Saying that Delhi’s public transport is insufficient to cater to the public and that the people are inconvenienced, the Delhi high court today asked the state government why it was necessary to run the odd-even traffic rule for more than a week.

"What is the need to run odd-even scheme after a week?" the court asked. "You will have to admit that you don't have enough public transport to ferry the public."

A report submitted by the government on the scheme so far was described as "vague" by the court today, which heard a series of petitions related to the traffic rules, including some that seek exemption for lawyers and senior citizens.

The court has asked the government to file an account by Friday on how pollution has been impacted by the new traffic rules, which were introduced on January 1 for a two-week period to cut smog in the world's most polluted capital.

Cars with odd-numbered licence plates are allowed on the roads on odd-numbered dates, and those with even-numbered plates on the other days.

Yesterday, the Delhi government claimed the new traffic restrictions are registering an improvement in the city's air, stating a "definitive declining trend" in the levels of Particulate Matter (PM 2.5), the tiniest and deadliest of all the microscopic particles.

"According to the scientists of the Delhi Pollution Control Committee (DPCC), 80 per cent of PM2.5 air pollution is caused by vehicular traffic and reduction in its levels, even in outer areas of Delhi shows that reduction of four wheeled vehicles on roads since the New Year Day is having a positive impact," the government said in a statement.

Pollutant levels in Delhi regularly hit 10 times the World Health Organization's safe limits. Experts have warned against expecting any dramatic reduction in the amount of respirable particulate matters, PM 2.5 and PM 10, which depend on a host of atmospheric parameters.