The Delhi government may implement the odd-even road rationing scheme again as air pollution rises, Transport Minister Kailash Gahlot said on Thursday, according to ANI. He said the government might have to resort to emergency measures to curb pollution.

The odd-even scheme prohibits vehicles from plying on roads based on the last digit of their registration numbers. Only vehicles with numbers ending with an odd digit can ply on odd dates while others are allowed only on even dates. However, all cars are allowed to ply on Sundays.

On Wednesday, Gahlot wrote to the Delhi Transport Corporation and senior officials of his ministry, asking them to be “fully geared up” for the odd-even scheme as and when it is announced, PTI reported.

In 2016, the city-state adopted the method twice to reduce the number of cars on the road – once from January 1 to 15, and again between April 1 and 15.

After Diwali was celebrated on October 19, the Delhi government suggested that the Centre could consider using helicopters to sprinkle water on roads to settle particulate matter. The government offered to pay for the aerial sprinkling of water.

In January, the Ministry of Environment notified a Graded Response Action Plan to fight air pollution in the National Capital Region. The plan allows for measures such as odd-even rules and restrictions on construction work to be implemented when level of PM2.5 breaches 300 micrograms per cubic metre and PM10 levels stay above 500 micrograms per cubic metre for two days in a row.