New Delhi has kicked off a drastic new plan aimed at reducing its record-high air pollution by limiting the numbers of cars on the streets for two weeks.
Starting from January 1, the Indian capital will test a plan where private cars will be allowed on the roads only on alternate days, depending on whether their license plates end in an even or an odd number.
Most cars appeared to be following the rules on Friday and traffic was a trickle compared to the usual rush-hour chaos. But with schools and colleges shut, and many offices closed for the New Year's holiday, far fewer people needed to be on the roads.
"The reports we are receiving are that, by and large, Delhi has accepted the new rule. Till now, there have been few violations," Arvind Kejriwal, Delhi chief minister, told reporters.
Police appeared to be purposefully keeping a low profile - except for a handful of major intersections, where police and civil defence volunteers set up checkpoints to watch for wrong-numbered license plates, there was little official presence on the roads at all.
When cars were pulled over, the result was almost always a warning, not the $30 fine that has been announced.
"Today we are just educating drivers," assistant sub-inspector Krishan Singh told the driver of an Associated Press vehicle - with the wrong license plate number - when it was pulled over.
Last week, the city government announced a number of exemptions to the new rules, including top politicians, judges, police and prison officials, women and sick people and two-wheelers like motorbikes and scooters.
Still, the 15-day trial represents the most dramatic effort the city has undertaken to combat pollution since a court order in 1998 mandated that all public transport run on compressed natural gas.
'Most polluted city'
The World Health Organization last year named New Delhi the world's most polluted city. The pollution is at its worst in the winter, with grey skies and a dense cover of smog through the early morning hours.
Delhi has an estimated 7.5m registered vehicles and a large number run on highly polluting diesel. In addition to the massive numbers of vehicles on its roads, construction dust, the burning of crop waste in nearby farming areas and the city’s proximity to the Thar desert also add to the pollution.

Environmental expert Anumita Raichaudury said that it was good news for the city to finally have an emergency plan for times when pollution hits hazardous levels.
"It's important to clamp down by taking at least 50 percent of the vehicles off the roads for an immediate impact," Raichaudury said.