The National Green Tribunal (NGT) on Friday questioned the proposed odd-even formula for vehicles to curb pollution in the national capital.

Such a move may not achieve the desired purpose as the tribunal said that the government's move will encourage people to buy two cars with even and odd number plates.

The NGT, meanwhile, ordered that no new diesel vehicles would be registered in Delhi.  The NGT also directed the centre and the Delhi government not to buy any diesel vehicles for their departments. Nearly 23 per cent of the cars registered in Delhi are diesel. Diesel cars can legally emit 7.5 times more particulate matter than the petrol versions and produce more toxic nitrogen dioxide.

The Delhi government has announced that from January 1, 2016, private vehicles with odd registration numbers will ply on Mondays, Wednesdays and Fridays, and with even numbers on Tuesdays, Thursdays and Saturdays.

Both odd and even number vehicles can ply on Sundays.

One of the main criticisms of the odd-even formula has been the lack of adequate number of public vehicles that can accommodate those who will not be able to use their vehicles in the first fortnight of January.

The government has asked Delhi Transport Corporation (DTC) to double the number of buses from January 1 to 15 next year when the odd even formula will be implemented on a trial basis.

Delhi Metro has also been asked to increase the frequency of trains during this phase to accommodate the extra commuters.

Transport minister Gopal Rai said 4,000 private contract CNG buses and 2,000 CNG school buses will be added to the existing fleet of 6,000 DTC and cluster buses.

Exempting two-wheelers from the odd-even formula for plying of vehicles in Delhi to combat pollution will defeat the purpose, sources said Wednesday,

Meanwhile, in a report by IIT Kanpur states two-wheelers are responsible for more pollutants than cars when it comes to air pollution. The report states, “46% pollution is created by trucks in the city when it comes to both PM (particulate matter) 10 and PM 2.5. Two-wheelers contribute to 33% of the pollution, 10% is contributed by four-wheelers. Buses contribute to 5% of the pollution, whereas 4% is done by light commercial vehicles, and the rest is the contribution of three-wheelers and other factors.”