Curtailed exemptions to vehicles from the scheme, more public transport options with better frequency and similar odd-even regulation for areas around Delhi were some of the suggestions given by experts to curb pollution in Delhi.

Four-wheelers with odd and even registration numbers plied on Delhi's roads on alternate dates during the fortnight on a pilot basis.

Vivek Chattopadhyay, deputy coordinator at Centre for Science and Environment's (CSE) air pollution monitoring unit, said the scheme had helped lower peak pollution levels during smog.

"As per our analysis, peak pollution levels during smog episodes dropped considerably. But during the dry run, there were too many exemptions on vehicles, which should be avoided to curb pollution better," Chattopadhyay told IANS.

He stressed the need for curtailing too many exemptions to the regulation and to check pollution by diesel vehicles and construction.

According to Vikrant Tongad, an environmentalist working with Delhi-based Social Action for Forest and Environment (SAFE), more steps apart from the odd-even scheme were needed for the pollution in Delhi to come down considerably.

"There is no drastic change in pollution levels, but Delhiites certainly got a respite from long snarls-up," Tongad told IANS, adding it would be difficult to determine exactly how much pollution lessened due to the scheme.

In winter, air contaminants get trapped close to the ground. So it will be difficult to determine how much reduction in pollution levels the scheme contributed to. However, Delhi Transport Minister Gopal Rai said on Friday a reduction in pollution by at least 20-25 percent was witnessed.

Tongad said without checking polluting construction methods, curbs on industries and two-wheelers, there won't be any considerable change in the Air Quality Index (AQI) in Delhi and surrounding places.

As of January 15, the AQI measured at 4 p.m. by the Central Pollution Control Board stood at a "poor" level, with an index value of 292, while the areas around Delhi like Faridabad and Agra stood at "very poor" levels. These touched "severe" levels in December.

It pointed to the need for odd-even scheme and stricter norms for areas around Delhi as well, the experts said, adding that a master plan should be in place to improve public transport system.

The Delhi Metro Rail Corporation handled at least 27 lakh passengers on an average each day, with many instances of over-crowding at Metro stations during peak hours.

"The crowd at Metro stations during peak hours was maddening on some days, after the scheme was introduced. We need more public transport options with better frequency," said South Delhi resident Pragnya Kumar.

Even though the authorities put in place increased frequency of Metros rakes and more public transport buses, these did not suffice.

A considerable number of people opted to share cabs, a good sign even after the end of the scheme, private taxi companies said.

"We witnessed a significant increase in demand - almost in double digits - over the last few days in Delhi National Capital Region. Since the launch of Uber's carpooling initiative, we have seen a steadfast rise in the number of people opting to carpool," said RuchicaTomar, spokesperson of Uber.

Tomar said the company was optimistic about the continuation of the carpool even after the end of the odd-even scheme, since it helped cut traffic congestion.