Two-wheelers constitute two-thirds of Delhi’s vehicles, why the EV policy shift matters

The transport sector is among the most significant contributors to Delhi’s air pollution. While winter episodes of bad air get the most attention, vehicular emissions remain a persistent source of pollution through the year, making the transition to zero-emission vehicles a key component of the capital’s clean air strategy.

“The policy focuses on pure EVs, which offer superior environmental benefits as zero-emission vehicles,” the Delhi government said in a statement on Monday.

The policy cleared by the Delhi Cabinet cites the latest report of the Commission for Air Quality Management (CAQM), ‘Identification of the Causes for Worsening AQI in Delhi-NCR’, which estimates that vehicular emissions contribute around 23% of Delhi’s PM2.5 pollution during winter, making transport the single largest pollution source within the city.

Delhi CM Rekha Gupta at the Secretariat, Monday. (Express photo by Abhinav Saha)

The report notes that two-wheelers constitute nearly 67% of Delhi’s vehicle stock, making their rapid electrification critical for reducing emissions.

It also identifies three-wheelers, commercial cars and ‘N1’ category goods vehicles — with a gross vehicle weight of up to 3.5 tonnes — as priority segments because of their high daily utilisation and mileage, which result in disproportionately high emissions.

All of this has been flagged in earlier emissions inventories as well.

* A draft report by the nonprofit The Energy and Resources Institute (TERI) in 2021 identified vehicles as the single largest contributor to Delhi’s PM2.5 pollution through much of the pollution season.

Within the transport sector, two-wheelers were the largest contributors to PM2.5, PM10, sulphur dioxide and carbon monoxide emissions. Three-wheelers were found to be the largest source of volatile organic compounds (VOCs), while buses contributed the highest nitrogen oxides (NOx).

Across the National Capital Region (NCR), two-wheelers accounted for almost 31% of transport-related PM2.5 emissions and 51% of carbon monoxide emissions, the TERI inventory estimated.

* Earlier, a source apportionment study by IIT Kanpur had estimated that two-wheelers contributed about a third of vehicular PM2.5 and PM10 emissions in Delhi.

* An emissions inventory prepared under the Indian Institute of Tropical Meteorology’s System of Air Quality and Weather Forecasting and Research (SAFAR) in 2018 too identified transport as the biggest contributor to PM2.5 and NOx emissions, accounting for 41% and 76% respectively.

The CAQM report pointed out that emissions are influenced not only by the number of vehicles on the road but also by their age, mileage, fuel type, emission standards and maintenance.

Older vehicles, particularly those certified under pre-BS-VI norms, emitted substantially higher levels of pollutants because of engine deterioration and less effective emission-control systems.

It also noted that traffic congestion worsened emissions by causing inefficient combustion, and greater numbers of vehicle-kilometres travelled continued to increase the sector’s pollution burden.

A 2025 study by researchers at Delhi Technological University, which analysed exhaust emissions from 575 petrol-powered two-wheelers tested at Pollution Under Control centres in Delhi, found that besides age, vehicle mileage strongly influences emissions of carbon monoxide and hydrocarbons, and recommended that India’s vehicle scrappage policy should incorporate mileage in addition to age to identify highly polluting vehicles.

The CAQM has also pointed out that transport emissions extend beyond pollutants directly emitted from exhaust pipes. Nitrogen oxides and volatile organic compounds released by vehicles react in the atmosphere to form secondary particulate matter. These secondary particles account for about 27% of winter PM2.5 in Delhi and 17% during summer. Since they are formed through atmospheric chemical reactions rather than being emitted directly, controlling emissions from vehicles helps reduce not only primary pollutants but also the precursor gases responsible for secondary particle formation.

One of the biggest constraints to faster EV adoption has been the limited availability of public charging and battery-swapping infrastructure, particularly for commercial vehicles. The new EV policy envisages the establishment of more than 30,000 public charging points across the capital.

Just the numbers of two-wheelers in Delhi — two out of every three vehicles on the capital’s roads are two-wheelers — make the electrification mandate enormously significant.

Also, given that electric two-wheelers currently make up only about 7.5% of the total annual two-wheeler registrations in the capital — 36,962 out of 4,92,288 registrations in 2025 and 31,094 out of 4,15,336 registrations in 2024 — the policy has set a hugely ambitious target, looking to go to 100% in less than two years.

Several experts said that Delhi has led the country in making interventions in clean air policy over the decades, and that its EV policy can be expected to exercise considerable influence on the policies of other states as well. All of them, beginning with states in the NCR region, can be expected to now consider various electrification mandates.