"Vehicles registered after 2005 and 2006 were BS-III and BS-IV fuel-compliant. We are estimating that almost all the decade-old polluting vehicles will be off the roads. However, at the national level, we will come out with a policy to phase out trucks and other heavy vehicles, which are over 12 years old," an official said.

Sources said since now there is a consensus that only BS-IV fuel-compliant trucks should be allowed to enter the National Capital Region and particularly Delhi, oil companies need to expedite their plans to make fuel available at all stations on the national highways.

"Since states are still registering BS-III trucks and issuing national permits, there are chances of such trucks entering Delhi. But once you have the BS-IV fuel on national highways, we can direct states to issue national permits only to the trucks that run on cleaner fuel," a transport ministry official said.

On December 2, TOI had first reported the ministry's move to notify 'end-of-life' scheme for heavy commercial vehicles to phase out two-axle mini-trucks after 12 years, multi-axle vehicles after 15 years and trailers after 25 years.

Meanwhile, to deal with the issue of polluting interstate goods vehicles entering the big cities that are struggling to get clear air, the road transport ministry has provisioned developing logistic hubs along the national highways and bypasses.