Doubts over efficacy of vehicle rationing persist
Studies by Indian researchers to ascertain the impact of the odd-even on pollution levels, when it was first introduced in January 2016, however, have shown mixed results.Updated: Sep 13, 2019 22:14 IST
Chief minister Arvind Kejriwal, while proposing to roll out the odd-even vehicle rationing scheme between November 4 and 15, said that such measures had helped bring down pollution level by 14%-16% in 2016.
He was referring to the findings of a joint study undertaken by the University of Chicago and Harvard University, which was presented to him on Thursday.
Studies by Indian researchers to ascertain the impact of the odd-even on pollution levels, when it was first introduced in January 2016, however, have shown mixed results. While some revealed that the scheme didn’t have the desired impact, a few others showed that pollution level decreased when the measure was rolled out.
The vehicle rationing scheme could reduce pollution level by just around 2-3%, a study done by a team of scientists from Indian Institutes of Technology (IIT) in Delhi, Kanpur, Indian Institute of Tropical Meteorology (IITM) in Pune, Council of Scientific and Industrial Research (CSIR) and the The Energy and Resources Institute (TERI), had concluded. Only three pockets of the city — Najafgarh, Shalimar Bagh and Greater Kailash — registered around 8-10% reduction in pollution.
A similar study by researchers of the environmental sciences and biomedical metrology division at the National Physical Laboratory and Jawaharlal Nehru University corroborated the findings of the IIT-IITM study.
“While on one hand, several vehicles would manage to pass through the gaps even on odd-even days, it is expected that the government would give a lot of exemptions. As a result, these short-term interventions are unlikely to produce the desired effect,” said SN Tripathi, head of the civil engineering department and earth sciences department at IIT, Kanpur.
Findings from a few other studies, however, backed the scheme. Experts from the Centre for Science and Environment suggested that as an “emergency measure”, the scheme prevented air pollution levels from getting worse. “Odd-even is an emergency measure that is rolled out when adverse meteorological conditions trap the local pollutants and air quality deteriorates. When such a situation arises, there is a clampdown on all sources, including industries and construction sites, but vehicles were kept out of the net. We must also tackle this source,” said Anumita Roy Chowdhury, executive director (research and advocacy), CSE.
Although questions loom over the efficacy of the vehicle rationing scheme in bringing down pollution in the national capital, experts from TERI, in their assessment of the scheme during the first phase at four monitoring stations — Mandir Marg, Punjabi Bagh, Anand Vihar and R K Puram — had stated that the plan did help decongest Delhi roads.
Experts said that the efficacy of the scheme would depend on the availability of public transport. If public transport is robust, the government would be in a position to include all vehicles in the scheme, including more than 60 lakh two-wheelers that contribute heavily to the city’s pollution.
“Transport sector contributes to around 25-28% of Delhi’s total pollution. If we can control this, we would be able to improve air quality. This is a welcome move, but it needs to be implemented without many exemptions. For that, you need a robust public transport system. Only then would we be able to see good results,” said D Saha, former head of the CPCB’s air quality laboratory.
First Published: Sep 13, 2019 21:58 IST