九州大学学術情報リポジトリKyushu University Institutional Repository

二輪車のパワーレベル（インドネシアMakassar市における測定）

フスティム, ムラリア九州大学大学院人間環境学府空間システム専攻博士後期課程

藤本, 一壽九州大学大学院人間環境学研究院都市・建築学部門

Hustim, MuraliaDepartment of Architecture, Graduate School of Human-Environment Studies, Kyushu University

Fujimoto, KazutoshiDepartment of Architecture and Urban Design, Faculty of Human-Environment Studies, KyushuUniversity

https://doi.org/10.15017/26773

出版情報：都市・建築学研究. 22, pp.91-96, 2012-07-15. 九州大学大学院人間環境学研究院都市・建築学部門バージョン：published権利関係：

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J. of Architecture and Urban Design, Kyushu University, No.22, pp. 91~96, July. 2012

Power Level of Motorcycle in Makassar City, Indonesia

A 7 1)7·7/..71 A*, Jfi*~=#**

Muralia HUSTIM* and Kazutoshi FUJIMOTO**

Since the traffic behavior is heterogeneous and the number of motorcycle (MC) is dominant on the roads at Makassar

City in Indonesia, to grasp the characteristic of the road traffic noise (RTN) such as the power level of the MC is

needed when predicting the RTN at roadside areas in Makassar City. This paper shows the sound power level of the

MC in Makassar City. The measurement of power level of MC is_ carried out at three roads in Makassar City. The peak

level and the speed of vehicle ate measured to obtain the power level for MC. 425 data for MC with the dominant size

of engine of 11 Occ and the speed between 20-40km/h are measured. The statistical analysis shows the power level has

a good relationship with the speed. The results follow the trend of the power level in steady condition presented in the

ASJ RTN-Model 2008 when the speed of vehicle is under 40 km/h. It coincides with the authors' previous research

work. The prediction of the RTN by using the power level of motorcycle obtained in this paper provides more precise

noise value.

Keywords: Road traffic noise, Power level of motorcycle, Makassar City

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l. Introduction

1.1 Background

Nowadays, in many cities in Indonesia, one of the Asian

developing countries, the environmental quality is gradually

degrading due to the rapid increase of the number of

vehicles. This leads the increase of the road traffic noise

(RTN) in the cities. To develop the prediction model of the

R TN and establish a noise policy becomes an urgent issue in

Indonesia to abate the RTN.

Regarding to the above condition, the authors conduct a

research on the issue of the RTN in order to find optimal

solution for the problem of the RTN focusing Makassar City,

whieh is one of the largest cities in Indonesia. In order to

achieve the main aim of the research, the authors conduct

three steps · research in three years, based on the reference

scheme conducted in Japan. In this context, the steps of the

research are to grasp the present condition of the RTN in

Makassar, to construct the GIS of the RTN in Makassar, and

to examine how to reduce the RTN in Makassar City. The

outputs of the research ,consist of the present condition of the

RTN, Makassar noise map, and guidelines for the reduction

measures of the RTN in Makassar City.

*

**

Department of Architecture ~FFliY.AT L:W::0(tf±1~Wi~*f~ Department of Architecture and Urban Design Wri1·~~~if~P~

As the first step, in order to grasp the present condition

of the RTN in Makassar City, the authors have performed a

noise survey at thirty-five main roads which almost cover

the whole areas in Makassar City r1H2l. The results show that

the noise levels at roadside of these roads is very high and

the average value is 74dB from morning until evening. This

value exceeds the highest value of the Environmental

Standard for Noise in Indonesian. In addition, motorcycles

dominate the traffic fleet whereas heavy vehicles are very

few. As a result of such conditions, the average speed of the

vehicles is less than 40km/h, a low speed category.

Nevertheless, the traffic flow seems still in steady state

condition. Due to the above condition, the drivers generate

the horn many times to keep safety; the time of horns widely

changes from 13times/1 Ominutes to 149times/1 Ominutes.

The authors predicted equivalent continuous

A-weighted sound pressure level in a day (LAeq,day) assuming

the non-steady traffic condition by using the ASJ

RTN-Model 2008 Pl. However, it was found that all the

predicted L Aeq,day are greater than the mea~ured ones. This

· suggests the necessity to explore the cause and take them

into consideration for a good prediction of the R TN.

Therefore, the authors try to elaborate some efforts to

find a good prediction of LAeq,day· The first is to consider the

actual traffic condition. The traffic should be assumed to be

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(a) Tanjung Street (b) Hasanuddin University Street

Fig. I The roads for measurement

(c) Baddoka Street

steady traffic flow at low vehicle speed. The second is the

effect of the horns sound which apparently influences the

noise level. And the last is the power level of motorcycle

which the dominant traffic in Makassar City.

