Of 86 lakh vehicles registered in Delhi, 29 lakh (9 lakh four-wheelers and 20 lakh two-wheelers) were registered 15 years ago.

Officials, however, are unsure as to how many of these vehicles are still in use. “This is accumulative data. We don’t know how many of these vehicles have been sold in smaller cities and towns or scrapped altogether,” a top government official said.

Delhi has added 1.35 lakh new vehicles to its roads since the tribunal’s order. About three-quarters of the city’s air pollution is reportedly caused by vehicular emissions.

A rise in the concentration of fine particulates, especially those of 2.5 microns — fine enough to get lodged deep in the lungs and blood tissues — has triggered respiratory and cardiac problems in the city.

Lawyer Vardhaman Kaushik, on whose petition the NGT gave its order on November 26, said, “Government departments claim to have stopped renewing registration certificates of vehicles older than 15 years, but they have admitted before the NGT that there is no concrete action against those plying on the road.”

Transport department officials claimed to have taken action against “eight to nine vehicles”. “We also put out a public notice, and requested the police to act,” said an official.

Senior traffic police official Muktesh Chander referred to the seizure of “many” polluting vehicles, but could not give a number.

According to automobile expert Tutu Dhawan, the NGT order is too tough to be implemented effectively. “The government record is not updated. Every four to five years people change cars. Vehicles end up in smaller cities and towns. You can neither quantify nor identify vehicles older than 15 years,” he said, adding that old polluting vehicles can still sneak in from satellite towns such as Gurgaon and Noida. “A vehicle’s age can indicate but cannot decide if it is polluting. A two-year-old car can be polluting. A 20-year-old one can be efficient,” he said.

The Centre for Science and Environment (CSE), an advocacy group, feels annual registration will help track vehicles and create a database. “A vehicle’s insurance benefits must be linked to its capacity to check pollution. A notice will come to the defaulting vehicle’s owner automatically,” CSE director general Sunita Narain said.

The Supreme Court, in 1998, had restricted plying of commercial vehicles older than 15 years. This was followed by several other orders, including those for cleaner fuels in subsequent years, but Delhi’s air quality has gone from bad to worse.

“We must check growth of cars with parking restraints and taxes. We should also ensure a good inspection programme and effective checks for smoky vehicles. Delhi needs to scale up walking, cycling and public transport, and leapfrog to clean emission standards,” said Narain.