In a change from its earlier plan, the Delhi government on Tuesday said private vehicles with odd and even registration numbers will ply on odd and even dates respectively from January 1.
"It will be date-wise," Transport Minister Gopal Rai said, days after the government said odd numbered vehicles would ply on Mondays, Wednesdays and Fridays and those with even numbers on Tuesdays, Thursdays and Saturdays.
Rai clarified that odd numbered vehicles would be allowed on the roads on odd dates "like 1, 3, 5 and so on" and even numbered vehicles on even dates "like 2, 4, 6 and so on".
The rationing of the huge bulk of vehicles on Delhi's roads, aimed at curbing alarming levels of air pollution, would not apply on Sundays when all vehicles can ply, the minister said.
The restrictions will apply from 8 a.m. to 8 p.m. The formula would be experimented from January 1 to 15 to see if it succeeds.
There has also been no decision yet on the hundreds of thousands of two-wheelers which environmentalists say also contribute to pollution and need to be curbed.
The complete blueprint for the ambitious odd-even formula - including categories that would be exempt - would be ready by December 25, Rao said.
The Delhi government said it had held detailed discussions with Delhi Traffic Police and Delhi Metro in a bid to coordinate what is expected to be a mammoth exercise.
Chief Minister Arvind Kejriwal will hold a further review meeting of all departments on December 10.
The Delhi announced the odd-even formula in response to judicial warnings of rising air pollution, and after the Delhi High Court said that the national capital was becoming a "gas chamber".
The plan has been widely welcomed by environmentalists, and also Chief Justice of India T.S. Thakur. Criticism from opposition parties has since abated.
Minister Rai said 1,000 low-floor buses would be bought immediately in a bid to meet the need for more public transport when the number of vehicles fall steeply on the roads from January 1.
Delhi has nearly 90 lakh registered vehicles, almost a third of them cars. Some 1,500 new vehicles are added every day.
