Odd-even scheme in Delhi: What studies say and other cities that have implemented it

Residents of Delhi NCR have been gasping under the hazardous smog that has engulfed the capital this winter. Despite showing marginal improvement, air quality still remains in the ‘poor’ category in most parts of Delhi-NCR.

As a mitigating measure, Chief Minister Arvind Kejriwal has brought back the odd-even rule which he had initiated in 2016. The scheme, which is in force from November 4-15, will be implemented from 8 AM to 8 PM from Monday to Saturday and people violating the rule will face a penalty of Rs 4,000. The scheme is also applicable to hybrid and CNG vehicles, unlike the last time. Twenty-nine categories of cars, which include emergency and enforcement vehicles, those of the President and Prime Minister and cars with women drivers, provided that it has only women and children under 12 as passengers, will be exempt from the scheme.

The Delhi Police have issued 406 challans in the first three days of the rule and Delhi Deputy Chief Minister Manish Sisodia has said that people have been ‘religiously’ following it.

Odd-even not enough

A flagship scheme of the Aam Aadmi led Delhi government, the odd-even policy was first introduced from January 1-15, 2016, with the hope of reducing pollution by rationing out cars that ply on the road. The scheme, though a positive step, may not be enough, believe experts.

As per a study conducted by the Centre for Environmental Science & Engineering at the Indian Institute of Technology (IIT) Kanpur, published in the Environmental Science and Policy, the vehicle rationing which had been in place in 2016, may have shown only a slight reduction in the levels of PM 2.5. The study cited published reports which said that after the odd-even traffic restriction, there was only an improvement of about 9 per cent in the average vehicle speed between 11 AM and 5 PM in Delhi. Further, the policy was also able to reduce the number of private cars on the road by only 35 per cent, as opposed to the expected 50 per cent.

As per data published by the Delhi Pollution Control Committee, the primary contributors to PM 2.5 in winter in Delhi are secondary particulate particles (around 25–30 percent), vehicular emissions (around 23–28 percent), biomass burning (around 17–26 percent), municipal solid waste burning (around 9 percent), and suspended soil and road dust. This points to the fact that restricting vehicular traffic alone is not the only solution to countering PM 2.5. Hence, as per the IIT Kanpur study, where the odd-even rule would have worked, is in the reduction of exhaust emissions with reduced cars and a marginal reduction in road dust and secondary particles.

An assessment conducted by the Central Pollution Control Board, Delhi, in 2016, showed that while some reduction in air pollution could be possible by following the scheme, it alone does not work, significantly. Another study conducted by the Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research, Mohali, went a step further in stating that the traffic rule implemented in Delhi during 1-15 January 2016, did not result in any significant reduction in PM 2.5 levels, as many four-wheeler commuters chose to beat the 8 am – 8 pm restriction by travelling either earlier or later on.

In Delhi, PM 2.5 levels are at an average three times higher than the permissible limit declared by the World Health Organisation (WHO), which is 60 micrograms per cubic metre. Anything upwards of 100 micrograms, makes the air dangerous to breathe in. Particle matters less than 2.5 microns in diameter, or PM2.5, which are found in soot, smoke and dust, get lodged in the lungs, causing long-term health problems such as cancer, chronic obstructive pulmonary diseases and stroke.

Vehicular traffic in Delhi has increased exponentially, and, as per data from the Government, on an average, from 2011 onwards, about 1,50,000 cars/jeeps and 3,00,000 two-wheelers have been registered every year. While initiatives have been undertaken, such as bringing in compressed natural gas to replace petrol/diesel, the metro and flyovers, pollution levels have increased exponentially with the increase in vehicular traffic.

How other cities have adopted

A number of cities around the world have experimented with the odd-even scheme, with varying results. In Mexico City, which has improved since it was named the most polluted city in the world in 1992 by the UN, the Government introduced the Hoy No Curcula or no drive days way back in 1989. The program consisted of curbing the movement of vehicles from Monday to Friday, based on the last four digits of the license plate number. In 2008, the programme was expanded to include Saturdays as well. However, as per a study, the vehicle ban did not help much in reducing pollution, as citizens often managed to get around the restrictions by buying an extra vehicle, using taxis or carpooling.

To tackle growing air pollution, Paris opted to apply the odd-even rule on a Monday in March 2014. While cars with even number plates were barred from the city 5.30 AM till midnight, public transport was made free for the day. A Eur 22 fine was imposed on those who flouted the rule. This resulted in a reduction in traffic by 18 per cent in a single day, while pollution during rush hour reduced by 20 per cent. Further, rush-hour levels of nitrogen oxide fell as much as 30 per cent. Paris, again, implemented the scheme in December 2016, with a fine of Eur 22 for violators.

Beijing has also been following rationing of vehicular traffic, with the rules depending on the pollution levels. In 2008, during the Beijing Olympics, Beijing followed the odd-even rationing rule to improve air quality during the Games. Post the implementation, a 40 per cent reduction in vehicular emissions was reported. What helped make the scheme a success was that in Beijing there were no VIP exemptions, unlike in Delhi. Also, while vehicular purchases reportedly went up during the restrictions in Delhi, Beijing’s lottery system for the purchase of new vehicles, which has been in place since 2011, makes buying cars a matter of luck. In Beijing, the annual quota of cars which was 2,40,000 in 2013, as per Bloomberg report, fell to 1,00,000 in 2018.

As the studies indicate, while vehicular rationing may be a positive step towards reducing the ghastly levels of pollution that Delhi faces, unless strict measures are not put in place in terms of curtailing the number of vehicles each household can buy, increasing the fines and ensuring that people are not exempted from the rule, the scheme will have little effect.