The Energy and Resources Institute (TERI) in its analysis of the scheme said that although the percentage effect could be small, but given the concentrations as high as in Delhi, the absolute reductions in PM 2.5 concentrations are “significant” as it can help reduce health impacts.

TERI said that the scheme has brought “considerable” additional benefits including reducing on road congestion, increase of average car speeds, reduced fuel usage and made significant impact on public awareness levels on air pollution and its impacts on human health.

TERI said that the scheme can be strengthened by improvement in public transport systems which will help in removing the exemptions applied during this phase. TERI analysed the ambient air pollutant concentrations in Delhi from December 24 to January 15 at four stations – Mandir Marg, Punjabi Bagh, AnandVihar and R K Puram. “In comparison to the period between December 24-31, 2015, air pollutant concentrations increased significantly in the first week of January. However, a decline was observed in the concentrations during the second week. These changes in concentrations are apparently mainly due to meteorological influences. “Based on the contribution of private cars reported in previous studies, a marginal impact on air pollutant concentrations could be ascertained, which means that pollutant concentrations could have been marginally higher if the odd-even scheme had not been in place. “The percentage effect of odd-even scheme could be small, but when the concentrations are as high as in Delhi, the absolute reductions in PM 2.5 concentrations are significant which can help reducing the health impacts,” it said. The NGO said that most importantly, the levels of cooperation with program by the citizens were extremely high with very few reported violations which argues well for extending and enhancing the measure. It said that the scheme in a short space of 15 days prompted the IT-based applications and other means of car pooling as well as induced ‘work from home’ policies in several offices. TERI also carried out traffic counts on Vikas Marg near Lakshmi Nagar metro station on December 21, December 23, January 4 and January 11 in which a reduction of 21 per cent was observed in number of cars on road. “In conclusion, the odd-even scheme is found to be beneficial and it can be used as a measure for reducing congestion and pollution more specifically during the days of high pollution episodes to cut down on the peak levels of air pollutants,” TERI said. “The scheme can be strengthened by improvement in public transport systems which will help in removing the exemptions applied during this phase,” TERI said. Suggesting measures, TERI said that the odd-even scheme could also be enhanced in a number of ways. “For example, on a main arterial road, at least during peak commuting hours, cars may be required to have atleast 3 to 4 passengers and all two wheelers to have a pillion rider. “Exemptions from such requirements would be obtained by prior payment of a significant congestion charge. Policy and regulatory issues related to the provision of car pooling IT services, whether on commercial or non commercial (cost sharing) basis, should be resolved,” it said. Noting that while odd-even scheme can provide some air quality benefits and cannot be relied upon for achieving air quality standards, TERI said that there are many other interventions that are needed to be taken in the vehicular sector and others for effective air quality control. “There are many other sources which impact the air quality in Delhi, significantly. Rather than just restricting the analysis to Delhi, it is time now to realise that there are many sources in the wider NCR region which contribute to deterioration of air quality in Delhi, further research and mitigation plans need to be developed for air quality control in NCR,” it said. Noting that heavy duty vehicles (trucks and interstate buses) have the highest share in vehicular emission inventories of Delhi, TERI said that trucks still remained on BS III standards. “The recent announcement of MoRTH to shift directly to BSVI vehicle emission standards (including trucks) is a very important step for long term reduction in vehicular emissions and improvement in air quality. However, timely and proper implementation of these standards needs to be ensured,” it said. TERI said that other than vehicles, there are many other sources in NCR which contribute significantly including usage of diesel generator (DG) sets, agricultural burning of residues and industries.