Motorists are being urged to check whether they will face a £12.50 daily fee when London’s pollution charge zone is extended.
The area in which drivers of older, more polluting vehicles are liable for the sum will be 18 times larger from Monday October 25.
The new charging zone will be expanded to include all areas within, but not including, the A406 North and South Circular roads.
Some 100,000 cars, 35,000 vans and 3,000 lorries could "potentially be affected" by the new rules every day, according to Transport for London estimates.
In the borough of Barnet, this means drivers travelling in the likes of Golders Green, Cricklewood, and East Finchley will have to comply with the new rules, but places near the A406 such as Finchley and Hendon don't fall within the zone.
For diesel cars to avoid the charge they must generally have been first registered after September 2015, while most petrol models registered from 2005 are also exempt.
Transport for London (TfL) said nearly 10 million people have used its online checker to find out whether they will be charged if they drive into the zone.
Residents living within the new wider ULEZ zone must pay the full daily charge to drive a vehicle in the zone if it does not meet the ULEZ standards - although there are some exemptions.
The charge applies all day, every day, except on Christmas Day.
TfL says signs at every entry point will tell you when you are entering the zone and advance information signs will be installed on surrounding major roads.
There are no barriers or toll booths. Instead, cameras will read your number plate as you drive within the zone and check it against TfL's database.
The Ultra Low Emission Zone (Ulez) has operated since April 2019, covering the same area of central London as the Congestion Charge.
Mayor of London Sadiq Khan said: "London’s toxic air is a health crisis causing long-lasting harm to our children and contributing to thousands of premature deaths.
"The Ultra Low Emission Zone has already cut nitrogen dioxide pollution by nearly half in central London and the expansion of the zone on October 25 means many more Londoners across the city will enjoy the benefits of cleaner, healthier air."
Alex Williams, TfL’s director of city planning, said: "We don’t want drivers to get caught out on October 25, we are advising people to use our checker to see if their vehicle meets the standards.
"If they are liable for the charge we would ask them to consider using public transport, or to walk or cycle if possible, and if they need to drive, consider using a car club whose fleets are fully Ulez compliant, or switching to the cleanest vehicle."
For more information visit https://tfl.gov.uk/modes/driving/ultra-low-emission-zone/ulez-expansion
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