On the point of traffic flow, the authors predicted

L Aeg,day assuming steady traffic flow and the actual vehicle

speed condition (28 km/h) based on the ASJ RTN-Model

2008 and the difference between predicted L Aeg,day and

measured ones is 2.33 dB on average [4l_ This result is

reasonable and better than the previous one when non-steady

traffic flow is assumed. Then, in order to improve the noise

prediction, the authors tried to examine a method to take the

effect of horns on noise level into consideration [4l _ When

considering the effect of horn sound, the power level of horn

sound is a problem because it is not shown in the ASJ

RTN-Model 2008. The authors imitated the Asakura's

method rsi, and as a result we could make the predicted of

L Aeg,day close to the measured value. To verify this method to

consider the effect of horn sound on the RTN, we carried out

two additional noise surveys (2nd and 3rd surveys) in

Makassar City. The results in these two surveys verified the

validity of the proposed method to consider the effect of

horn sound on RTN.

However, for predicting road traffic noise more

precisely, to grasp precise power level of horn sound and

vehicle, especially for motorcycle, is needed. The authors

tried to grasp the acoustic characteristics as well as the

power level of horn sounds [6l. The acoustical measurement

is performed in 2nd and 3rd surveys. Open and quiet place

was selected as a measuring point in the campus of

Hasanuddin University .in Makassar City. The power level

and the frequency characteristics for motorcycles and light

vehicles are obtained by using test vehicles. As a result, it

was found that the characteristics of horn sounds are not

always stable (the characteristics of horn sounds might be

different for each horn) and it can be thought that the

characteristics of horn sounds should be grasped statistically.

Further examination and survey to grasp . the

characteristics of the RTN's component such the power level

of vehicle is needed [7]' because the motorcycle is dominant

vehicle in Makassar City and the type of motorcycle in

Makassar is difference from Japanese motorcycle. On this

background, the authors focus on the sound power level of

the motorcycle in this paper.

1.2 Object

On the above background, this paper aims to grasp the

sound power level of motorcycle in Makassar City,

Indonesia.

2. Measurement of Motorcycle's Power Level

2.1 Method

In order to grasp the power level of motorcycle in

Makassar City, 4th survey was carried out. That survey

focus on a measurement of power level of motorcycle. Three

roads; Tanjung Street, Baddoka Street and Hasanuddin

University Street, were selected for the survey in Makassar

City. These roads were fit to the criteria for the measurement

of power level. That is, they were open and quiet areas to

escape from the effect of background noise. Ambient noise

levels at the sites were less than 35dB. Also the roads were

straight to allow the vehicle to pass through with a constant

speed. And number of traffic is very small to enable us to

measure each target vehicle sound separately. Fig. I shows

the roads for the measurement.

The measuring arrangement is shown in Fig.2. The

markers were set at points A and B with the distance of 20m,

and the measurement point was set in the center of AB.

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10.0m +

Vehicle

LA,max (dB)

10.0 m

···········.,.,

Speed Gun V (km/hour)

Fig.2 The measuring arrangement

Width of road

(m)

Sound level meter (SLM) was set at the position with the

distance of I.Om from the road edge and height of l.2in

above the ground. And A-weighted sound pressure level was

observed when only one vehicle was passing through zone

AB at the measurement point by SLM (RION NL-32) and

LAmax (peak level while a vehicle is passing through zone

AB) was measured.

The speed of vehicle ( V [km/h]) was measured by a

speed gun and the distance from the measurement point and

the vehicle (d [m]) were also measured.

2.2 Calculation of Power Level of Vehicle

Table 1 shows the number of data obtained in the

measurement. As is found here, the number of data for the

speed vehicle between 20-30km/h and 30-40km/h is

dominant than the others. On the contrary the data for more

than 60km/h are very small, this shows the actual situation

of road traffics in Makassar City. The average speed of the

·vehicles is less than· 40km/h, this agrees with the result of

the authors' previous survey. Considering another side, the

majority of engine type of motorcycle is 1 lOcc and the

percentage of thedata is 85%.

Then A-weighted power level of vehicle Lw is

calculated by Eq.(1)

Lw = LAmax + 201og10d + 8 (1)

Here, d is the distance between a sound source and a

measuring point.

