Vehicles with licence plates ending in odd numbers will be allowed to ply one day, followed by those with even numbers the following day, the Delhi government said on Friday.

It’s the most drastic measure taken by any government in India to curb pollution choking the country’s cities. The decision has been timed to take effect in winter, when pollution worsens.

Delhi’s air has been ranked the world’s dirtiest by the World Health Organization.

The Delhi government will also shut down a unit of the coal-fired Badarpur power station in the city-state.

The move will affect an estimated 8.4 million vehicles—2.8 million cars and 5.6 million motorcycles and scooters—registered in Delhi.

Many thousand more vehicles registered in towns outside the capital, such as Gurgaon (Haryana) and Noida (Uttar Pradesh), that commute daily to the city will also go off the roads every alternate day.

“As far as Delhi’s air pollution is concerned, we recognize that the situation is serious. But as we all know, air pollution is a global problem in many cities the world over, and in Delhi, air quality is going from bad to worse for the last 10 years,” environment minister Prakash Javadekar told PTI.

“With people’s participation, we can win the war against pollution... Because I believe fresh air is the birthright of every citizen, and they must get it and we are duty-bound to do that in a time-bound manner,” he added.

Reached by Mint, Javadekar refused to comment on the Delhi government’s decision.

Separately, transport minister Nitin Gadkari said the government will soon come out with an integrated policy to scrap commercial vehicles that are over 10 years old to check rising pollution.

“The cost of vehicle will be valued at 10-15% of original cost. If vehicle cost is Rs.10 lakh, scrap will be 10% of it,” Gadkari told reporters, according to PTI.

The Aam Aadmi Party-government said it would strengthen the public transport system, including the Delhi Transport Corporation that runs buses, and the Metro rail network.

Delhi’s chief secretary K.K. Sharma said the details of implementation of the plan will be worked out in the coming days by the traffic police, transport department, municipal corporations and other stakeholders.

The Delhi government will consider hiring school buses that operate for a limited period and other vehicles to augment transport.

The flip side of the move is that people who can afford it may buy a second car.

“I don’t know if people will buy a new car immediately as they won’t know if the policy will last,” said an automobile industry executive on condition of anonymity. “It will give a push to public infrastructure. It will increase the concept of car sharing.”

The decision was taken at an emergency meeting presided over by Delhi chief minister Arvind Kejriwal, a day after the Delhi high court criticized the living conditions in the capital, comparing it to “a gas chamber”.

A bench of justices Badar Durrez Ahmed and Sanjeev Sachdeva said the two major causes of air pollution in Delhi were dust particles and vehicular emissions. The bench directed the centre and the state government to ensure no construction of buildings or roads takes place without first ensuring that generation of dust particles is minimized.

The Delhi government is also considering allowing trucks into the city only after 11pm.

Following a court order, the Delhi government recently imposed an environmental levy on trucks entering the capital en route to other cities.

Several Chinese cities have slapped limits on cars, based on licence plates, to tackle congestion and pollution, but it is the first time that an Indian city is seeking to implement such a measure.

Delhi’s air routinely worsens in the winter, as residents start lighting fires to stay warm, and as cooler air and clouds trap pollutants.

But unlike Beijing, which also suffers from hazardous haze levels, Delhi does not issue public health warnings.

Environmentalists praised the move and said people who have been complaining about severe pollution in the capital should support the decision, which they said was long overdue.

“As far as air pollution in Delhi is concerned, desperate times require desperate measures. This was long-pending. A lot of other steps will be needed along with this. But what this will be doing is reduce the load of vehicles on Delhi. All agencies will need to work together to implement it,” said Anumita Roychowdhury, executive director at the Centre for Science and Environment, a non-governmental organization.