The Delhi government announced on Friday each private car and two-wheeler will be allowed on the city's roads only every alternate day from 1 January, in a bid to even the odds stacked against authorities in their efforts to clean up the capital's toxic air.
Private vehicles will be allowed to run on the streets on alternate days depending on whether their licence plates end in even or odd numbers, the government declared a day after it faced criticism from the Delhi High Court over the city's mounting pollution problem.
The method, more commonly known as road space rationing, is followed in various forms across the world, though experts said implementation could prove to be a major challenge, as well over two million vehicles would have to be kept off the roads every day.
In fact, the twitterati had a field day after the announcement, with jokes about how one could cheat the system and also how the city's VVIPs, not used to curbs, would get around the restrictions.
''We are talking about implementing this plan in a city where no one is ready to follow basic traffic rules,'' said a senior government official on condition of anonymity.
The model is already in force in Beijing, which Delhi surpassed last year to be ranked as the world's most polluted city in a World Health Organisation report.
The decision taken at a meeting headed by chief minister Arvind Kejriwal will not apply to CNG-driven buses, taxis, auto-rickshaws and emergency vehicles but will cover automobiles entering Delhi from other states.
Officials say even-numbered cars will be allowed to run on even dates and odd-numbered ones on odd dates.
A committee comprising members of the environment department, traffic police, transport department and the divisional commissioner will decide how the policy will be implemented. Till then, traffic police may get interim powers to penalise errant drivers under the new rule.
The sweeping move, like the one adopted by Beijing in 2008 ahead of the Olympics, will apply to a large bulk of nearly nine million vehicles registered in Delhi, which adds about 1,500 new vehicles to its roads every day.
The city's vehicular population, which causes choking jams on all weekdays, includes about 2.7 million cars.
The government also announced a slew of other measures that could help curb air pollution, including stopping roadside parking to battle congestion, improving the public transportation system and bringing cleaner fuel to the city.
The capital city also plans to shut down one of its oldest and least efficient thermal power plants. The Badarpur plant, commissioned in the early 1970s, uses outdated equipment and often breaks down.
Traffic police will also be told to ensure that diesel-guzzling trucks, which transit through the city at night, enter only after 11pm. Currently, trucks are allowed to enter the city at 9 pm, often resulting in massive traffic jams.
It was not immediately clear when the measures would take effect or exactly how long they would continue.
Earlier this year the city ordered all private cars older than 10 years to be taken off the roads, becoming the second major city in the world to do so after Beijing.
Last year, the World Health Organisation named the Indian capital as the world's most polluted, with 12 other Indian cities ranking among the worst 20.
In November and early December the city's air quality slumped to hazardous levels, with levels of PM2.5 pollutants, the very fine particles that get lodged inside the lungs and cause the most damage, soaring to 12 times above WHO's safety level of 25 micrograms per cubic meter.
The city has been blanketed in grey smog, and while there is no reliable data on respiratory diseases, most doctors in the capital report a sharp spike in pollution-related illness during the winter months.