3. Result and Discussion

3.1 Result

After calculation of the power leveJ, we made the

distributions of them for each 1 Okm/h band in speed and for

each type of vehicle engine of motorcycle. Here the data for

Table 1 Number of data

Speed of vehicle Type of Motorcycle (cc) (km/h) 110 125 135 150

10-20 10

20-30 121 8 2 2

30-40 140 8 8 7

40-50 70 6 4 8

50-60 19 3 1 3

60-70 1 1 1 1

70-80 1

Total 362 26 16 21

the speed more than 60km/h and the type of engine other

than 11 Occ are ignored because the number of data is very

small. The authors focus on the motorcycle data with the

speed between 1 Okm/h until 60km/h and type of engine only

1 lOcc to determine the motorcycle's power level.

Fig.3 shows the distributions of power level. It is

clearly found that power level distributes widely in each

speed band. Therefore, a selection of data is needed to make

the data more precise. After some examinations, the authors

resulted in adopting the data of 80% range as effective data

for the subsequent analysis. Dark bars show selected data in

Fig.3.

3.2 Relation Between Lw and V

Fig.4 shows the relationship between vehicle power

levels of the selected data and vehicle speed of motorcycle.

Curve lines show the regression lines assuming that Lw

has a relationship of Eq.(2) with V. In spite of the selected

data, Lw still distributes widely around the regression curve

as found in Fig.4.

Lw= a+ blogV (2)

Then, energy-averaged levels in each speed band were

calculated, and the relationship between averaged Lw and V

was analyzed again. The results were shown in Fig.5 and

regression coefficients a and b are shown in Table 2. The

results show that Lw has a good relationship with V.

Table 2 Result ofregression analysis

Regression Correlation coefficient coefficient

a b r

All data 67.8 17.1 0.676

Average data 67.7 17.4 0.987

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40 ~----------------.

30

30

Motorcycle (MC) N= 10 N(80%) = 8

2oo~~s~IB~~m@m~ffi~~ffi~~ffi ~@~~~s~~~~ffi@~~~~~~~ffi

Lw (dB)

a) V= I0-20km/h

Motorcycle (MC) N= 121 N(80cYo) 98

Lw (dB)

b) V = 20 - 3 0 km/h

40 ~------------------.

30

Motorcycle (MC) N= 140 N(80%) = 114

Lw (dB)

c) V= 30 40 km/h

40 --------------~

30

10

0

30

Motorcycle (MC) N=70 N(80%1)=56

Lw (dB)

d) V= 40- 50 km/h

Motorcycle (MC) N 19 N(80%)= 15

Lw (dB)

e) V = 50 - 60 km/h

Fig.3 Distribution of lw

3.3 Comparison with ASJ RTN-Model 2008

The results obtained in 3.2 were compared with the ASJ

RTN-Model 2008 l3J_ Here two traffic conditions; steady and

non-steady traffic flow conditions, were examined in

comparing with the ASJ RTN-Model 2008.

Fig.6 shows the comparisons between the author's result

and the ASJ RTN-Model 2008. In this figures, black curve

shows power level in steady traffic condition in the ASJ

RTN-Model 2008 and dashed curve shows the expansion of

its which is not guaranteed by the ASJ.

It can be found that power level obtained in this paper

follow the trend of steady condition of the ASJ RTN-Model

2008 when the speed .of vehicle is under 40 km/h for

motorcycle.

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110

$ 100 -0 "-"

~ ~ 90

80

70

120

110

,.-.._ 100 co -0 "-"

90

80

10

Motorcyc1e

•

Lw =67.8+17.I Log v r = 0.676

N =290

20 . 30 40 60

V(Km/h)

Fig.4 Relationship between Lw and V

Motorcycle

•

Lw = 6 7. 7 + 1 7 .4 Log v r = 0.987

N=5

100

70 _._~~~~--~~--.~--.-~~~...--~---1,

10 20 30 40

V(Km/h)

60

Fig.5 Relationship between energy-averaged

100

Although the power level of motorcycle in Makassar is

appropriate to that of the ASJ Model when traffic is in steady

condition, it is larger than that ofASJ Model when the speed

of the motorcycle is lower than 30 km/hour. Meanwhile, the

power level of Makassar's motorcycle is below than that

ASJ Model when the speed more than 30 km/hour. This can

be understood by considering that most of motorcycles in

Makassar have about 11 Occ of engine, while 50cc is

dominant in Japan.

As is well known, motorcycle with low engine size

produces small noise when the speed is low, and louder

noise is generated as the speed increase. On the contrary,

motorcycle with high engine size produces high noise even

. the speed is low.

Lastly, the result of the measured Lw is similar to the

value calculated by the ASJ RTN-Model 2008 assuming that

traffic flow is steady, coincides with the consideration in our

previous research work [41.

