The Effect of Traffic Characteristics on Noise Level in Padang City

The purpose of this research is to: 1) identify the characteristics of traffic flow in Padang City, 2) analyze the traffic noise level, and 3) analyze the effect of traffic characteristics on the noise level. Measurements of traffic flow and noise levels were carried out at 14 points on weekdays and holidays using a Sound Level Meter. Analyses used were descriptive statistics, interpolation (GIS), and multiple linear regression. The results showed: 1) Traffic flow characteristics ranged from 412 to 7,530 vehicles per hour on weekdays, and 363 to 7,440 on holidays. 2) The noise level ranges from 65.2-84.8 dBA. 3) The coefficient of determination (R2) of 0.667 on weekdays and 0.633 on holidays shows that motorcycles, light vehicles, and heavy vehicles have an effect of 66.7% on weekdays and 63.3% on holidays. Heavy vehicles have the highest influence of all.


INTRODUCTION
In urban places, traffic noise is a typical issue.In addition to increasing congestion, the increase in highway traffic has an effect on air and noise pollution.The sound produced by vehicle engines, exhausts, tires, and horns at a certain level can interfere with comfort which is called noise or noise pollution [1].The usage of larger, more powerful machinery and the rapid expansion of transportation will produce audible noise that will endanger human life.
Currently, traffic noise levels in urban areas range from 70 to 80 dBA at a distance of 15 meters from the road [2].At this level, most people will be affected, disrupting concentration, conversation, and even increasing heart rate.The World Health Organization (WHO) states that traffic noise can affect people's lives and have negative impacts on their health, including hormonal changes, high blood pressure, headaches, and sleep problems.Both work productivity and learning motivation may be impacted by noise.Particularly at night, noise is deemed hazardous since it might shorten the quantity and quality of sleep [3].As a result, noise has an influence on human health and over time may actually harm health.
The Ministry of Environment in Indonesia has set the permissible level in certain areas called the Standard Noise Level [4].The standard level is a tolerable quantity or value expressed in decibels A (dBA).This regulation can be a 2 benchmark for how severe the level of incidents that occur in places such as schools, hospitals, places of worship, and so on.Therefore, evaluating the level of traffic in the area mentioned above is very important in the efforts to control and protect the environment.
In general, the number increases with the increase in traffic volume, vehicle speed, and passing trucks.The city of Padang as the capital as well as the center of the metropolitan area in West Sumatra Province has a fairly heavy traffic condition.According to the Central Statistics Agency of Padang City, the number of motorized vehicles in 2020 will reach 356,359 units [5].This condition causes Padang City to have occurred in the past and therefore, it is necessary to measure levels, especially in vulnerable areas in Padang City.The purpose of this research is to: 1) identify the characteristics of traffic flow in Padang City, 2) analyze the traffic noise level, and 3) analyze the effect of traffic characteristics on the noise level.

METHOD
The population in this study is all designation of the area/environment of activities in the city of Padang.As many as 14 spots were sampled on purpose.The sampling was based on the criteria for the categorization of the area/environment of activities outlined in Ministerial Decree No. 48 of 1996.Furthermore, the distribution of locations in Padang is taken into account.The distribution is as follows: Table 1 The spatial distribution can be seen in the following figure.

Noise Level
The noise level in question is a measure of sound energy expressed in units of decibel A (dBA).

Data Collection and Analysis Techniques
Measurement of traffic flow and noise level was carried out at 14 points on weekdays and holidays using a Sound Level Meter.Data analysis techniques used descriptive statistics, interpolation analysis (GIS), and multiple linear regression.Where the increase in the number of motorcycles on weekdays and a decrease on holidays.

