Delhi’s ban on non-BS-VI petrol and diesel vehicles registered outside the capital begins on November 1, putting enforcement agencies across the National Capital Region under pressure as the winter pollution season intensifies. The restriction will remain in force for three months, until January 31, 2027.
The measure will affect older vehicles registered in Uttar Pradesh, Haryana and Rajasthan that do not meet the prescribed Bharat Stage VI emission standards. Around 48 lakh pre-BS-VI vehicles are registered in NCR districts adjoining Delhi, and these vehicles frequently enter and leave the capital, often daily.
The largest share is registered in Haryana. About 30.65 lakh vehicles, or more than 60 per cent of the total, are based in NCR districts including Gurugram, Faridabad, Rohtak, Sonipat, Jhajjar, Nuh, Rewari and Palwal. Uttar Pradesh accounts for around 11.8 lakh vehicles and Rajasthan for approximately 5.6 lakh.
Two-wheelers make up roughly three-quarters of the pre-BS-VI vehicles in the adjoining NCR districts, numbering about 36.5 lakh. Cars and cabs account for 7.26 lakh vehicles, or 15 per cent of the active stock. Goods vehicles, buses and tractors together account for about 2.9 lakh vehicles, or 6 per cent.
The heavier vehicle categories carry a significant diesel component. Diesel powers 81 per cent of goods vehicles, 70 per cent of buses and 93 per cent of tractors and farm vehicles in the regional stock described in the report. Diesel vehicles in these categories will therefore form an important part of enforcement at Delhi’s entry points.
Delhi Traffic Police officers told The Indian Express that implementing the restriction throughout winter will be difficult. Coordination with neighbouring districts will be necessary, particularly to prevent non-compliant vehicles from reaching the capital. Officers said that once a vehicle enters Delhi or reaches a flyover leading into the city, stopping and turning it around could create major congestion.
One officer said it would be impossible to ensure that every vehicle was sent back with the available manpower. Delhi has 23 entry points, while officials estimate that more than 12 lakh vehicles enter the capital every day. Police officers said deploying personnel to monitor every vehicle would not be feasible.
The restriction is being introduced against a backdrop of significant transport-related emissions. The Decision Support System, a numerical model-based framework developed by the Indian Institute of Tropical Meteorology, estimates that transport contributes 15-20 per cent of Delhi’s winter air pollution on average.
A draft 2021 emissions inventory prepared by The Energy and Resources Institute estimated that vehicles accounted for around 47 per cent of Delhi’s PM2.5 emissions, 78 per cent of nitrogen oxide emissions and 49 per cent of non-methane volatile organic compounds. It identified two-wheelers as the largest vehicular source of PM2.5, PM10, sulphur dioxide and carbon monoxide emissions.
The wider NCR faces a different emissions profile. The same inventory identified industries as the largest source of particulate pollution in the region, accounting for 44 per cent of PM2.5 and 41 per cent of PM10 emissions. Among vehicular sources, two-wheelers contributed the largest shares of PM2.5 and carbon monoxide, while buses contributed the largest share of vehicular nitrogen oxide emissions.
Heavy trucks remain another major concern. A joint study by IIT-Delhi and TERI reported that around 16,900 heavy-duty trucks enter Delhi each day. Although they represent only a fraction of total traffic, the study found that they generate 61 per cent of transport-related PM2.5 emissions between 10 pm and 7 am.
The entry restriction will therefore require enforcement across a transport network that includes private two-wheelers, cars, commercial vehicles, buses, tractors and long-haul trucks. Authorities have said coordination among Delhi and neighbouring NCR districts will be crucial as the three-month restriction takes effect on November 1.