3.4 Applying the Power Level of Motorcycle to Predict

theRTN

In order to verify the validity of power level of

motorcycle obtained in 3.3, the authors apply the power

level of motorcycle to predict the traffic noise level (LAeq,day).

The RTN prediction is based on the ASJ RTN-Model 2008

under steady traffic condition and actual speed of vehicle (28

km/h) [SJ when the power level obtained in 3 .3 is used for

motorcycle. The comparison between predicted LAeq,day and

measured ones are shown in Fig. 7 and Fig.8.

Fig.7 shows the prediction by using ASJ's power level

of motorcycle (93.1 dB). It was found that the predicted

LAeq,day are smaller than .the measurement ones. The

difference between them is 2.33 dB on average.

Whereas, Fig.8 shows the prediction by using

measured power level of motorcycle (92.8 dB). The result is

generally same with the Fig. 7 although the difference

between them is 2.53 dB on average .

Overall, the prediction results as shown in Fig.7 and

Fig.8 are almost same. This is because although the power

level of motorcycle obtained in this paper is difference with

.the power level by ASJ RTN Model 2008, but. both power

levels are mostly similar at the speed of vehicle 28km/h.

75 -t-~-r-~~r-~-.--~-.,-~~-..-~--.--~--1

0 10 20 30 40 50 60 70 V(Kmlh)

Fig.6 Comparison of measured and caiculated Lw

-95-

85

80 ,--.._ t:C1 '"O '-"

~ 75

""d a (].)

-< 70 • .....:i ""d

(].) !-< ;:::::)

65 VJ ro (].)

:E 60

N =35

55 60 65 70 75 80 85

Predicted LAeq,day (dB)

Fig.7 LAeq,day by ASJ's power level of motorcycle

4. Conclusion

A-weighted sound pressure level emitted from a single

motorcycle running at the actual road in Makassar City was

measured and the power level is examined in order to grasp

the power level of motorcycle more precisely in Makassar

City, Indonesia. The relation between the power level and

the speed was analyzed and compared with the ASJ

RTN-Model 2008.

The results show that the relation between the power

levels and speed correlate significantly to their speeds. The

power level follows the trend of steady condition of the ASJ

RTN-Model 2008 when the speed of vehicle is ·under 40

km/h. This result coincides with our previous work.

Although the power level of motorcycle in Makassar

City is almost same with that presented by the ASJ when the

speed is 28km/h which is an actual speed in Makassar City,

the power level that obtained in this paper is appropriate to

use in Makassar's RTN prediction than that of the ASJ

Model, because of the difference type of engine between

Makassar's motorcycle and Japanese one.

85

80 ,--.._ t:C1 ""d '-"

>-. 75 ro '"O" er (].)

-< 70 • .....:i ""d

(].) !-< ;:::::)

65 VJ ro (].)

:E 60

N=35

55 60 65 70 75 80 85 Predicted LAeq,day (dB)

Fig.8 LAeq,day by measurement power level of motorcycle

References [l] Muralia Hustim, Ken Anai, Kazutoshi Fujimoto, "Survey of

Road Traffic noise in Makassar City in Indonesia: Effect of Horn on Noise Level," ALT Kyushu Chapter Architectural Research Meeting, 2011.

[2] Muralia Hustim, Ken Anai, Kazutoshi Fujimoto, "Survey on road traffic noise in Makassar City, Indonesia," Proceedings of inter-noise 2011, Osaka Japan, September 4-7 2011

[3] Research Committee of Road Traffic Noise in the Acoustical Society of Japan,"Road traffic noise prediction model ASJ RTN-Model 2008,"Acoust. Sci. & Tech. 31 (1 ), pp.2-55 (2010).

[4] Muralia Hustim, Kazutoshi Fujimoto, "Road Traffic Noise under Heterogeneous Traffic Condition in Makassar City, Indonesia," Journal of Habitat Engineering and Design, 4( 1 ), March 2012.

[5] Takumi Asakura, Shinichi Sakamoto, Mafizur Rahman, "Noise measurement in Dhaka city,"Proceedings of the 2010 Autumn Meeting, The Institute of Noise Control ~ngineering ofJapan, pp.15-18 (2010) (in Japanese).

[6] Muralia Hustim, Kazutoshi Fujimoto, "Acoustical Characteristics of Horn Sound of Vehicles," Journal of Architecture and Urban Design, Kyushu University, (21 ), January 2012. .

[7] Muralia Hustim, Kazutoshi Fujimoto, "Power Level of Vehicles in Makassar City, Indonesia" AIJ Kyushu Chapter Architectural Research Meeting, 2012.

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