• Journal of Environmental Health Sciences
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• v.34 no.5
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• pp.395-402
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• 2008

Road traffic noise causes considerable disturbance and annoyance in exposed inhabitants. Particularly, arterial road noise is a significant environmental problem in many urban areas in which higher traffic volume and higher car speed occur. Arterial road noise became the target of this investigation in Seoul, South Korea. Noise levels were measured at four points that were based on distance from roadside at the same measurement site and under the conditions as reported by the National Institute of Environmental Research (NIER) in 1999. The average noise levels ($L_{eq,1h}$) of the arterial road was 80.3 dBA at 5 m, 77.4 dBA at 10 m, 73.7 dBA at 20 m, 70.9 dBA at 30 m. A comparison between 1999 and 2008's measurement values has shown that in 2008 noise level is up by about 1.5 dBA, traffic volume has increased by about 15.7%, while car speed has decrease by about 8%. The relationship between 2008' measured values and predicted values using the NIER Equation is low under 10 m from the roadside. The influence range of arterial noise is calculated at 26 m for road noise limits in daytime. In relation to the comparison between traffic volume and noise level, the equivalence in traffic volume (Light car+10xHeavy car) is higher than other variables.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.500-504
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• 2008

Residents in an area where both trains and cars pass through are exposed to not only road traffic noise but also railway noise. Nevertheless, the degree of annoyance the caused to the residents is being under evaluated as the noises have been evaluated separately. Therefore, this study aimed at evaluating the integrated noise of road traffic and railway, and proving the accuracy of the evaluation result.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.635-644
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• 2005

This paper is. a study on relation between road traffic noise(RTN) and sound power level(PWL). At present, many experimental formulae and prediction formulae are used for prediction of RTN. But these formulae are difficult to appiy to the metropolitan area because these formulae are inaccurate in the different condition from reference condition. This paper calculate RTN and PWL of each prediction formula, choose the best one and make a noise map of the subject area. Procedure is as follows. First, calculate $L_{eq}$ of RTN using experimental formulae and prediction formulae. Second, calculate PWL using $L_{eq}$ of RTN and distance attenuation for point source at semi-free field. Third, choose the most accurate formula. And finally, make a noise map of the subject area at present and future. The result using noise map will be able to apply to application field. Noise mapping tool used on this paper is Raynoise program using Ray Tracing Method(RTM), Mirror Image Source Method(MISM) and Hybrid Method(HM).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.8
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• pp.581-588
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• 2002

Precise highway traffic noise simulation and reduction require the accurate data for sound power levels omitted by vehicles, varied to road surface, traffic speed, vehicle types and makers, different from countries to countries. In this study, we have elaboratively measured Korea highway traffic noise and parameters affecting noise levels at the nearside carriageway edge. From numerical simulation using the measured results for highway traffic noise, we propose not only two correction factors to enhance the accuracy of Korea highway traffic sound power estimation using ASJ Model-1998 but also its typical power spectrum according to road surface type. The measured and predicted highway traffic noise levels using the proposed sound power show little difference within 1 dB.

• KIEAE Journal
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• v.9 no.1
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• pp.61-68
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• 2009

In this study, computer simulation program was using to identify the effects of road traffic noise propagation depending on the road types which are very variable in dense city. To achieve this goal, the roads should adjacent to housing complex were categorized into 7 types and propagation noise level should predicted then after simulation of noise exposure population calculation are carried out. Followings the results. First, the road types producing the higher noise level are R1, R2, R3 and R7. The lowest one is R6. And R4, R5 showed that some amount of noise level reduction. Second. the R6 road type which is tunnel shaped showed the highest noise level reduction in vertical distance gap. Last, the order of noise exposure population ratio is R1>R2>R7 and R6 showed the lowest.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.782-785
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• 2004

In the Well-being age, many people use a city park for rest deeply think and constitutional walk. The city park is located at near side by traffic road in urban. Citizens are not satisfied with it's fuction as a haven of peace due to road traffic noise. Thus, this study is for a research on the actual noise condition of a city park in Nowon go. This study uses a prediction method called ASJ-model in order to calculate PWLs of road traffic noise. Using calculated PWLs, noise levels in a park are predicted and compared with measured values.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.101-104
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• 2007

All of noise prediction model have it's own features in the case of modeling conditions, so it is very important to know the features of each model case by case for a proper modeling, especially using at the Environmental Impact Assessment. For prediction of highway traffic noise and abating the noise by barriers, two kinds of prediction model, HW-NOISE, KHTN(Korea Highway Traffic Noise) has been mainly used in Korea. In this study, the features of these models were described at the same conditions. The properties of sound power from a road, diffraction characteristics from a barrier, sound pressure level decaying in each model were investigated. Using the results, it will be anticipated that the proper using of prediction models in the works of highway noise abating.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.1075-1082
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• 2009

Using GIS data of C-si as basic data when making noise map of road traffic, we estimated exactly the noise excess areas and consequently suggested the population and the area exposed to road traffic noise accurately. We made 3D noise map to assess regional distribution of noise quantitatively. The noise map consists of noise prediction model based on data base such as traffic volume and speed changes for estimating quantitatively the noise and 3D urban space model which includes locations of noise sources, 3D buildings, topography and roads. We made noise standard map according to land use conditions and compared this map to road traffic noise map, and consequently made excess noise map. Using excess noise map, we assessed areas which exceed environmental noise level standards and noise guidelines quantitatively and effectively through GIS spatial analysis, and consequently more accurate noise exposed area and noise exposed population could be estimated. To show buildings' outer walls noise exposure, we analyzed 3D urban noise distributions using 3D-analysis of GIS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.236-242
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• 2002

This paper presents some advanced and supplemental methods to enhance the accuracy In case of calculating geometric divergence attenuation, attenuation by multiple screening structures, ground attenuation at unflat surfaces of sound during propagation outdoors by the methods specified in ISO 9613-2. Moreover, a calculation method for considering short-term wind effect, specified in ASJ Model-1998, is also introduced. To verity the accuracy of adopted methods, we have carried out highway traffic noise prediction and measurement at tile twelve locations appearing representative road shapes and structures, such as flat, retained cut, elevated, barrier-constructed roads. From the results, we have confirmed the predicted results show good correspondence with the measured at direct, diffracted and reflected sound fields within 30 m from the center of near side lane.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.877-881
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• 2007

Recently, noise map is used widely by synthetic estimation method for noise reduction. For correct manufacture of noise map, selection of suitable noise prediction method is important. This study compares XPS31-133 with CRTN, RLS90 which are widely used by foreign commercial noise maps.