Road to clean air: How MTC buses can tackle Chennai’s pollution problems

Rising NO2 pollution and traffic in Chennai underscore the need for sustainable public transport options

Ramesh S, a resident of Perambur, stands at his local bus stop, waiting to start his daily commute. A beat-up Metropolitan Transport Corporation (MTC) bus, painted pink at the front and rear, arrives, emitting visible black smoke from its exhaust. The fumes and unpleasant smell make him cough.

In 2023-24, the average age of MTC buses was 9.61 years as opposed to the recommended 9 years. With the addition of a few new buses into the fleet in 2024, this improved to 7.56 years, yet the overall situation remains concerning. The new buses still run on fossil fuel and the MTC is yet to introduce more sustainable alternatives.

An earlier Citizen Matters article noted that as of May 2023, the oldest bus in the MTC fleet was 17.4 years old, according to data obtained under the Right to Information Act.

MTC buses play a crucial role in improving public transportation in Chennai, but they contribute to air pollution in two ways. Firstly, by operating over-aged buses and lacking technical staff to maintain them. Secondly, by not providing enough buses, thus forcing people to opt for private vehicles.

A Tamil Nadu Pollution Control Board (TNPCB) study indicates that while private vehicles are significantly more polluting than public transport, older buses tend to emit more pollutants. Moreover, the study pointed out that the most significant reduction in environmental impact from transportation can be achieved by shifting more trips to electrically operated public transport.


Read more: Does Chennai have enough buses for its commuters?


What is NO2 pollution and how does it affect us?

A recent Greenpeace study titled Beyond North’, which analyses nitrogen dioxide (NO2) levels in seven major Indian cities including Chennai, highlights the urgent need for better public transport options.

Nitrogen dioxide, or NO2, is a gaseous air pollutant composed of nitrogen and oxygen and is one of a group of related gases called nitrogen oxides, or NOx. These gases are produced when fuels are burned. That means that vehicles and energy generation from fossil fuels are important NO2 sources.

Road traffic consistently remains among the top three sectors for nitrogen oxide (NO2 and NO) emissions. The Greenpeace study found that Chennai’s annual NO2 levels in 2023 were twice the World Health Organisation’s health-based guidelines, with a daily average of NO2 concentrations regularly exceeding these limits.

Exposure to NO2 can increase the risk of asthma, airway inflammation, and respiratory issues. It also contributes to serious conditions like ischemic stroke, heart disease, and lung cancer.

No technical staff to maintain the buses

“Buses are crucial to strike a balance between meeting the public’s needs and protecting the environment,” says Divya Senthil, a Road Safety and Sustainable Mobility Consultant.

Pointing out how lack of technical staff recruitment affects the maintenance of buses and thereby contributes to pollution, Dhayanand V, General Secretary of CITU’s MTC wing says, “As the buses age, they require more maintenance. For the maintenance of buses, we need more technical staff. In the past 12 years, there has been no appointment of technical staff in MTC. In the last decade, around 600 technical staff have retired from MTC leaving more vacancies.  Qualified people are waiting for appointments on compassionate grounds, yet there has been no initiative to fill the vacancy.”

A government order dated October 25 2024 notes that MTC has a vacancy of 2,522 technical staff. 

“Like how private vehicles have fitness checks, the buses should also be tested regularly not only from a mechanical perspective but in terms of emissions, public comfort and convenience,” notes Divya.


Read more: MTC staff brave poor working conditions to keep Chennai buses running


The need for reliable public transport: The role of MTC buses

Ramesh has a daily commute that reflects a larger trend in Chennai. He works in Nandanam and leaves home around 8 am. While he prefers taking a bus, the long wait times, overcrowding, and unpredictable schedules of Metropolitan Transport Corporation (MTC) buses often push him to rely on his private vehicle. “Traffic is too heavy during peak hours, so I travel from Perambur to Anna Nagar metro station by two-wheeler most of the days. From there, I take the metro to Nandanam, and finally book a two-wheeler taxi to my office,” he explains.

