Jakarta, the capital city of Indonesia, is home to 10 millions of Indonesia population. Recently the Indonesian government is being sued by a group of activists and environmentalists due to the unhealthy air quality in Jakarta. The plaintiff hopes that through the lawsuit, the Indonesian government can improve existing policies to address the air pollution issues.
On 18 Jul, according to the Switzerland-based pollution mapping service AirVisual, the Air Quality Index (AQI) of Jakarta is 153, categorized as unhealthy and may cause increased aggravation of the heart and lungs. The recommendation upon this condition is to wear a pollution mask and use air purifiers inside the room. The AQI Measures five criteria air pollutants (particulate matter, sulphur, dioxide, carbon monoxide, nitrogen dioxide, and ozone), and converts the measured pollutant concentration in a community’s air to a number on a scale of 0 to 500.
Jakarta is one of the largest urban agglomerations in the world. The uncontrolled increase in urban population is proportional to the number of the vehicle in Jakarta. According to Badan Pusat Statistik (Statistics Indonesia), the growth of motorized vehicle in Jakarta is 5,35% every year, on the other hand, this growth will increase the number of pollution in Jakarta. This statement is supported by the acting head of Jakarta Environment Agency, Andono Warih, the fuel residue of motorized vehicles was the main contributor to severe air pollution as 80 per cent of vehicles powered by diesel fuel operated from Jakarta Greater Area (Jabodetabek) to the capital.
Jakartan can contribute directly to overcome air pollution issues. Public transportation is an environmentally friendly mode of getting around. Because public transportation carries many passengers on a single-vehicle, thus it can reduce the number of vehicles as well as reducing the number of emissions from transportation in a dense urban area. Further, public transportation can help Jakarta to reduce the smog, to meet air quality standards and to decrease the health risk of unhealthy air quality.
The urban transportation system in Indonesia consists of buses, trams, light rail, metro, rapid transit and ferries. Particularly in Jakarta, urban rail-based transportation, such as Commuter Line Train, Light Rail Transit (LRT) and Mass Rapid Transit (MRT), provides mobility and access to the urban area.
The first phase of MRT Jakarta (MRT-J) has been operating since March 2019. In daily operation, the train runs from Lebak Bulus Grab Station to the Bundaran HI Station. There are 13 stations along the railway; the underground stations are Bundaran HI, Dukuh Atas BNI, Setiabudi Astra, Bendungan Hilir, Istora Mandiri, and Senayan Station. Meanwhile, the overground stations are ASEAN, Blok M, Blok A, Haji Nawi, Cipete Raya, Fatmawati, and Lebak Bulus Grab Station. The MRT-J only needs 30 minutes to travel along the 16 kilometres railway, starting from Lebak Bulus Grab Station in South Jakarta to the Bundaran HI Station in Central Jakarta.
There are 16 train lines available to take the passengers getting around. Based on the MRT-J website, In weekdays operation, the trains operate at 05.00 WIB to 24.00 WIB with a total of 285 trips. Meanwhile, in weekend operation, the trains run at the same hour with a total of 219 trips.
During the promo operation (1 April – 12 May), the average number of daily passengers reached 82,643, whereas after the full tariff was applied, the average per day was 81,459.
The following pictures will show you the scenes of MRT Jakarta.
So what do you think? Have you tried getting around using MRT Jakarta? If you have never, try immediately and feel the different sensation of Public Transportation in Indonesia.
Further, through this article, I would like to invite you, explore the MRT Jakarta through a different perspective, that may be for a group of people this method is still rarely used, a sound.
Do you realize that sound can tell us about character, place, and time? Sometimes, it informs us in ways visuals can’t, and that is the idea of what we are going to do right now. Later you will hear, a file of recorded sound of MRT-J in its daily operation.
The sound was recorded by the soundwalk method, any excursion whose primary purpose is listening to the environment. It is exposing our ears to every sound around us no matter where we are. We may be at home, walking across a downtown street, or even at the office. Meanwhile, in this case, our environment is inside the line of MRT Jakarta. The goal is to capture any sound sources that exist during the operation of MRT-J, including the activity of the passengers.
The sound was recorded by using a mounted microphone on the iPhone X at a level of 1.2 m above the ground. The following sound is a recorded environment while the MRT-J was travelling from Bundaran HI Station to Setiabudi Astra Station, the duration of recording sound is 4 minutes and 40 seconds. Please use an earphone or any similar devices to listen to the audio for a better experience.
After listening to the sound, can you identify what sound sources are presented in the recording? Here are the sound sources that I have identified:
- Engine sound increases speed
- Public Address system
- Engine sound
- Rail friction
- Passengers’ activities (cough, sneeze, conversation, footsteps, etc.)
- The sound of the door opening
- Brake squeak
Now we have identified the sound sources that are presented in the recording. But, do you know how many decibels that I have to endure while travelling using the MRT-J? In this article, manual measurements of noise levels were performed with a sound level meter in the MRT Jakarta with passengers on its usual route. A-weighted sound level measurements were recorded directly from one station to the next during the time between 08:00 and 09:00, using a calibrated microphone on a stand at a level of 1.2 m above the ground. The results of equivalent continuous A-weighted noise levels Leq (LAEq) in the MRT-J with passengers on its usual route from one station to the next is shown in Chart 1.
Leq is the A-weighted energy means of the noise level averaged over the measurement period. The results from the measurements show that the A-weighted noise level is varied between 77 dB to 82 dB. Further, if we look closely into the Chart, the noise level is fluctuating. It can be caused by a lot of factors, such as:
- The position of MRTJ (When MRT-J inside the tunnel, the noise can be levelled up due to the reflection phenomenon).
- Speed (The machine indicates producing a higher noise when in the maximum speed).
- Path Crossing.
- The Public Address System Volume.
Moreover, the level of continuous noise in Chart 1 represents a quite noisy environment. According to The National Institute on Deafness and Other Communication Disorders, states that Long or repeated exposure to sound at or above 85 dB can cause hearing loss. Thus, according to the measurement results, I suggested you wear ear protection during commuting by MRT-J. The earplug is one of the equipment that we can use to protect our hearing; you only need to spend a few thousand rupiahs for this. Wearing earplugs can help you to reduce the noise by 18 – 34 dB, it depends on the models/brand. For more accurate results, we need to do a complex measurement, such as:
- Add measurement point (In this article, the measurement was done only in a measurement point, at the second car of the line).
- Add a velocity as a measured parameter.
- Add the measurement time; the measurement can be done during the operation hour, non-stop. (05:00 – 24:00 WIB).
Nonetheless, the idea of showing the measurement results is spreading noise awareness. Noise sticks with you around, even common sounds you hear at work or home can contribute to long term hearing loss and other health risks, they are everywhere, but only a few people are aware of it. Noise pollution is a health threat nobody is talking about. Here are some parameters to help you determine acceptable — and dangerous — noise levels:
- 45 dB: nightly noise ordinance threshold set by many municipalities concerned with industrial noise exposure for residents
- 65 db+: exposure for prolonged periods can cause physical and mental fatigue
- 85 dB+: can cause permanent hearing loss if exposed for extended periods
- 85-120 dB: dangerous over 30 minutes of exposure
- 120-130 dB: can cause permanent hearing loss for exposure over 30 seconds
- 130 dB+: not only are these noises painful, but hearing protection should always be used if avoidance is not possible.
Everyone needs to take care of their ears and hearing, as damage to the auditory system could be irreparable. The loss because of the noise exposure is gradual; you might not notice the signs, or you ignore them until they become more apparent. Please do protect your ears.
Westerkamp, Hildegard (1974). “Soundwalking”. Sound Heritage