Can turning off the ignition at traffic signals help curtail pollution?

Doing your bit for the environment?
Doing your bit for the environment?
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On the afternoon of Nov. 4, as the national capital was engulfed in a toxic haze, 20-year-old student Sajid Hussain stood at the traffic signal in front of India Gate with a placard in his hand.

“Red light on, gaadi off,” declared the placard, which Hussain held up as soon as the traffic lights turned red. Twenty seconds later, the lights changed. The cars drove ahead.

Hussain has been recruited as a civil defence volunteer for the Delhi government’s anti-pollution campaign called “Yuddh, pradushan ke virrudh”, literally the war against pollution.

As a footsoldier in the war, he earns Rs623 ($8.43) a day. This comes at a cost: exposure to vehicular emissions and ambient pollution has left him gasping for breath.

“I have developed some breathing problems,” he said. But what bothered him more was that most drivers did not switch off their cars at the signal. “The signal is just 20 seconds…by the time we go to tell them the light turns green,” he said.

The campaign to switch off vehicles at 100 traffic signals situated in the busiest parts of Delhi started on a pilot basis on Oct. 21. It will continue till Nov. 15 after which it will end. At least 2,500 civil defence volunteers have been roped in across different traffic signals to instruct drivers.

What prompted the Aam Aadmi Party government in Delhi to come up with this campaign? What is the evidence it has relied upon? Did it actually need to deploy civil defence volunteers at traffic signals—and put them to risk—to communicate a message that could have simply been advertised on billboards?

Failed experiments

Every winter, the air quality in Delhi turns hazardous as lower temperatures and decreasing wind speed trap particulate matter closer to the ground.

The rise in pollution is often attributed to stubble burning by farmers in the neighbouring states of Punjab and Haryana. But studies have shown that vehicular and industrial emissions are also major sources of PM 2.5 and PM 10—tiny particles that can penetrate deep into the lungs and bloodstream and cause respiratory and other diseases.

Emissions from vehicles, in fact, contribute significantly to the poor air quality all year round, a study by the Indian Institute of Technology in Kanpur found in 2016. In the winter, vehicular emissions contribute 20% to 25% to the ambient air quality, and this number reduces to 6% to 9% in the summer, according to the study.

To battle vehicular pollution, Delhi had made a shift to cleaner fuels in the early 2000s. Commercial taxis were retrofitted to operate on compressed natural gas. In 2018, Delhi transitioned petrol and diesel-run vehicles to fuels that met higher emission standards Bharat Stage VI. Despite this transition, many vehicles that ply on the roads are still poorly maintained and continue to run on older fuels, and their density has only increased in Delhi.

In 2016, the Delhi government first attempted to control vehicular pollution in the winter by introducing an odd-even scheme. The scheme that was implemented in 2019 as well, allows vehicles with odd-numbered licence plates on the road on dates with odd numbers and those with even-numbered plates on others. However, questions were raised about the effectiveness of the policy.

This year, it has settled for something less ambitious—asking drivers to turn off the ignition at traffic signals.

How it works

In press notes, the Delhi government claims this could control nearly 15% to 20% of vehicular pollution. Reena Gupta, advisor to the capital’s environment minister Gopal Rai, admitted this was just a rough estimate, but added that the government had looked at several studies before formulating the campaign.

Some of the studies that Gupta pointed to look into the fuels used up and emissions released when vehicles remain idle. A vehicle is idle when it is parked or in the middle of traffic congestion.

A research paper published in the Journal of Cleaner Production in 2018 states that the idling fuel losses and corresponding emissions from vehicles at signal points were increasing with an escalating number of vehicles on the roads in Delhi. The researchers found that everyday around 9,036 litres of petrol, diesel, and LPG, and 5,461 kgs of CNG were lost because of the idling of vehicles at certain intersections in Delhi. This would amount to losses of nearly Rs33.4 crore, the study estimated.

The study also claimed that if 10% to 75% car drivers switched off the ignition then the total fuel idling consumption would be reduced by 8% to 70%. This would correspond with lowering emissions, it stated.

“Keeping the economic constraints aside, the major reasons for low acceptance of stop-start technology in developing country like India could be lack of awareness and advantages of fuel economy and emissions among general public, increase in cost of automobile, concerns related to additional wear/replacement and reduced life expectancy of vehicle and anxiety related to restarting of vehicle,” it said.

Gupta said the government felt it was important to bring about a behavioural change in citizens. “The idea is not to force anyone to change right now but to educate them and hopefully once they become aware, they will take that action,” Gupta said. “The volunteers are not forcing anyone and there are no penalties either.”

But what about the health of the volunteers who were being exposed to toxic air?

On the road

At India Gate, Hussain and the other volunteers have been standing at the signal daily since the campaign started from 6am till 2pm. What irks them the most is that the traffic signal turned red for merely 20 seconds.

Experts said the minimum time period for drivers to switch off their ignition should be a minute. “Broadly, if you are breaking for less than a minute then you probably do not switch off,” said Amit Bhatt of the World Resources Institute.

Bhatt said that some of the intersections that saw a bulk of the traffic in Delhi had signals timed for over a minute or even more than two minutes.

Other experts concurred. “It makes no sense when the signal is just 20 seconds,” said Anumita Roy Chaudhary of Centre for Science and Environment. “People should be able to predict the time of the signal. And there is data to show that this is good for fuel conservation.”

Gupta admitted this was a problem that had to be ironed out. “We found that some of these red lights do not have timers,” she said. “So the next step is to do a deeper analysis into the movement and timing of the red lights and synchronisation of movement.”

Apart from the timing of the signal, there were other reasons why drivers remain uncomfortable switching off the ignition, Bhatt said. Drivers of poorly maintained vehicles are more likely to be uncertain of whether or not the vehicles will restart on time.

“It is mostly autos and taxis because the vehicles are so poorly maintained that the driver also fears that if they switch off then it may not restart,” he said.

Going beyond

Experts were sceptical of the Delhi government’s claims that the campaign would substantially reduce air pollution in Delhi. “But we need to understand that at the traffic intersections, we have a more toxic ambient air quality and that is where it will make an impact,” said Bhatt.

Chaudhary said isolated measures would not work. The city needs to improve public transport to reduce the density of vehicles on the roads. “There is no quick response answer to this except that if we go back to our experience of the lockdown where we practiced work-from-home and if that can be institutionalised during winter so that the volume of traffic can be controlled,” she said. “That is one possibility as an emergency measure.”

Gupta said there were several challenges in the way of the Delhi government in expanding its public transport infrastructure. “The public transport needs to be augmented, but that is a complicated issue,” she said. “We are ordering buses, but there is no space to park them, because land is under DDA [Delhi Development Authority which comes under the Central government].”

But the bigger challenge, said Bhatt, was restricting private automobiles from plying on the road. “That will be a tough one to crack,” he said.

This article first appeared on Scroll.in. We welcome your comments at ideas.india@qz.com.