Stage 3 of the Graded Response Action Plan (GRAP), which came into effect on Friday, will take nearly 4 lakh vehicles out of roads in the two major UP cities of NCR.

GRAP 3 bars BS III (petrol and diesel) and BS IV (diesel) vehicles from plying in Delhi, Gurgaon, Faridabad, Ghaziabad and Gautam Budh Nagar. There are 1.8 lakh such vehicles in Gautam Budh Nagar and 2 lakh in Ghaziabad.

While police and transport department said they will strictly enforce the GRAP 3 directive, commuters said state govt needs to improve public transport, without which such bans cause great inconvenience.

Noida, with a total of 10.4 lakh registered vehicles, has 1.4 vehicles — 96,210 petrol and 41,067 diesel — under the BS III category. There are 41,516 BS IV diesel vehicles registered in the city too. Of the total of 1.7 BS III vehicles in Ghaziabad, 1.6 lakh are petrol and 10,931 diesel. Another 75,651 vehicles come under the BS IV diesel category.

Noida's assistant RTO (enforcement) Udit Narayan Pandey said the department will contact RWAs and AOAs and urge them to inform residents not to use vehicles that come under the restricted category. Checks on roads are also likely to go up and vehicles flouting GRAP 3 norms seized.

In the absence of a robust public transport network, commuters, especially those dependent on cars or cabs to reach their workplaces, said they will now have to scout for alternative modes of travel each morning.

Sanjeev Kumar of Sector 51, who owns a 2011 model Volkswagen Vento that falls in the BS III category, said vehicular emission was a significant contributor to PM 2.5 and 10 levels, but not the main culprit behind smog in Noida. Checks, he said, should be increased at the countless construction sites across the city that continue to violate GRAP norms — leave C&D debris uncovered, and fail to sprinkle water at these sites, among other things.

"The city already has a poor public transport system. In this condition, banning BS III and BS IV vehicles, which have PUC certifications, will only have a limited effect," he said.

Among other things, GRAP 3 bans construction and demolition activities and the movement of vehicles carrying C&D materials on unpaved roads.

Alok Singh of Alpha 1 in Greater Noida said he has a diesel-powered Hyundai Creta of BS IV model. "With the enforcement of GRAP 3, I can't use this car for commuting. I need my car for business purposes and also to drop my children to schools. I am figuring out how to cope with this situation as the ban has come into effect suddenly. I may use the Metro or autos for commuting. It's better to introduce an odd-even scheme as in that condition we can carpool with friends," he said.

Ghaziabad's Nehru Nagar resident Neeraj Sharma, an architect, said he is worried that BSIV petrol cars may also be banned in the coming days. "I have a Maruti Suzuki Dzire of BS IV model. But luckily it is a petrol vehicle and is exempted from the current ban. But in the coming days, if there are restrictions on this model too, I will be in trouble as I have to travel to Delhi frequently for work," he said.

BS IV petrol models are not banned under any of the four GRAP stages.

Meanwhile, Ghaziabad RTO PK Singh told TOI that the department would actively enforce the ban. On Friday, the two NCR cities recorded ‘very poor' air quality for the third consecutive day.