The Level of Traffic Noise
During weekdays, the intensity of traffic noise at the measuring place ranges from 66.8-84.8dBA, while on holidays, it ranges from 65.2-84.8dBA.On weekdays, the average noise level is 74.5 dBA in the morning, afternoon, evening, and night, respectively.During the holidays, the values are 73.1, 75.0, 75.3, and 75.5 dBA.The maximum noise is discovered at night in the Semen Padang Hospital area, both on holidays and weekdays, with a value of 84.8 dBA, while the lowest is found in the Pasar Raya region on weekday mornings with a value of 66.8 dBA and on holidays with a value of 65, 2 dBA.Spatially, the map above shows that the highest noise on weekdays is around Semen Padang Hospital.These locations have noise levels ranging from 75 to above 80 dBA.Followed by Pasar Lubukbuaya with a noise level of 70 to 80 dBA.Meanwhile, the locations with the lowest traffic noise levels on weekdays are Pasar Raya and Imam Bonjol RTH with a noise level of 55 to 60 dBA.
While the next map shows the level of traffic noise on holidays in locations such as Semen Padang Hospital and Pasar Lubukbuaya, which is still the highest point of traffic noise.Noise levels range from 75 to above 80 dBA.For the highest noise level, there is no change if you look at the previous traffic noise level map, it is still in the two locations.As well as the location of the lowest traffic noise level, such as in Pasar Raya and Imam Bonjol green open space, there is also no significant change, ranging from 60 to 70 dBA.
From the above equation it can be concluded that the noise value on weekdays will change by 0.001478 per unit of motorcycle, 0.002637 per unit of light vehicle, and 0.017067 per unit of heavy vehicle.On holidays, the noise value will change by 0.001981 per unit of motorcycle, 0.000493 per unit of light vehicle, and 0.025392 per unit of heavy vehicle.In other words, the noise level on weekdays will increase by 1dBA if the number of motorcycles increases by 677  The results of the p-value of data processing obtained p <0.05 which indicates that the value of the variables on holidays are all significant, while on weekdays there is 1 insignificant variable, namely light vehicles of p = 0.48, which means that the noise generated light vehicles on weekdays is not significant or does not significantly affect the noise that occurs in traffic.
The relationship between noise levels and variables that affect noise is directly proportional, which means that the larger or more vehicles, the greater the noise produced.The value of the correlation coefficient (r) obtained on weekdays is 0.816703 and on holidays is 0.796067 which can be categorized as a strong correlation.Furthermore, the value of the coefficient of determination (R 2 ) obtained is 0.667 on weekdays and 0.633 which means that motorcycles, light vehicles, and heavy vehicles have an effect of 66.7% on weekdays and 63.3% on holidays, the rest is influenced by variables residue/error.From the linear regression equation obtained, it is found that heavy vehicles have the greatest coefficient or influence on the noise produced.Padang Hospital region has the highest noise, whereas Pasar Raya has the least.3. The relationship between noise levels and variables that affect noise is directly proportional, where the more vehicles there are, the greater the noise produced.The value of the correlation coefficient (r) on weekdays is 0.816703 and on holidays is 0.796067 which is categorized as a strong correlation.The value of the coefficient of determination (R 2 ) is 0.667 on weekdays and 0.633 on holidays, which means that motorcycles, light vehicles, and heavy vehicles have an effect of 66.7% on weekdays and 63.3% on holidays, the rest is influenced by residual variables / error.Of the three independent variables, the heavy vehicle variable has the highest influence on traffic noise.

Fig. 4 .
Fig. 4. Motorcycle on weekdays and holidays The graph above shows the comparison of the number of motorbikes on weekdays with holidays.Still happening at the same location, Pasar Lubukbuaya has the highest number of motorbikes, on weekdays it occurs at night and on holidays in the afternoon.Changes also occurred in the Masjid Raya Sumbar, there was a change in the number of motorcycles.Where the increase in the number of motorcycles on weekdays and a decrease on holidays.2.The Level of Traffic Noise

CONCLUSION 1 . 2 .
Traffic flow characteristics range from 412 to 7,530 vehicles per hour on weekdays.While on holidays it ranges from 363 to 7,440 vehicles per hour.The traffic noise intensity ranges from 65.2 to 84.8 dBA.The Semen

1 .
Traffic Characteristics Comparison of traffic characteristics on weekdays and holidays On weekdays, the highest volume of vehicles is in front of the Masjid Raya Sumbar, reaching 7,530 vehicles per hour.While the lowest is at Telukbayur Port with a volume of 412 vehicles per hour.Judging from the composition of vehicles, the highest volume of trucks is in front of the RS.Siti Rahmah during the day reached 567 vehicles per hour.Meanwhile, the highest volume of passenger cars is located in front of the Masjid Raya Sumbar, reaching 3,265 vehicles per hour.The highest motorcycles are in Lubukbuaya Market, 5,792 vehicles per hour.
On holidays it can be seen that the highest traffic volume (number of vehicles) is at Pasar Lubukbuaya, reaching 7,440 vehicles per hour.While the lowest is at Telukbayur Port with a volume of 363 vehicles per hour.Judging from the composition of vehicles, the highest volume of trucks is found at Semen Padang Hospital during the day, reaching 567 vehicles per hour.Meanwhile, the highest number of passenger cars and motorcycles is in Pasar Lubukbuaya with 2,315 and 5,850 vehicles per hour, respectively.

Table 3 .
The results of the regression coefficients for each variable.
per hour or 379 light vehicles per hour or 59 heavy vehicles per hour.Meanwhile, the noise level on holidays will increase by 1dBA if there are 505 motorcycles per hour or 2,028 light vehicles per hour or 40 heavy vehicles per hour.