When Ramesh moved to Chennai in 2023, he did not own a bike. However, he soon realised that having one made his daily life much easier. 

As private vehicle numbers soar, emissions are also rising. According to a Tamil Nadu Pollution Control Board (TNPCB) study, private vehicles contribute significantly more to air pollution than public transport. Graphic: Bhanu Sridharan

Rise in private vehicle numbers

The Greenpeace study draws attention to a troubling trend — data from the Ministry of Road Transport and Highways (MoRTH) reveals a steady rise in the number of motor vehicles registered in Chennai from 2010 to 2020. However, the number of MTC buses has remained largely unchanged. This imbalance is exacerbating Chennai’s pollution problems.

Private vehicle
Data from TNSTA via Opencity also shows a similar trend of rising private vehicle ownership from 2004 to 2018. Graphic: Bhanu Sridharan.

Substantiating this, Santhosh Loganaathan, an Urban Development professional notes, “In 2014, MTC had 3,800 buses, serving around 50 lakh riders per day. By 2024, ridership had dropped to 31.80 lakh daily, a shift largely due to the increased use of private vehicles. Even if we assume half of all the riders lost in the last 10 years moved to two-wheelers, we are looking at an increase of 10 lakh kilogram of CO2 emission per day.”

Ridership on Metropolitan Transport Corporation (MTC) buses has declined substantially during this time. The sharp decline in 2020-21 is likely due to the COVID lockdown. Data: MTC. Graphic: Bhanu Sridharan.

Globally, dips in ridership are seen when buses are unreliable or uncomfortable. In some European cities, even offering free bus rides failed to maintain ridership due to inconsistent service.

The Ministry of Housing and Urban Affairs (MoHUA) suggests that a city needs 60 buses for every one lakh people. “While cities like London have 100 buses per lakh population, Chennai has approximately 35 buses per lakh population. With Chennai’s population growing rapidly, the city needs a fleet of 7,000 buses to serve its residents adequately,” he adds.

What is MTC doing about it? 

MTC is aware of the growing need for more and better-maintained buses. Dr Alby John Varghese, MTC’s Managing Director, notes that the corporation is in the process of inducting 500 electric buses to augment the fleet, with an additional 600 e-buses set to join soon. This will boost the fleet size by 33%. MTC plans to gradually reach a fleet of 7,000 buses by 2032.

Santhosh notes that the population projection of 2032  and the expansion of the Chennai Metropolitan Area should also be factored in to meet the MoHUA benchmark. “More than the fuel system, increasing the number of MTC buses is the need of the hour for Chennai. Low-floor buses can be considered as it will be comfortable for senior citizens and children,” he adds.

Speaking on having environmentally-friendly buses, Dr Alby says that since most of these projects are multilaterally funded, there is a growing importance for climate-friendly buses/public transport options. “While 1,100 e-buses will be added to augment the fleet, we plan to procure 320 e-buses and 720 BS6 diesel buses to replace our old buses. This will give us around 2,140 environmentally friendly buses,” he notes.

MTC has also piloted two buses with CNG fuel and found them economical and environmentally friendly. “This will also be considered an option in future,” notes Dr Alby. 

Dealing with staff shortages

In response to staff shortages, he says that new 1,100 buses are to be contracted on Gross Cost Contract. “This means we are not buying the buses, we are contracting the buses. The bidder, who is awarded the contract, will own and operate the buses. They will bring the driver and look after the maintenance of the bus as well. We will pay a per/km fee to them. We use our own conductors and ticketing system. This will sort out the maintenance issue for the new buses,” he notes.

He notes that the recruitment process for 400 technical staff for the maintenance of old buses is underway. MTC has also outsourced some of the services to fill the vacancies.

As the city grapples with rising pollution and traffic congestion, the need for a more reliable and sustainable public transport system has never been clearer. With a combination of new buses, better maintenance, and a holistic approach to mobility, Chennai can hope for a cleaner, greener future.

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