At the ITO crossing in central Delhi, traffic moves slowly but without the usual pile-up during peak-hour evening traffic. Young men wearing neon vests and face masks stand at the city's most congested points. Some hold placards that read "Pollution-free Delhi".'
Police monitor the licence plates of cars passing through the crossing. They flag down a violator and issue him a 2,000-rupee (S$43) penalty for driving a car with an odd- numbered plate on a day when only even-numbered plates are allowed. He protests but pays up on the spot.
Since Jan 1, and until Jan 15, only odd-numbered-plate cars are allowed on Delhi's streets on odd dates and even-numbered plates on even dates daily, except Sundays. Women and motorcycles are exempt from the restrictions aimed at bringing down pollution levels, which have doubled in a decade.
The trial run is going strong. Streets are visibly free of congestion. But environmentalists say PM2.5 levels of particulate matter - the most hazardous of small airborne particles - have continued to remain in the severe range above 250 micrograms per cubic metre.
WEAK TRANSPORT INFRASTRUCTURE
It has become very difficult to go out. There is no last-mile connectivity with public transport. I took an auto rickshaw (three-wheeler) and he (the driver) asked for 100 rupees for a 2km stretch. It would otherwise have cost less than 50 rupees.
MR SRINIVAS PANDA, a bank official, who works in Central Delhi
WORTH THE SACRIFICE
It's a kind of a sacrifice that all of us have to do. So there is no reason for us to crib about it. If we do it we gain.
MR NAVEEN JONEJA, 64, a retired graphic designer, on staggering the use of cars on the city's roads
This, they said, was mainly due to high moisture levels and low winds, which have made this winter more polluted than last year.
"There are reduced wind speeds, so there is lower dispersal of pollutants," said Mr Sumit Sharma at the Energy and Resources Institute in Delhi. "The effect of the odd-even scheme is getting lost. "
Ms Anumita Roychowdhury, executive director of the Centre for Science and Environment, said: "The dip in pollution during the morning and afternoon has been sharper and quicker during the odd-and-even trial and this validates the points that emergency action is required. But air quality remains in the severe category."
However, the Delhi government has claimed that pollution levels are down by 33 per cent since the trial began.
Delhi sees 1,400 vehicles added every year. Apart from vehicular pollution, industries just outside the city, construction in satellite towns and burning of residue in farmlands in neighbouring Haryana and Punjab states have all added to the city's pollution problem.
On Wednesday, the Delhi High Court asked the city government to prove that the odd-even formula was cutting down pollution and asked why it had to last for more than a week. The court, noting that restrictions have inconvenienced commuters, has asked for pollution data for the first week of the year.
Though 3,000 more buses have been deployed and the metro is running at full capacity, people complain that the weak public transport infrastructure is a problem.
"It has become very difficult to go out. There is no last-mile connectivity with public transport," said Mr Srinivas Panda, a bank official, who works in Central Delhi. "I took an auto rickshaw (three-wheeler) and he (the driver) asked for 100 rupees for a 2km stretch. It would otherwise have cost less than 50 rupees."
Mr Naveen Joneja, 64, a retired graphic designer, however, said that to curb pollution, residents had to make sacrifices. "It's a kind of a sacrifice that all of us have to do. So there is no reason for us to crib about it. If we do it, we gain."
Many others too had no problem with the restrictions. Chief Justice T.S. Thakur has been carpooling, while ministers in the Delhi government have been taking the metro, bus and even cycling to work.
Tax consultant Rakesh Sharma said he had no problems taking the metro from his house in East Delhi to his office in Connaught Place in Central Delhi. "I have actually been saving time on the metro," he said.
Still, experts say the biggest gain from the odd-even restriction is that it has called attention to the severe pollution in the city. "Everyone is discussing pollution. People want clean air and know that pollution is bad for their children," said Mr Vikrant Tongad of the Social Action for Forest and Environment. "The main benefit (of odd-even) is increased awareness."