The Indian capital, Delhi, has launched a vehicle rating system as it tackles dangerous levels of pollution.
Private cars with odd and even numbers will be allowed on the roads only on alternate days from November 4 to November 1
The system was introduced in 2016 and 2017 as well, but it is unclear whether it actually helps reduce pollution.
Hazardous particulate matter levels in the air – known as PM2.5 – are much higher than recommended .
The deteriorating air quality has put millions of people at risk for respiratory diseases.
Health officials have asked people to stay indoors and refrain from any physical activity. The school is closed until Tuesday and the shutdown is likely to be extended until Friday as the city continues to suffocate under a dense smog blanket.
Delhi Chief Minister Arvind Careval said the car's rationing system, known as the "odd plan," would take hundreds of thousands of cars on the road.
Offenders will be fined 4,000 rupees (£ 44; $ 56), which has doubled compared to previous years.
Only emergency vehicles, taxis and two-wheelers will be authorized. Self-driving women will also be exempted from the rule.
Hundreds of teams of police, transportation and civilian volunteers were deployed to implement the rule. It is likely to cause further pressure on the public transport system.
But officials say they have been prepared as additional buses and subway trains will be deployed during this period.
But there are questions if the odd rule will drastically reduce pollution levels. Such measures in the past have drastically reduced traffic congestion in Delhi but have not had a significant impact on pollution levels.
Experts say vehicle emissions are just one of several factors that make the city a "gas chamber".  A major factor behind the high levels of pollution at this time of year are farmers in neighboring countries who are harvesting crops to clear their fields.
This creates a deadly powder cocktail, carbon dioxide, nitrogen dioxide and sulfur dioxide – all made worse by the fireworks that went off during the Hindu Diwali festival a week ago.
Car burns, construction and industrial emissions also contributed to the smog.
How Does The Odd Reading Plan Work?
This is the third edition of the Odd Even Reading Plan of the Delhi Government and it was introduced with a few tweaks. Here's what you need to know if you plan to get your car out of town:
Private cars with license plates ending in odd and even numbers will only be allowed on alternate days from 4 to 15 November. So if your number plate ends with one, three, five, seven and nine, you can only drive on odd dates (4,6,8,12 and 14) and if it finishes at zero, two, four, six and eight, you can drive on even dates (5,7,9,11,13 and 15).
The restrictions are from 8am to 8pm Monday through Saturday and will also apply to cars coming from out of town. Sunday is free for all.
Unlike earlier years, vehicles operating on clean fuel such as CNG (compressed natural gas) will not be allowed, although electric vehicles are still exempt.
The Chief Minister of Delhi and other ministers are not released, although there is a fairly long list of those who have been granted exemption from the rule:
- All VIPs, including the President, Vice President, Prime Minister, Government Ministers, several senior politicians, judges and foreign diplomats
- Women driving alone or with women passengers only. Children under 12 years of age are permitted
- Private vehicles with male drivers at school or on the way to a hospital for medical treatment if they can "prove emergency"
- All two-wheelers including motorcycles and scooters  Taxis and auto-rickshaws
- Emergency vehicles
- Disabled drivers