A green body has cautioned against the Delhi government's 'odd-even' scheme becoming a regular affair, and suggested other options to control pollution levels in the national capital region."The study of the two phases of odd-even scheme in Delhi suggest that it is useful only when high pollution episodes are expected. We do not see merit in regularising the scheme," said Ajay Mathur, TERI Director General.An impact assessment study released by The Energy and Resources Institute (TERI) on Monday claimed that the impact of odd-even scheme declined during the second phase in comparison to the first phase in winter. "The impact of the odd-even scheme with respect to traffic counts, average speeds and air quality declined during the second phase...This decline could be probably due to people opting for second cars with alternative number plates, installations of CNG kits or enhanced use of taxis," the study claimed. The green body also claimed that regularization of 'odd-even' could reduce the impact of the scheme. "As in the case of other cities in the world that have tried out the odd-even scheme in the past, people could look for alternatives by purchasing new/old cars or motor bikes, which would, over a period of time, neutralize and negate the positive impacts," TERI study claimed. The assessment report claimed that the odd-even scheme yielded in reduction of Particulate pollution by 4-7 percent only during both the phases.
"During second phase, the general variation of PM 2.5 concentration due to daily changes in local emissions, meteorology and influences from outside Delhi was 42 percent. The reduction achieved from odd-even scheme during this phase seems too small (4 percent) to be captured, among the other more dominating factors," TERI said.TERI also suggested alternative ways to control pollution, including through congestion pricing and by strengthening the public transport infrastructure. Congestion pricing aims to reduce the number of vehicles on the road, by charging based on the number of people using a vehicle or by charging vehicles on entry in restricted zones or at certain times. It was successful in cities such as Singapore, London, Sweden, Rome, Durham, Seoul, San Diego, and other cities. "We need multi-sectoral measures for the whole NCR to effectively reduce air pollutant levels, which calls for regular air quality management plans based on scientific studies," Sumit Sharma of TERI said.TERI had earlier also stated that the number of exemptions given by the Delhi government are a hurdle to the odd-even scheme."Instead of giving exemptions, why not charge a woman for the exemption that she enjoys during odd-even, and use that money to promote public transport," an environment expert said.