analysis to confirm sound pressure levels by frequency, it was shown that sound pressure levels by frequency are totally similar except for those of frequency bands between 100Hz and 500Hz. The result of ANOVA test and post-hoc test, it was shown that sections of surface type have a difference. The result of Micro Surfacing was lower 2~5dB(A) than other surface type. CONCLUSIONS : It is found that the noise reduction performance of Micro Surfacing was better than other surface type.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.9-17
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• 2018

PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS : The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mock-up test showed efficiency in the field and penetration resistance performance. CONCLUSIONS : The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

• Journal of the Korean GEO-environmental Society
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• v.24 no.1
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• pp.37-44
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• 2023

In this study, the performance of the support modular system, as substructure of the proposed sustainable-perpetual modular road system to reduce road construction time and maintenance costs was evaluated. A modular road system consisting of 4 support modular cross-beams with a lower curved surface was constructed on the test-bed. Six load cells and eight LVDTs were installed in the center part of two cross-beam support modular systems. Two loads, 50kN and 100kN, were applied to 15 points on the pavement slab to measure the load and displacement occurring in the modular road system. The measured displacements were less than 1 mm, so it is considered that there was no problem in the stability of the actual road. When comparing the two applied loads and the measured loads in the field test, it was considered that the load transmitted to the ground under the support modular system is very small. It is considered that the modular road system with the support modular system is applicable to the actual road site.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.47-56
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• 2015

PURPOSES: The purpose of this study is to estimate the impact of variable message signage (VMS) on traffic safety as a function of road curve radius using statistical methods. METHODS: In order to analyze the impact of VMS installations on traffic safety, travel speed, lateral distance, and geometric data relating to road curvature in each study area was acquired and analyzed for the impact of providing VMS information on driver performance and traffic safety using statistical methods including student t-test, Mann-Whitney test, and the Anderson-Darling test for estimating traffic safety hazard zone in each lane. RESULTS: As a result of analyzing driver performance characteristics before and after providing VMS information, it was determined that by providing VMS information, mean travel speed is deceased and vehicles are driven with increased precision, following the centerline in the first and second lanes. Also the results of analyzing traffic safety impacts of VMS indicate that traffic safety performance factors in the first lane of the Gapyeong section can, on average, increase in the left and right side of the lane by 19.22% and 68.98%, respectively, and in the case of the second lane, safety impacts, on average, can increase in both sides by 100%. For the Hongcheon section, traffic safety impacts in the first lane, on average, can increase along the left and right sides of the lane by 32.31% and 47.18%, and within the second lane, traffic safety can be increased along the left and right side of the lane by 10.97% and -0.01%, respectively. CONCLUSIONS: Based on the results of this study, the impact on traffic safety obtained by providing VMS information for road sections with smaller curve radii is greater than can be obtained for road sections with larger curve radii.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.35-43
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• 2008

This paper mainly deals with the performance evaluation of 33 asphalt sections of Korea Expressway Corporation Test Road (KECTR) during the past four years. Since the construction of the KECTR in December 2002, key performance indicators of asphalt pavements have been collected five times with an Automatic Road Analyzer (ARAN), and have been analyzed for permanent deformation, surface distress, and road roughness. Linear viscoelastic characteristics of four dense graded HMAs used in KECTR were investigated with a series of complex modulus test. The effect of air void in HMAs on dynamic modulus was investigate at two air void contents for a surface course HMA (19 mm Nominal Maximum Size of Aggregate). Layer densification due to traffic was estimated from air void contents of field cored samples, and was correlated with pavement distresses and performances. One of findings of this study was that both permanent deformation and cracking were suspectible to pavement temperatures, rather than traffic. However, it was found that road roughness was mostly affected by traffic loading.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.541-546
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• 2006

Recently, slope failures are happen to natural disastrous when they occur in mountainous areas adjoining highways in Korea. The accidents associated with slope failures have increased due to rapid urbanization of mountainous areas. Therefore, Regular maintenance is essential for all slope and needs maintenance of road safety as well as road function. The purpose of this paper is to recommend a standard of a $N_{10}^{\sim}$ value of Distribution of a potential failure layer using PPT(Portable penetration test).

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.47-57
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• 2007

The vibration environment essentially companied by vehicle operation on the road is determined by the shape of road surface, which is called profile. In general, the profile and severity of unpaved road is an important issue in the reliability of durability test for vehicles. In order to maintain severity of unpaved road, it is necessary to develop profilometer system. We developed profilometer system which is composed of data processing computer, power unit, air compressor and sensors. This paper focuses on the severity management of unpaved test courses using neural networks. This paper presents the maintenance range for cross-country course in CPG(Chang-won Proving Ground) and the evaluation of similarity degree between unpaved roads.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.581-586
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• 2014

In general vibration test considers both harmonic vibration and random vibration, When developing the vehicle component. But the effect of harmonic vibration is larger in the parts around the vehicle engine, sole testing the harmonic vibration is considered. In this study, the fatigue damage of the linear system fixed around the engine is analyzed when the effect of random vibration is higher, harsher than the normal road surface condition. In condition the vehicle speed and the engine RPM are similar, the higher the harshness of the road surface condition is, the larger the fatigue damage level is. Therefore both random vibration and harmonic vibration must be considered in vibration test of components around the engine. Proposing the sine on random(SOR) vibration test that can exam considering both of vibrations, harmonic and random.