Delhi government on Monday announced that the odd-even car rationing scheme will be enforced in the city post Diwali, from November 13 to 20, to control air pollution.

Environment Minister Gopal Rai said that a decision on extension of the odd-even scheme will be taken after November 20.

First implemented in 2016 by the Aam Aadmi Party (AAP) in Delhi, this will be the fourth time the odd-even car rationing scheme will be enforced in the city in view of the rising pollution levels, even as studies and experts have mixed views on its efficacy.

The odd-even scheme permits cars to operate on alternate days based on their odd or even number plates. The scheme was first implemented in 2016 by the Arvind Kejriwal government in January and then in April the same year. Emergency and police vehicles, two-wheelers, women-driven cars were exempted under the scheme.

In 2019, when the scheme was implemented in November, two-wheelers and electric vehicles were exempted along with medical emergency vehicles and those carrying school children in uniform. Vehicles carrying VIPs, only women and those occupied by differently-disabled persons were also exempted.

However, studies conducted on the efficacy of the scheme have also said that it did not have the desired impact on the pollution levels.

The Energy Policy Institute at the University of Chicago and Evidence for Policy Design had analysed the impact of the odd-even scheme implemented in 2016. It was found that Delhi witnessed 14-16 per cent reduction in PM2.5 levels during the hours the scheme remained in force in January that year. However, there was no reduction in pollution when the scheme was brought back in April that year.

A study by IIT-Delhi researchers had also found that the rationing of vehicles on Delhi’s roads reduced air pollution by only two to three per cent when the scheme was introduced for the first time in January 2016.

On Sunday, the Centre had also taken a call to invoke all actions as envisaged under Stage-IV of Graded Response Action Plan (GRAP) – ‘Severe+’ Air Quality (Delhi’s AQI > 450), with immediate effect in the entire national capital region (NCR).

The steps include government taking appropriate decision on permitting work from home for employees in Central government offices. State governments may also consider additional emergency measures like closure of colleges/ educational institutions and closure of non-emergency commercial activities, permitting running of vehicles on odd-even basis of registration number, it said.